51
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Eskelinen A, Harpole WS, Jessen MT, Virtanen R, Hautier Y. Light competition drives herbivore and nutrient effects on plant diversity. Nature 2022; 611:301-305. [DOI: 10.1038/s41586-022-05383-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 09/23/2022] [Indexed: 11/06/2022]
Abstract
AbstractEnrichment of nutrients and loss of herbivores are assumed to cause a loss of plant diversity in grassland ecosystems because they increase plant cover, which leads to a decrease of light in the understory1–3. Empirical tests of the role of competition for light in natural systems are based on indirect evidence, and have been a topic of debate for the last 40 years. Here we show that experimentally restoring light to understory plants in a natural grassland mitigates the loss of plant diversity that is caused by either nutrient enrichment or the absence of mammalian herbivores. The initial effect of light addition on restoring diversity under fertilization was transitory and outweighed by the greater effect of herbivory on light levels, indicating that herbivory is a major factor that controls diversity, partly through light. Our results provide direct experimental evidence, in a natural system, that competition for light is a key mechanism that contributes to the loss of biodiversity after cessation of mammalian herbivory. Our findings also show that the effects of herbivores can outpace the effects of fertilization on competition for light. Management practices that target maintaining grazing by native or domestic herbivores could therefore have applications in protecting biodiversity in grassland ecosystems, because they alleviate competition for light in the understory.
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Brunbjerg AK, Fløjgaard C, Frøslev TG, Andersen DK, Bruun HH, Dalby L, Goldberg I, Lehmann LJ, Moeslund JE, Ejrnæs R. Scrub encroachment promotes biodiversity in temperate European wetlands under eutrophic conditions. Ecol Evol 2022; 12:e9445. [PMID: 36340817 PMCID: PMC9627074 DOI: 10.1002/ece3.9445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/29/2022] [Accepted: 10/03/2022] [Indexed: 11/05/2022] Open
Abstract
Wetlands are important habitats, often threatened by drainage, eutrophication, and suppression of grazing. In many countries, considerable resources are spent combatting scrub encroachment. Here, we hypothesize that encroachment may benefit biodiversity-especially under eutrophic conditions where asymmetric competition among plants compromises conservation targets. We studied the effects of scrub cover, nutrient levels, and soil moisture on the richness of vascular plants, bryophytes, soil fungi, and microbes in open and overgrown wetlands. We also tested the effect of encroachment, eutrophication, and soil moisture on indicators of conservation value (red-listed species, indicator species, and uniqueness). Plant and bryophyte species richness peaked at low soil fertility, whereas soil fertility promoted soil microbes. Soil fungi responded negatively to increasing soil moisture. Lidar-derived variables reflecting the degree of scrub cover had predominantly positive effects on species richness measures. Conservation value indicators had a negative relationship to soil fertility and a positive to encroachment. For plant indicator species, the negative effect of high nutrient levels was offset by encroachment, supporting our hypothesis of competitive release under shade. The positive effect of soil moisture on indicator species was strong in open habitats only. Nutrient-poor mires and meadows host many rare species and require conservation management by grazing and natural hydrology. On former agricultural lands, where restoration of infertile conditions is unfeasible, we recommend rewilding with opportunities for encroachment toward semi-open willow scrub and swamp forest, with the prospect of high species richness in bryophytes, fungi, and soil microbes and competitive release in the herb layer.
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Affiliation(s)
| | | | | | - Dagmar Kappel Andersen
- Department of EcoscienceAarhus UniversityAarhusDenmark
- Present address:
The Danish Nature AgencyRandbølDenmark
| | | | - Lars Dalby
- Department of EcoscienceAarhus UniversityAarhusDenmark
| | | | | | | | - Rasmus Ejrnæs
- Department of EcoscienceAarhus UniversityAarhusDenmark
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Veldhuis E, Skinkis J, Verheyen K, Smolders A, Smit C. Mycorrhizal fungi improve growth of Juniperus communis but only at sufficiently high soil element concentrations. Basic Appl Ecol 2022. [DOI: 10.1016/j.baae.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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54
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Wang J, Sha Z, Zhang J, Kang J, Xu W, Goulding K, Liu X. Reactive N emissions from cropland and their mitigation in the North China Plain. ENVIRONMENTAL RESEARCH 2022; 214:114015. [PMID: 35944622 DOI: 10.1016/j.envres.2022.114015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 07/23/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Excessive application of chemical nitrogen (N) fertilizer and inefficient N management are still common in the North China Plain, leading to large reactive N (Nr) losses and pollution, threatening environmental security and public health. Three improved N management practices (33% reduction in N applied (OU), OU combined with partial organic fertilizer substitution (UOM) and the urea in UOM amended with a urease inhibitor (ULOM)) together with no N application (CK) and farmers' conventional practice (CU) were tested on a maize-wheat rotation at Quzhou, Hebei, North China Plain (NCP). Nr emissions were related to WFPS (Water Filled Pore Space), soil mineral N (NH4+-N and NO3--N) and soil temperature. Nr emissions and yield-scaled Nr emissions were significantly reduced by partial substitution of organic fertilizer for chemical fertilizer: NH3 emissions were reduced by 55.8-62.4%. Using a urease inhibitor (Limus®), further reduced NH3 emissions by 40.2-64.5%. Yield-scaled NH3 emissions were, on average, reduced by 60.0% and 55.2% in the maize and wheat growing season, respectively, relative to the UOM treatment. Long-term application of organic fertilizer had a significant positive effect on N use efficiency (NUE). Overall, the study shows that appropriated N management such as reducing the N application rate, partial substitution of chemical N by organic N and using a urease inhibitor can reduce Nr emissions and promote NUE in the North China Plain. The methods corresponding to the ULOM and UOM treatments were the most and second most effective, respectively, with high net economic benefits.
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Affiliation(s)
- Jingxia Wang
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, 100193, Beijing, China
| | - Zhipeng Sha
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, 100193, Beijing, China; Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, 650500, Kunming, China
| | - Jinrui Zhang
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, 100193, Beijing, China
| | - Jiahui Kang
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, 100193, Beijing, China
| | - Wen Xu
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, 100193, Beijing, China
| | - Keith Goulding
- Sustainable Agricultural Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Xuejun Liu
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, 100193, Beijing, China.
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55
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Song W, Ochoa-Hueso R, Li F, Cui H, Zhong S, Yang X, Zhao T, Sun W. Mowing enhances the positive effects of nitrogen addition on ecosystem carbon fluxes and water use efficiency in a semi-arid meadow steppe. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 320:115889. [PMID: 35932732 DOI: 10.1016/j.jenvman.2022.115889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/19/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
Grasslands are now facing a continuously increasing supply of nitrogen (N) fertilizers, resulting in alterations in ecosystem functioning, including changes in carbon (C) and water cycling. Mowing, one of the most widely used grassland management techniques, has been shown to mitigate the negative impacts of increased N availability on species richness. However, knowledge of how N addition and mowing, alone and/or in combination, affect ecosystem-level C fluxes and water use efficiency (WN) is still limited. We experimentally manipulated N fertilization (0 and 10 g N m-2 yr-1) and mowing (once per year at the end of the growing season) following a randomized block design in a meadow steppe characterized by salinization and alkalinization in northeastern China. We found that, compared to the control plots, N addition, mowing, and their interaction increased net ecosystem CO2 exchange by 65.1%, 14.7%, and 133%, and WN by 40.7%, 18.5%, and 96.1%, respectively. Nitrogen enrichment also decreased soil pH, which resulted in greater aboveground biomass (AGB). Moreover, N addition indirectly increased AGB by inducing changes in species richness. Our results indicate that mowing enhances the positive effects of N addition on ecosystem C fluxes and WN. Therefore, appropriate grassland management practices are essential to improve ecosystem C sequestration, WN, and mitigate future species diversity declines due to ecosystem eutrophication.
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Affiliation(s)
- Wenzheng Song
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Department of Biology, IVAGRO, University of Cádiz, Campus de Excelencia Internacional Agroalimentario (ceiA3), Campus Del Rio San Pedro, 11510, Puerto Real, Cádiz, Spain
| | - Raúl Ochoa-Hueso
- Department of Biology, IVAGRO, University of Cádiz, Campus de Excelencia Internacional Agroalimentario (ceiA3), Campus Del Rio San Pedro, 11510, Puerto Real, Cádiz, Spain; Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700, AB, Wageningen, the Netherlands.
| | - Fei Li
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China
| | - Haiying Cui
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China
| | - Shangzhi Zhong
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Grassland Agri-Husbandry Research Center, College of Grassland Science, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xuechen Yang
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China; Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China
| | - Tianhang Zhao
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China
| | - Wei Sun
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun, 130024, China.
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56
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Jia X, Tao D, Ke Y, Li W, Yang T, Yang Y, He N, Smith MD, Yu Q. Dominant species control effects of nitrogen addition on ecosystem stability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156060. [PMID: 35618129 DOI: 10.1016/j.scitotenv.2022.156060] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/16/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Increased nitrogen (N) deposition is known to reduce the ecosystem stability, while the underlying mechanisms are still controversial. We conducted an 8-year multi-level N addition experiment in a temperate semi-arid grassland to identify the mechanisms (biodiversity, species asynchrony, population stability and dominant species stability) driving the N-induced loss of temporal stability of aboveground net primary productivity (ANPP). We found that N addition decreased ecosystem, population, and dominant species stability; decreased species richness and phylogenetic diversity; increased species dominance; but had nonsignificant effects on community-wide species asynchrony. Structural equation model revealed that N-induced loss of ecosystem stability was mainly driven by the loss of dominant species stability and the reduction in population stability. Moreover, species relative instability was negatively related with species relative production and the slopes increase with N addition, indicating that N addition weakened the stabilizing effect of dominant species on ecosystem function. Overall, our results highlight that the dominant species control the temporal stability of ANPP in grassland ecosystem under N addition, and support 'dominance management' as an effective strategy for conserving ecosystem functioning in grassland under N deposition.
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Affiliation(s)
- Xiaotong Jia
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Dongxue Tao
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yuguang Ke
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Wenjin Li
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Tian Yang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yadong Yang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Nianpeng He
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Melinda D Smith
- Department of Biology, Colorado State University, CO 80523, USA
| | - Qiang Yu
- School of Grassland Science, Beijing Forestry University, Beijing 100083, China.
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57
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Sebald V, Goss A, Ramm E, Gerasimova JV, Werth S. NO 2 air pollution drives species composition, but tree traits drive species diversity of urban epiphytic lichen communities. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 308:119678. [PMID: 35753543 DOI: 10.1016/j.envpol.2022.119678] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 06/12/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Lichens serve as important bioindicators of air pollution in cities. Here, we studied the diversity of epiphytic lichens in the urban area of Munich, Bavaria, southern Germany, to determine which factors influence species composition and diversity. Lichen diversity was quantified in altogether 18 plots and within each, five deciduous trees were investigated belonging to on average three tree species (range 1-5). Of the 18 plots, two were sampled in control areas in remote areas of southern Germany. For each lichen species, frequency of occurrence was determined in 10 quadrats of 100 cm2 on the tree trunk. Moreover, the cover percentage of bryophytes was determined and used as a variable to represent potential biotic competition. We related our diversity data (species richness, Shannon index, evenness, abundance) to various environmental variables including tree traits, i.e. bark pH levels and species affiliation and air pollution data, i.e. NO2 and SO2 concentrations measured in the study plots. The SO2 levels measured in our study were generally very low, while NO2 levels were rather high in some plots. We found that the species composition of the epiphytic lichen communities was driven mainly by NO2 pollution levels and all of the most common species in our study were nitrophilous lichens. Low NO2 but high SO2 values were associated with high lichen evenness. Tree-level lichen diversity and abundance were mainly determined by tree traits, not air pollution. These results confirm that ongoing NO2 air pollution within cities is a major threat to lichen diversity, with non-nitrophilous lichens likely experiencing the greatest risk of local extinctions in urban areas in the future. Our study moreover highlights the importance of large urban green spaces for species diversity. City planners need to include large green spaces when designing urban areas, both to improve biodiversity and to promote human health and wellbeing.
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Affiliation(s)
- Veronica Sebald
- Systematics and Ecology of Fungi and Algae, LMU Munich, Menzingerstraße 67, 80638 Munich, Germany
| | - Andrea Goss
- Systematics and Ecology of Fungi and Algae, LMU Munich, Menzingerstraße 67, 80638 Munich, Germany
| | - Elisabeth Ramm
- Systematics and Ecology of Fungi and Algae, LMU Munich, Menzingerstraße 67, 80638 Munich, Germany
| | - Julia V Gerasimova
- Systematics and Ecology of Fungi and Algae, LMU Munich, Menzingerstraße 67, 80638 Munich, Germany
| | - Silke Werth
- Systematics and Ecology of Fungi and Algae, LMU Munich, Menzingerstraße 67, 80638 Munich, Germany.
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58
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Li T, Cui L, Liu L, Wang H, Dong J, Wang F, Song X, Che R, Li C, Tang L, Xu Z, Wang Y, Du J, Hao Y, Cui X. Characteristics of nitrogen deposition research within grassland ecosystems globally and its insight from grassland microbial community changes in China. FRONTIERS IN PLANT SCIENCE 2022; 13:947279. [PMID: 35991446 PMCID: PMC9386444 DOI: 10.3389/fpls.2022.947279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
As global change continues to intensify, the mode and rate of nitrogen input from the atmosphere to grassland ecosystems had changed dramatically. Firstly, we conducted a systematic analysis of the literature on the topic of nitrogen deposition impacts over the past 30 years using a bibliometric analysis. A systematic review of the global research status, publication patterns, research hotspots and important literature. We found a large number of publications in the Chinese region, and mainly focuses on the field of microorganisms. Secondly, we used a meta-analysis to focus on microbial changes using the Chinese grassland ecosystem as an example. The results show that the research on nitrogen deposition in grassland ecosystems shows an exponential development trend, and the authors and research institutions of the publications are mainly concentrated in China, North America, and Western Europe. The keyword clustering results showed 11 important themes labeled climate change, elevated CO2, species richness and diversity, etc. in these studies. The burst keyword analysis indicated that temperature sensitivity, microbial communities, etc. are the key research directions. The results of the meta-analysis found that nitrogen addition decreased soil microbial diversity, and different ecosystems may respond differently. Treatment time, nitrogen addition rate, external environmental conditions, and pH had major effects on microbial alpha diversity and biomass. The loss of microbial diversity and the reduction of biomass with nitrogen fertilizer addition will alter ecosystem functioning, with dramatic impacts on global climate change. The results of the study will help researchers to further understand the subject and have a deep understanding of research hotspots, which are of great value to future scientific research.
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Affiliation(s)
- Tong Li
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- School of Environment and Science, Centre for Planetary Health and Food Security, Griffith University, Brisbane, QLD, Australia
| | - Lizhen Cui
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Lilan Liu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Hui Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
| | - Junfu Dong
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Fang Wang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- School of Environment and Science, Centre for Planetary Health and Food Security, Griffith University, Brisbane, QLD, Australia
| | - Xiufang Song
- National Science Library, Chinese Academy of Sciences, Beijing, China
- Department of Library, Information and Archives Management, School of Economics and Management, University of Chinese Academy of Sciences, Beijing, China
| | - Rongxiao Che
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming, China
| | - Congjia Li
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Li Tang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- School of Environment and Science, Centre for Planetary Health and Food Security, Griffith University, Brisbane, QLD, Australia
| | - Zhihong Xu
- School of Environment and Science, Centre for Planetary Health and Food Security, Griffith University, Brisbane, QLD, Australia
| | - Yanfen Wang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Tibetan Plateau Earth System Science (LATPES), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Jianqing Du
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- Beijing Yanshan Earth Critical Zone National Research Station, University of Chinese Academy of Sciences, Beijing, China
| | - Yanbin Hao
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- Beijing Yanshan Earth Critical Zone National Research Station, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoyong Cui
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- Beijing Yanshan Earth Critical Zone National Research Station, University of Chinese Academy of Sciences, Beijing, China
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59
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Wilcots ME, Schroeder KM, DeLancey LC, Kjaer SJ, Hobbie SE, Seabloom EW, Borer ET. Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland. GLOBAL CHANGE BIOLOGY 2022; 28:4819-4831. [PMID: 35593000 PMCID: PMC9545222 DOI: 10.1111/gcb.16272] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 05/22/2023]
Abstract
Changes in the biosphere carbon (C) sink are of utmost importance given rising atmospheric CO2 levels. Concurrent global changes, such as increasing nitrogen (N) deposition, are affecting how much C can be stored in terrestrial ecosystems. Understanding the extent of these impacts will help in predicting the fate of the biosphere C sink. However, most N addition experiments add N in rates that greatly exceed ambient rates of N deposition, making inference from current knowledge difficult. Here, we leveraged data from a 13-year N addition gradient experiment with addition rates spanning realistic rates of N deposition (0, 1, 5, and 10 g N m-2 year-1 ) to assess the rates of N addition at which C uptake and storage were stimulated in a temperate grassland. Very low rates of N addition stimulated gross primary productivity and plant biomass, but also stimulated ecosystem respiration such that there was no net change in C uptake or storage. Furthermore, we found consistent, nonlinear relationships between N addition rate and plant responses such that intermediate rates of N addition induced the greatest ecosystem responses. Soil pH and microbial biomass and respiration all declined with increasing N addition indicating that negative consequences of N addition have direct effects on belowground processes, which could then affect whole ecosystem C uptake and storage. Our work demonstrates that experiments that add large amounts of N may be underestimating the effect of low to intermediate rates of N deposition on grassland C cycling. Furthermore, we show that plant biomass does not reliably indicate rates of C uptake or soil C storage, and that measuring rates of C loss (i.e., ecosystem and soil respiration) in conjunction with rates of C uptake and C pools are crucial for accurately understanding grassland C storage.
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Affiliation(s)
- Megan E. Wilcots
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Katie M. Schroeder
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
- Odum School of EcologyUniversity of GeorgiaAthensGeorgiaUSA
| | - Lang C. DeLancey
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Savannah J. Kjaer
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Sarah E. Hobbie
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Eric W. Seabloom
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Elizabeth T. Borer
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
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60
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Brown JK, Moulton A, Zinnert JC. Plant community re-organization and increased productivity due to multi-year nutrient enrichment of a coastal grassland. PLoS One 2022; 17:e0270798. [PMID: 35901080 PMCID: PMC9333261 DOI: 10.1371/journal.pone.0270798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 06/19/2022] [Indexed: 11/18/2022] Open
Abstract
Nutrient enrichment alters plant community structure and function at a global scale. Coastal plant systems are expected to experience increased rates of nitrogen and phosphorus deposition by 2100, caused mostly by anthropogenic activity. Despite high density of studies investigating connections between plant community structure and ecosystem function in response to nutrient addition, inconsistencies in system response based on the ecosystem in question calls for more detailed analyses of nutrient impacts on community organization and resulting productivity response. Here, we focus on nutrient addition impacts on community structure and organization as well as productivity of different lifeforms in a coastal grassland. We established long-term nutrient enrichment plots in 2015 consisting of control (C), nitrogen (N), phosphorus (P), and nitrogen + phosphorus (NP) treatments. In 2017 we collected graminoid and forb productivity, root productivity, and community composition for each plot. We found no N x P interaction, but N enrichment was a significant main effect on productivity, highlighting N limitation in coastal systems. Importantly, nutrient enrichment treatments did not alter root productivity. However, all treatments caused significant differences in community composition. Using rank abundance curves, we determined that community composition differences were driven by increased dominance of nitrophilous graminoids, re-organization of subordinate species, and species absences in N and NP plots. Results of this study highlight how coastal grassland communities are impacted by nutrient enrichment. We show that community re-organization, increased dominance, and absence of critical species are all important mechanisms that reflect community-level impacts of nutrient enrichment in our coastal grassland site.
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Affiliation(s)
- Joseph K. Brown
- Department of Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Biological Sciences, Minnesota State University, Mankato, Minnesota, United States of America
| | - Ashley Moulton
- Department of Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Julie C. Zinnert
- Department of Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
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61
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Rong X, Zhou X, Li X, Yao M, Lu Y, Xu P, Yin B, Li Y, Aanderud ZT, Zhang Y. Biocrust diazotrophs and bacteria rather than fungi are sensitive to chronic low N deposition. Environ Microbiol 2022; 24:5450-5466. [PMID: 35844197 DOI: 10.1111/1462-2920.16095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 06/03/2022] [Indexed: 11/03/2022]
Abstract
Anthropogenic long-term nitrogen (N) deposition may dramatically impact biocrusts due to the overarching N limitation of soil biota in deserts. Even low levels of N may reach a critical loading threshold altering biocrust constituents and function. To identify the impact of chronic and continuous low levels of N deposition on biocrusts, we created a realistic gradient mirroring anthropogenic N addition rate (2:1 NH4 + : NO3 - rates: 0.3, 0.5, 1.0, 1.5, 3 g N m-2 yr-1 ) and measured the response of bacteria and fungi within cyanobacterial-dominated biocrusts over 8 years in a temperate desert, the Gurbantunggut Desert, China. We found that once N deposition reached 1.5 g N m-2 yr-1 biocrust bacterial communities, including diazotrophs, were altered while no such tipping point existed for fungi. Above the threshold, bacterial richness was enhanced, the relative abundance of Chloroflexi, FBP and Gemmatimonadetes was elevated, and diazotrophs shifted from being dominated by Nostocaceae and Scytonemataceae (Cyanobacteria) to free-living Bradyrhizobiaceae (Alphaproteobacteria). Alternatively, the relative recovery of a few fungal species within the Lecanorales, Pleosporales and Verrucariales became either enriched or diminished due to N deposition. The chronic addition of N resulted in a dense and interconnected bacterial co-occurrence network that accentuated a functional shift from networks dominated by phototrophic species within the Nostocaceae, Xenococcaceae, Phormidiaceae and Scytonemataceae (Cyanobacteria) to ammonia-oxidizing species within the Nitrosomonadaceae (Betaproteobacteria) and nitrifying bacteria [i.e. Nitrospiraceae (Nitrospirae)]. Based on structural equation models, the effects of N additions on biocrust constituents were imposed through indirect effects on pH, soil electrical conductivity and ammonium concentrations. In summary, biocrust constituents are generally insensitive to chronic low levels of N depositions until rates reach above 1.5 g N m-2 yr-1 with diazotrophs being the most sensitive biocrust constituents followed by bacteria and finally fungi. Ultimately once the threshold is reached N deposition favours biocrust constituents utilizing inorganic N and other C sources over relying on phototrophic and/or N-fixing cyanobacteria for C and N.
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Affiliation(s)
- Xiaoying Rong
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Xiaobing Zhou
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Xiangzhen Li
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, and Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Minjie Yao
- College of Resources and Environment, Fujian Agriculture and Forest University, Fuzhou, China
| | - Yongxing Lu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.,University of the Chinese Academy of Sciences, Beijing, China
| | - Peng Xu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.,University of the Chinese Academy of Sciences, Beijing, China
| | - Benfeng Yin
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Yonggang Li
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Zachary T Aanderud
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, USA
| | - Yuanming Zhang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
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Shao W, Wang Q, Guan Q, Luo H, Ma Y, Zhang J. Distribution of soil available nutrients and their response to environmental factors based on path analysis model in arid and semi-arid area of northwest China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:154254. [PMID: 35248639 DOI: 10.1016/j.scitotenv.2022.154254] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 02/26/2022] [Accepted: 02/26/2022] [Indexed: 06/14/2023]
Abstract
The study on the distribution of soil available nutrients and their response to the natural environment can provide valuable data and theoretical guidance for supporting human agricultural activities, especially in arid and semi-arid area where the ecological environment is extremely fragile. Based on the soil sampling and survey data set, this study established the path analysis model of SANs (soil available nutrients, including ammonium nitrogen (AN), available phosphorus (AP) and available potassium (AK)) with topography, climate and vegetation in order to explore how environmental factors interact to affect the content of SANs. Then, we combined Pearson correlation analysis and statistical analysis to explore the distribution of SANs under different environmental conditions and the response of vegetation growth to climate changes, in order to further reveal the availability of soil nutrients. The results showed that vegetation was the most important direct factor affecting AN and AP, and AK was the most sensitive to climate changes. The indirect effects of topography and climate on SANs were much greater than their direct effects. Elevation largely predicted the change of climate environment, and the regional climate directly controlled the growth of vegetation. These indirect effects strengthened the connection between topography as well as climate factors and SANs. It is worth noting that the response of vegetation to temperature and precipitation had time lag, which would have a certain impact on the content of SANs response to the environmental changes. This study is of great significance for improved understanding of soil nutrients supply and how ecosystems respond to soil nutrients availability in arid and semi-arid area.
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Affiliation(s)
- Wenyan Shao
- Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Qingzheng Wang
- Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Qingyu Guan
- Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China.
| | - Haiping Luo
- Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yunrui Ma
- Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Jun Zhang
- Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
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Qin S, Yang G, Zhang Y, Song M, Sun L, Cui Y, Dong J, Wang N, Liu X, Zheng P, Wang R. Mowing Did Not Alleviate the Negative Effect of Nitrogen Addition on the Arbuscular Mycorrhizal Fungal Community in a Temperate Meadow Grassland. FRONTIERS IN PLANT SCIENCE 2022; 13:917645. [PMID: 35755642 PMCID: PMC9228033 DOI: 10.3389/fpls.2022.917645] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
As nitrogen deposition intensifies under global climate change, understanding the responses of arbuscular mycorrhizal (AM) fungi to nitrogen deposition and the associated mechanisms are critical for terrestrial ecosystems. In this study, the effects of nitrogen addition and mowing on AM fungal communities in soil and mixed roots were investigated in an Inner Mongolia grassland. The results showed that nitrogen addition reduced the α-diversity of AM fungi in soil rather than that of root. Besides, nitrogen addition altered the composition of AM fungal community in soil. Soil pH and inorganic nitrogen content were the main causes of changes in AM fungal communities affected by nitrogen addition. Mowing and the interaction of nitrogen addition and mowing had no significant effect on AM fungal community diversity. In contrast, while mowing may reduce the negative effects of nitrogen addition on the richness and diversity of plants by alleviating light limitation, it could not do so with the negative effects on AM fungal communities. Furthermore, AM fungal communities clustered phylogenetically in all treatments in both soil and roots, indicating that environmental filtering was the main driving force for AM fungal community assembly. Our results highlight the different responses of AM fungi in the soil and roots of a grassland ecosystem to nitrogen addition and mowing. The study will improve our understanding of the effects of nitrogen deposition on the function of ecosystem.
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Affiliation(s)
- Siqi Qin
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Guojiao Yang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- College of Ecology and Environment, Hainan University, Haikou, China
| | - Yang Zhang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Meixia Song
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Lu Sun
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Yangzhe Cui
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Jibin Dong
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Ning Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Xiao Liu
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Peiming Zheng
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
| | - Renqing Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Jinan, China
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Fan MY, Zhang YL, Lin YC, Hong Y, Zhao ZY, Xie F, Du W, Cao F, Sun Y, Fu P. Important Role of NO 3 Radical to Nitrate Formation Aloft in Urban Beijing: Insights from Triple Oxygen Isotopes Measured at the Tower. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6870-6879. [PMID: 34428888 DOI: 10.1021/acs.est.1c02843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Until now, there has been a lack of knowledge regarding the vertical profiles of nitrate formation in the urban boundary layer (BL) based on triple oxygen isotopes. Here, we conducted vertical measurements of the oxygen anomaly of nitrate (Δ17O-NO3-) on a 325 m meteorological tower in urban Beijing during the winter and summer. The simultaneous vertical measurements suggested different formation mechanisms of nitrate aerosols at ground level and 120 and 260 m in the winter due to the less efficient vertical mixing under stable atmospheric conditions. Particularly, different chemical processes of nitrate aerosols at the three heights were found between clean days and polluted days in the winter. On clean days, nocturnal chemistry (NO3 + HC and N2O5 uptake) contributed to nitrate production equally with OH/H2O + NO2 at ground level, while it dominated aloft (contributing 80% of nitrate production at 260 m), due to the higher aerosol liquid water content and O3 concentration there. On polluted days, nocturnal reactions dominated the formation of nitrate at the three heights. Particularly, the contribution of the OH/H2O + NO2 pathway to nitrate production increased from the ground level to 120 m might be attributed to the hydrolysis of NO2 to HONO and then further photolysis to OH radicals in the day. In contrast, the proportion of N2O5 + H2O decreased at 260 m, likely due to the low relative humidity aloft that inhibited the N2O5 hydrolysis reactions in the residual layer. Our results highlighted that the differences between meteorology and gaseous precursors could largely affect particulate nitrate formation at different heights within the polluted urban BL.
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Affiliation(s)
- Mei-Yi Fan
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Key Laboratory Meteorological Disaster, Ministry of Education & Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Jiangsu Provincial Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, People's Republic of China
| | - Yan-Lin Zhang
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Key Laboratory Meteorological Disaster, Ministry of Education & Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Jiangsu Provincial Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, People's Republic of China
| | - Yu-Chi Lin
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Key Laboratory Meteorological Disaster, Ministry of Education & Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Jiangsu Provincial Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, People's Republic of China
| | - Yihang Hong
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Key Laboratory Meteorological Disaster, Ministry of Education & Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Jiangsu Provincial Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, People's Republic of China
| | - Zhu-Yu Zhao
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Key Laboratory Meteorological Disaster, Ministry of Education & Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Jiangsu Provincial Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, People's Republic of China
| | - Feng Xie
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Key Laboratory Meteorological Disaster, Ministry of Education & Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Jiangsu Provincial Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, People's Republic of China
| | - Wei Du
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, People's Republic of China
- Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
| | - Fang Cao
- Yale-NUIST Center on Atmospheric Environment, International Joint Laboratory on Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Key Laboratory Meteorological Disaster, Ministry of Education & Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 210044, People's Republic of China
- Jiangsu Provincial Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, People's Republic of China
| | - Yele Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, People's Republic of China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Pingqing Fu
- Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, People's Republic of China
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Interactions between tall oatgrass invasion and soil nitrogen cycling. Oecologia 2022; 199:419-426. [PMID: 35670872 PMCID: PMC9226098 DOI: 10.1007/s00442-022-05192-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 05/20/2022] [Indexed: 11/18/2022]
Abstract
Increases in nitrogen (N) inputs to the biosphere can exacerbate the introduction and spread of invasive non-native plant species. Often, with elevated soil N levels, invasive plants establish and further enrich soil N pools, changing overall ecosystem function. This study examined the relationship between soil N cycling and an increasingly prevalent, invasive plant species, tall oatgrass (Arrhenatherum elatius subsp. elatius), in foothills ecosystems between the Colorado Rocky Mountains and the Denver-Boulder Metropolitan area—similar to many Western US grasslands and woodlands. It focused on investigating differences in soil N transformations, inorganic N pools, and vegetation characteristics across invaded and uninvaded plots at three sites in two seasons (summer and autumn). There was a statistically significant effect of invasion on rates of net N mineralization, but it was dependent on site and season (p = 0.046). Site had a statistically significant effect on soil moisture and aboveground biomass C:N (p < 0.04). The interactions of invasion x site were statistically significant for ammonium pools (p < 0.03). These findings suggest that A. elatius invasion can be associated with accelerated N cycling, but that the nature of the relationship differs by location and season in the foothills. More broadly, this study contributes to determining how the N cycle is shifting in grassland ecosystems subject to increasing pressures from anthropogenic change.
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66
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Unexpected response of nitrogen deposition to nitrogen oxide controls and implications for land carbon sink. Nat Commun 2022; 13:3126. [PMID: 35668096 PMCID: PMC9170707 DOI: 10.1038/s41467-022-30854-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 05/20/2022] [Indexed: 11/26/2022] Open
Abstract
Terrestrial ecosystems in China receive the world’s largest amount of reactive nitrogen (N) deposition. Recent controls on nitrogen oxides (NOx = NO + NO2) emissions in China to tackle air pollution are expected to decrease N deposition, yet the observed N deposition fluxes remain almost stagnant. Here we show that the effectiveness of NOx emission controls for reducing oxidized N (NOy = NOx + its oxidation products) deposition is unforeseen in Eastern China, with one-unit reduction in NOx emission leading to only 55‒76% reductions in NOy-N deposition, as opposed to the high effectiveness (around 100%) in both Southern China and the United States. Using an atmospheric chemical transport model, we demonstrate that this unexpected weakened response of N deposition is attributable to the enhanced atmospheric oxidizing capacity by NOx emissions reductions. The decline in N deposition could bear a penalty on terrestrial carbon sinks and should be taken into account when developing pathways for China’s carbon neutrality. Recent vigorous controls in anthropogenic nitrogen oxide emissions in China cannot result in proportionate decreases in regional atmospheric nitrogen deposition. Enhanced atmospheric oxidizing capacity offsets those reductions of precursor emissions.
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Song W, Liu XY, Houlton BZ, Liu CQ. Isotopic constraints confirm the significant role of microbial nitrogen oxides emissions from the land and ocean environment. Natl Sci Rev 2022; 9:nwac106. [PMID: 36128454 PMCID: PMC9477198 DOI: 10.1093/nsr/nwac106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 05/28/2022] [Accepted: 05/31/2022] [Indexed: 12/02/2022] Open
Abstract
Nitrogen oxides (NOx, the sum of nitric oxide (NO) and N dioxide (NO2)) emissions and deposition have increased markedly over the past several decades, resulting in many adverse outcomes in both terrestrial and oceanic environments. However, because the microbial NOx emissions have been substantially underestimated on the land and unconstrained in the ocean, the global microbial NOx emissions and their importance relative to the known fossil-fuel NOx emissions remain unclear. Here we complied data on stable N isotopes of nitrate in atmospheric particulates over the land and ocean to ground-truth estimates of NOx emissions worldwide. By considering the N isotope effect of NOx transformations to particulate nitrate combined with dominant NOx emissions in the land (coal combustion, oil combustion, biomass burning and microbial N cycle) and ocean (oil combustion, microbial N cycle), we demonstrated that microbial NOx emissions account for 24 ± 4%, 58 ± 3% and 31 ± 12% in the land, ocean and global environment, respectively. Corresponding amounts of microbial NOx emissions in the land (13.6 ± 4.7 Tg N yr−1), ocean (8.8 ± 1.5 Tg N yr−1) and globe (22.5 ± 4.7 Tg N yr−1) are about 0.5, 1.4 and 0.6 times on average those of fossil-fuel NOx emissions in these sectors. Our findings provide empirical constraints on model predictions, revealing significant contributions of the microbial N cycle to regional NOx emissions into the atmospheric system, which is critical information for mitigating strategies, budgeting N deposition and evaluating the effects of atmospheric NOx loading on the world.
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Affiliation(s)
- Wei Song
- School of Earth System Science, Tianjin University , Tianjin , 300072 , China
| | - Xue-Yan Liu
- School of Earth System Science, Tianjin University , Tianjin , 300072 , China
| | - Benjamin Z Houlton
- Department of Global Development and Department of Ecology and Evolutionary Biology, Cornell University , Ithaca, NY 14850 , USA
| | - Cong-Qiang Liu
- School of Earth System Science, Tianjin University , Tianjin , 300072 , China
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Yu C, Wang Q, Zhang S, Zeng H, Chen W, Chen W, Lou H, Yu W, Wu J. Effects of Strigolactone on Torreya grandis Gene Expression and Soil Microbial Community Structure Under Simulated Nitrogen Deposition. FRONTIERS IN PLANT SCIENCE 2022; 13:908129. [PMID: 35720604 PMCID: PMC9201785 DOI: 10.3389/fpls.2022.908129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/02/2022] [Indexed: 06/15/2023]
Abstract
Nitrogen enters the terrestrial ecosystem through deposition. High nitrogen levels can affect physical and chemical properties of soil and inhibit normal growth and reproduction of forest plants. Nitrogen modulates the composition of soil microorganisms. Strigolactones inhibits plant branching, promotes root growth, nutrient absorption, and promotes arbuscular fungal mycelia branching. Plants are subjected to increasing atmospheric nitrogen deposition. Therefore, it is imperative to explore the relationship between strigolactone and nitrogen deposition of plants and abundance of soil microorganisms. In the present study, the effects of strigolactone on genetic responses and soil microorganisms of Torreya grandis, under simulated nitrogen deposition were explored using high-throughput sequencing techniques. T. grandis is a subtropical economic tree species in China. A total of 4,008 differentially expressed genes were identified in additional N deposition and GR24 treatment. These genes were associated with multiple GO terms and metabolic pathways. GO enrichment analysis showed that several DEGs were associated with enrichment of the transporter activity term. Both additional nitrogen deposition and GR24 treatment modulated the content of nutrient elements. The content of K reduced in leaves after additional N deposition treatment. The content of P increased in leaves after GR24 treatment. A total of 20 families and 29 DEGs associated with transporters were identified. These transporters may be regulated by transcription factors. A total of 1,402,819 clean reads and 1,778 amplicon sequence variants (ASVs) were generated through Bacterial 16S rRNA sequencing. Random forest classification revealed that Legionella, Lacunisphaera, Klebsiella, Bryobacter, and Janthinobacterium were significantly enriched in the soil in the additional N deposition group and the GR24 treatment group. Co-occurrence network analysis showed significant differences in composition of soil microbial community under different treatments. These results indicate a relationship between N deposition and strigolactones effect. The results provide new insights on the role of strigolactones in plants and composition of soil microorganisms under nitrogen deposition.
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Affiliation(s)
- Chenliang Yu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Qi Wang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Shouke Zhang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Hao Zeng
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Weijie Chen
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Wenchao Chen
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Heqiang Lou
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Weiwu Yu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
- NFGA Engineering Research Center for Torreya grandis ‘Merrillii’, Zhejiang A&F University, Hangzhou, China
| | - Jiasheng Wu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
- NFGA Engineering Research Center for Torreya grandis ‘Merrillii’, Zhejiang A&F University, Hangzhou, China
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Tian Q, Lu P, Zhai X, Zhang R, Zheng Y, Wang H, Nie B, Bai W, Niu S, Shi P, Yang Y, Li K, Yang D, Stevens C, Lambers H, Zhang WH. An integrated belowground trait-based understanding of nitrogen-driven plant diversity loss. GLOBAL CHANGE BIOLOGY 2022; 28:3651-3664. [PMID: 35231142 DOI: 10.1111/gcb.16147] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
Belowground plant traits play important roles in plant diversity loss driven by atmospheric nitrogen (N) deposition. However, the way N enrichment shapes plant microhabitats by patterning belowground traits and finally determines aboveground responses is poorly understood. Here, we investigated the rhizosheath trait of 74 plant species in seven N-addition simulation experiments across multiple grassland ecosystems in China. We found that rhizosheath formation differed among plant functional groups and contributed to changes in plant community composition induced by N enrichment. Compared with forb species, grass and sedge species exhibited distinct rhizosheaths; moreover, grasses and sedges expanded their rhizosheaths with increasing N-addition rate which allowed them to colonize belowground habitats. Grasses also shaped a different microenvironment around their roots compared with forbs by affecting the physicochemical, biological, and stress-avoiding properties of their rhizosphere soil. Rhizosheaths act as a "biofilm-like shield" by the accumulation of protective compounds, carboxylic anions and polysaccharides, determined by both plants and microorganisms. This enhanced the tolerance of grasses and sedges to stresses induced by N enrichment. Conversely, forbs lacked the protective rhizosheaths which renders their roots sensitive to stresses induced by N enrichment, thus contributing to their disappearance under N-enriched conditions. This study uncovers the processes by which belowground facilitation and trait matching affect aboveground responses under conditions of N enrichment, which advances our mechanistic understanding of the contribution of competitive exclusion and environmental tolerance to plant diversity loss caused by N deposition.
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Affiliation(s)
- Qiuying Tian
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Peng Lu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xiufeng Zhai
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Ruifang Zhang
- Mountain Area Research Institute, Agricultural University of Hebei, Baoding, China
| | - Yao Zheng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Hong Wang
- Mountain Area Research Institute, Agricultural University of Hebei, Baoding, China
| | - Bao Nie
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Wenming Bai
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Shuli Niu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Peili Shi
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Yuanhe Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Kaihui Li
- Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Dianlin Yang
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, China
| | - Carly Stevens
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Hans Lambers
- School of Biological Sciences and Institute of Agriculture, University of Western Australia, Perth, Western Australia, Australia
- National Academy for Green Agriculture, China Agricultural University, Beijing, China
| | - Wen-Hao Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
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70
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Zhang M, Li X, Xing F, Li Z, Liu X, Li Y. Soil Microbial Legacy Overrides the Responses of a Dominant Grass and Nitrogen-Cycling Functional Microbes in Grassland Soil to Nitrogen Addition. PLANTS (BASEL, SWITZERLAND) 2022; 11:1305. [PMID: 35631730 PMCID: PMC9145027 DOI: 10.3390/plants11101305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/03/2022] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
Both atmospheric nitrogen (N) deposition and soil microbial legacy (SML) can affect plant performance, the activity of soil N-cycling functional microbes and the relative abundance of N-cycling functional genes (NCFGs). In the grassland vegetation successional process, how the interaction of SML and N deposition affects the performance of dominant grass and NCFGs remains unclear. Therefore, we planted Leymus chinensis, a dominant grass in the Songnen grassland, in the soil taken from the early, medium, late, and stable successional stages. We subjected the plants to soil sterilization and N addition treatments and measured the plant traits and NCFG abundances (i.e., nifH, AOB amoA, nirS, and nirK). Our results showed the biomass and ramet number of L. chinensis in sterilized soil were significantly higher than those in non-sterilized soil, indicating that SML negatively affects the growth of L. chinensis. However, N addition increased the plant biomass and the AOB amoA gene abundance only in sterilized soils, implying that SML overrode the N addition effects because SML buffered the effects of increasing soil N availability on NCFGs. Therefore, we emphasize the potential role of SML in assessing the effects of N deposition on dominant plant performance and NCFGs in the grassland vegetation succession.
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Affiliation(s)
- Minghui Zhang
- Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China; (M.Z.); (X.L.); (Z.L.); (X.L.); (Y.L.)
- Jilin Provincial Key Laboratory of Ecological Restoration and Ecosystem Management, Northeast Normal University, Changchun 130024, China
| | - Xueli Li
- Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China; (M.Z.); (X.L.); (Z.L.); (X.L.); (Y.L.)
- Jilin Provincial Key Laboratory of Ecological Restoration and Ecosystem Management, Northeast Normal University, Changchun 130024, China
| | - Fu Xing
- Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China; (M.Z.); (X.L.); (Z.L.); (X.L.); (Y.L.)
- Jilin Provincial Key Laboratory of Ecological Restoration and Ecosystem Management, Northeast Normal University, Changchun 130024, China
| | - Zhuo Li
- Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China; (M.Z.); (X.L.); (Z.L.); (X.L.); (Y.L.)
- Jilin Provincial Key Laboratory of Ecological Restoration and Ecosystem Management, Northeast Normal University, Changchun 130024, China
| | - Xiaowei Liu
- Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China; (M.Z.); (X.L.); (Z.L.); (X.L.); (Y.L.)
- Jilin Provincial Key Laboratory of Ecological Restoration and Ecosystem Management, Northeast Normal University, Changchun 130024, China
| | - Yanan Li
- Key Laboratory of Vegetation Ecology, Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China; (M.Z.); (X.L.); (Z.L.); (X.L.); (Y.L.)
- Jilin Provincial Key Laboratory of Ecological Restoration and Ecosystem Management, Northeast Normal University, Changchun 130024, China
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71
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Wilkins K, Clark C, Aherne J. Ecological thresholds under atmospheric nitrogen deposition for 1200 herbaceous species and 24 communities across the United States. GLOBAL CHANGE BIOLOGY 2022; 28:2381-2395. [PMID: 34986509 PMCID: PMC9770646 DOI: 10.1111/gcb.16076] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/26/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Nitrogen (N) emissions and atmospheric deposition have increased significantly during the last century and become a stressor for many N-sensitive plant species. Understanding individual and community herbaceous plant species thresholds to atmospheric N deposition can inform emissions reduction policy. Here, we present results using Threshold Indicator Taxa Analysis (TITAN) applied to more than 1200 unique plant species and 24 vegetation communities (i.e., alliances) across the United States (US) to assess vulnerability to N deposition. Alliance-level thresholds (change points) for species decreasing in abundance along the gradient ranged from 1.8 to 14.3 kg N ha─1 year─1 and tended to be lower in the west than the east, which suggests that eastern communities, where N deposition has been historically higher, may have already lost many sensitive species. For the species that were present in more than one alliance, over half had a variable response to the N deposition gradient, suggesting that local factors affect vulnerability. Significant progress has been made during the past 30 years to reduce N emissions, which has reduced the percentage of plots at risk to N deposition from 72% to 35%. Nevertheless, over a third of plots remain at risk, and an average reduction of N deposition of 20% would protect half of the plots where N deposition exceeds community thresholds. Furthermore, the alliance- and species-level change points determined in this study may be used to inform N critical loads.
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Affiliation(s)
- Kayla Wilkins
- School of the Environment, Trent University, Peterborough, Ontario, Canada
| | - Christopher Clark
- Integrated Environmental Assessment Branch, US Environmental Protection Agency, Washington, DC, USA
| | - Julian Aherne
- School of the Environment, Trent University, Peterborough, Ontario, Canada
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72
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Wang G, Koziol L, Foster BL, Bever JD. Microbial mediators of plant community response to long-term N and P fertilization: Evidence of a role of plant responsiveness to mycorrhizal fungi. GLOBAL CHANGE BIOLOGY 2022; 28:2721-2735. [PMID: 35048483 DOI: 10.1111/gcb.16091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/26/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Climate changes and anthropogenic nutrient enrichment widely threaten plant diversity and ecosystem functions. Understanding the mechanisms governing plant species turnover across nutrient gradients is crucial to developing successful management and restoration strategies. We tested whether and how soil microbes, particularly arbuscular mycorrhizal fungi (AMF), could mediate plant community response to a 15 years long-term N (0, 4, 8, and 16 g N m-2 year-1 ) and P (0 and 8 g N m-2 year-1 ) enrichment in a grassland system. We found N and P enrichment resulted in plant community diversity decrease and composition change, in which perennial C4 graminoids were dramatically reduced while annuals and perennial forbs increased. Metabarcoding analysis of soil fungal community showed that N and P changed fungal diversity and composition, of which only a cluster of AMF identified by the co-occurrence networks analysis was highly sensitive to P treatments and was negatively correlated with shifts in percentage cover of perennial C4 graminoids. Moreover, by estimating the mycorrhizal responsiveness (MR) of 41 plant species in the field experiment from 264 independent tests, we found that the community weighted mean MR of the plant community was substantially reduced with nutrient enrichment and was positively correlated with C4 graminoids percentage cover. Both analyses of covariance and structural equation modeling indicated that the shift in MR rather than AMF composition change was the primary predictor of the decline in perennial C4 graminoids, suggesting that the energy cost invested by C4 plants on those sensitive AMF might drive the inferior competitive abilities compared with other groups. Our results suggest that shifts in the competitive ability of mycorrhizal responsive plants can drive plant community change to anthropogenic eutrophication, suggesting a functional benefit of mycorrhizal mutualism in ecological restoration following climatic or anthropogenic degradation of soil communities.
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Affiliation(s)
- Guangzhou Wang
- College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, People's Republic of China
- Kansas Biological Survey, University of Kansas, Lawrence, Kansas, USA
| | - Liz Koziol
- Kansas Biological Survey, University of Kansas, Lawrence, Kansas, USA
| | - Bryan L Foster
- Kansas Biological Survey, University of Kansas, Lawrence, Kansas, USA
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, USA
| | - James D Bever
- Kansas Biological Survey, University of Kansas, Lawrence, Kansas, USA
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas, USA
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73
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Effects of 5-Year Nitrogen Addition on Species Composition and Diversity of an Alpine Steppe Plant Community on Qinghai-Tibetan Plateau. PLANTS 2022; 11:plants11070966. [PMID: 35406946 PMCID: PMC9002499 DOI: 10.3390/plants11070966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/26/2022] [Accepted: 03/29/2022] [Indexed: 11/29/2022]
Abstract
The N deposition rate is notably increased in China, especially in the Qinghai-Tibetan Plateau (QTP). How plants respond to the projected N deposition on the alpine steppe is still in debate. In this study, to investigate the effects of N deposition on the plant community of the alpine steppe, we simulated N deposition at six different N addition rate levels (0, 8, 24, 40, 56, 72 kg N ha−1 y−1) from 2015 to 2019. Species composition and diversity were investigated as the assessment indices. The results showed that the importance value of grasses significantly increased with the increase of the N addition rate, while that of forbs significantly decreased. A high N addition rate (72 kg N ha−1 y−1) induced species composition change, making Leymus secalinus become the most dominant species within the entire plant community. Compared with the control (without N addition), species richness, Shannon–Weiner diversity, Simpson dominance and Pielou Evenness were significantly reduced under a high N addition rate. The changes of plant diversity in the alpine steppe were closely correlated with dynamics of soil nutrients, especially total carbon (TC), total phosphorus (TP) and ammonia nitrogen (NH4-N). Our findings suggested that a high N deposition rate (72 kg N ha−1 y−1) could significantly change plant composition and reduce the diversity of the alpine steppe, though they were less affected by low N deposition rates at present. With the increase of the N deposition rate, plant composition and diversity of the alpine steppe may be negatively affected in the future. In addition, Leymus secalinus is more competitive than other species with an N deposition rate increase. Soil C, soil P and soil NH4-N variation induced by N deposition might play a key role in regulating changes in plant composition and diversity in the alpine steppe. In addition, longer term field investigation needs to be carried out to testify to this phenomenon with the increase of N deposition in the future.
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74
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Zettlemoyer MA. Monitoring demography of resurrected populations of locally extinct and extant species to investigate drivers of species loss. Am Nat 2022; 200:E36-E51. [DOI: 10.1086/720206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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75
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Furey GN, Hawthorne PL, Tilman D. Might field experiments also be inadvertent metacommunities? Ecology 2022; 103:e3694. [PMID: 35353386 DOI: 10.1002/ecy.3694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/15/2021] [Accepted: 12/29/2021] [Indexed: 11/10/2022]
Abstract
Metacommunity theory predicts that the composition and diversity of a site depends on its characteristics and those of its neighborhood. Dispersal between plots in a field experiment could link responses observed in a focal plot to both its treatment and those of its neighbors. However, the diversity, composition and treatments of neighboring plots are rarely included in analyses of experimental treatments. We analyzed a spatially gridded grassland nitrogen addition experiment and found that plant species richness and the composition of focal plots were influenced not just by their nitrogen treatment but also by the number of species in neighboring plots and their abundances. For each additional species in a focal plot's neighborhood, the species richness of the focal plot increased by 0.30 species per 0.3 m2 . Control plots had a significant loss of species, at a rate of ~0.23 species per 0.3 m2 per year during the 23-year experiment, but only when their neighborhoods had low species richness. Changes in the abundance of the three dominant species depended both on the nitrogen treatment of a focal plot and on their abundance in adjacent plots. Our analyses suggested that both the experimental nitrogen treatments and metacommunity processes co-determined plant species richness and plant species' abundances. Our findings suggested that analyzing many traditional field experiments with a metacommunity perspective may reveal confounding of experimental treatments and provide empirical data to test metacommunity theory.
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Affiliation(s)
- George N Furey
- Ecology Evolution and Behavior, College of Biological Science, University of Minnesota, St. Paul, MN
| | - Peter L Hawthorne
- Institute on the Environment, University of Minnesota, Saint Paul, MN
| | - David Tilman
- Bren School of Environmental Management, University of California Santa Barbara, Santa Barbara, CA
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76
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Assessing the roles of nitrogen, biomass, and niche dimensionality as drivers of species loss in grassland communities. Proc Natl Acad Sci U S A 2022; 119:e2112010119. [PMID: 35235460 PMCID: PMC8915794 DOI: 10.1073/pnas.2112010119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Nutrient enrichment of natural ecosystems is a primary characteristic of the Anthropocene and a known cause of biodiversity loss, particularly in grasslands. In a global meta-analysis of 630 resource addition experiments, we conduct a simultaneous test of the three most prominent explanations of this phenomenon. Our results conclusively indicate that nitrogen is the leading cause of species loss. This result is important because of the increase in nitrogen deposition and the frequent use of nitrogen-based fertilizers worldwide. Our findings provide global-scale, experimental evidence that minimizing nitrogen inputs to ecological systems may help to conserve the diversity of grassland ecosystems. Eutrophication is a major driver of species loss in plant communities worldwide. However, the underlying mechanisms of this phenomenon are controversial. Previous studies have raised three main explanations: 1) High levels of soil resources increase standing biomass, thereby intensifying competitive interactions (the “biomass-driven competition hypothesis”). 2) High levels of soil resources reduce the potential for resource-based niche partitioning (the “niche dimension hypothesis”). 3) Increasing soil nitrogen causes stress by changing the abiotic or biotic conditions (the “nitrogen detriment hypothesis”). Despite several syntheses of resource addition experiments, so far, no study has tested all of the hypotheses together. This is a major shortcoming, since the mechanisms underlying the three hypotheses are not independent. Here, we conduct a simultaneous test of the three hypotheses by integrating data from 630 resource addition experiments located in 99 sites worldwide. Our results provide strong support for the nitrogen detriment hypothesis, weaker support for the biomass-driven competition hypothesis, and negligible support for the niche dimension hypothesis. The results further show that the indirect effect of nitrogen through its effect on biomass is minor compared to its direct effect and is much larger than that of all other resources (phosphorus, potassium, and water). Thus, we conclude that nitrogen-specific mechanisms are more important than biomass or niche dimensionality as drivers of species loss under high levels of soil resources. This conclusion is highly relevant for future attempts to reduce biodiversity loss caused by global eutrophication.
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77
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Shen H, Dong S, DiTommaso A, Xiao J, Lu W, Zhi Y. Nitrogen Deposition Shifts Grassland Communities Through Directly Increasing Dominance of Graminoids: A 3-Year Case Study From the Qinghai-Tibetan Plateau. FRONTIERS IN PLANT SCIENCE 2022; 13:811970. [PMID: 35317015 PMCID: PMC8934429 DOI: 10.3389/fpls.2022.811970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/18/2022] [Indexed: 05/25/2023]
Abstract
Nitrogen (N) deposition has been increasing for decades and has profoundly influenced the structure and function of grassland ecosystems in many regions of the world. However, the impact of N deposition on alpine grasslands is less well documented. We conducted a 3-year field experiment to determine the effects of N deposition on plant species richness, composition, and community productivity in an alpine meadow of the Qinghai-Tibetan Plateau of China. We found that 3 years of N deposition had a profound effect on these plant community parameters. Increasing N rates increased the dominance of graminoids and reduced the presence of non-graminoids. Species richness was inversely associated with aboveground biomass. The shift in plant species and functional group composition was largely responsible for the increase in productivity associated with N deposition. Climatic factors also interacted with N addition to influence productivity. Our findings suggest that short-term N deposition could increase the productivity of alpine meadows through shifts in composition toward a graminoid-dominated community. Longer-term studies are needed to determine if shifts in composition and increased productivity will be maintained. Future work must also evaluate whether decreasing plant diversity will impair the long-term stability and function of sensitive alpine grasslands.
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Affiliation(s)
- Hao Shen
- School of Grassland Science, Beijing Forestry University, Beijing, China
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing, China
- Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Shikui Dong
- School of Grassland Science, Beijing Forestry University, Beijing, China
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing, China
- Department of Natural Resources, Cornell University, Ithaca, NY, United States
| | - Antonio DiTommaso
- Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Jiannan Xiao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing, China
| | - Wen Lu
- Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolia Plateau, Collaborative Innovation Center for Grassland Ecological Security, College of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Yangliu Zhi
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing, China
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78
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Zi H, Hu L, Wang C. Differentiate Responses of Soil Microbial Community and Enzyme Activities to Nitrogen and Phosphorus Addition Rates in an Alpine Meadow. FRONTIERS IN PLANT SCIENCE 2022; 13:829381. [PMID: 35310625 PMCID: PMC8924503 DOI: 10.3389/fpls.2022.829381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
Nitrogen (N) and phosphorus (P) are the dominant limiting nutrients in alpine meadows, but it is relatively unclear how they affect the soil microbial community and whether their effects are rate dependent. Here, N and P addition rates (0, 10, 20, and 30 g m-2 year-1) were evaluated in an alpine meadow and variables related to plants and soils were measured to determine the processes affecting soil microbial community and enzyme activities. Our results showed that soil microbial biomass, including bacteria, fungi, gramme-negative bacteria, and actinomycetes, decreased along with N addition rates, but they first decreased at low P addition rates (10 g m-2 year-1) and then significantly increased at high P addition rates (30 g m-2 year-1). Both the N and P addition stimulated soil invertase activity, while urease and phosphatase activities were inhibited at low N addition rate and then increased at high N addition rate. P addition generally inhibited peroxidase and urease activities, but increased phosphatase activity. N addition decreased soil pH and, thus, inhibited soil microbial microorganisms, while P addition effects were unimodal with addition rates, achieved through altering sedge, and available P in the soil. In conclusion, our studies indicated that soil microbial communities and enzyme activities are sensitive to short-term N and P addition and are also significantly influenced by their addition rates.
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Affiliation(s)
- Hongbiao Zi
- State Key Laboratory of Grassland Agro-Ecosystems, and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Lei Hu
- Institute of Qinghai-Tibetan Plateau Research, Southwest Minzu University, Chengdu, China
| | - Changting Wang
- Institute of Qinghai-Tibetan Plateau Research, Southwest Minzu University, Chengdu, China
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79
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Sun L, Yang G, Zhang Y, Qin S, Dong J, Cui Y, Liu X, Zheng P, Wang R. Leaf Functional Traits of Two Species Affected by Nitrogen Addition Rate and Period Not Nitrogen Compound Type in a Meadow Grassland. FRONTIERS IN PLANT SCIENCE 2022; 13:841464. [PMID: 35295632 PMCID: PMC8918929 DOI: 10.3389/fpls.2022.841464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
Plasticity of plant functional traits plays an important role in plant growth and survival under changing climate. However, knowledge about how leaf functional traits respond to the multi-level N addition rates, multiple N compound and duration of N application remains lacking. This study investigated the effects of 2-year and 7-year N addition on the leaf functional traits of Leymus chinensis and Thermopsis lanceolata in a meadow grassland. The results showed that the type of N compounds had no significant effect on leaf functional traits regardless of duration of N application. N addition significantly increased the leaf total N content (LN) and specific leaf area (SLA), and decreased the leaf total P content (LP) and leaf dry matter content (LDMC) of the two species. Compared with short-term N addition, long-term N addition increased LN, LP, SLA, and plant height, but decreased the LDMC. In addition, the traits of the two species were differentially responsive to N addition, LN and LP of T. lanceolata were consistently higher than those of L. chinensis. N addition would make L. chinensis and T. lanceolata tend to "quick investment-return" strategy. Our results provide more robust and comprehensive predictions of the effects of N deposition on leaf traits.
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Affiliation(s)
- Lu Sun
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Qingdao, China
| | - Guojiao Yang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- College of Ecology and Environment, Hainan University, Haikou, China
| | - Yang Zhang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Qingdao, China
| | - Siqi Qin
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Qingdao, China
| | - Jibin Dong
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Qingdao, China
| | - Yangzhe Cui
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Qingdao, China
| | - Xiao Liu
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Qingdao, China
| | - Peiming Zheng
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Qingdao, China
| | - Renqing Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Jinan, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Jinan, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Qingdao, China
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80
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Zettlemoyer MA. Leaf traits mediate herbivory across a nitrogen gradient differently in extirpated vs. extant prairie species. Oecologia 2022; 198:711-720. [PMID: 35192065 DOI: 10.1007/s00442-022-05130-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 01/28/2022] [Indexed: 10/19/2022]
Abstract
Increasing nitrogen deposition threatens many grassland species with local extinction. In addition to the direct effects of nitrogen deposition, nitrogen can indirectly affect plant populations via phenotypic shifts in plant traits that influence plant susceptibility to herbivory. Here, I test how herbivory varies across an experimental nitrogen gradient and whether differences in susceptibility to herbivory might explain patterns of local species loss. Specifically, I examine how increasing nitrogen availability in a restored prairie influences leaf traits and subsequent herbivory (by leaf-chewers like insects/small mammals versus deer) and the severity of herbivore damage on confamiliar pairs of extirpated versus extant species from Michigan prairies. Nitrogen increased herbivory by both leaf-chewers and deer as well as herbivore damage (proportion of leaves damaged). Leaf hairiness and specific leaf area affected patterns of herbivory following nitrogen addition, although patterns varied between extirpated vs. extant taxa and herbivory type. Nitrogen increased leaf hairiness. At high levels of nitrogen addition, hairy extant plants experienced less herbivory and damage than smooth-leaved plants. In contrast, hairy extirpated plants were more likely to experience leaf-chewer herbivory. Extirpated plants with thin leaves (high specific leaf area) were less likely to experience leaf-chewer herbivory; the opposite was true for extant species. Generally, extant species experienced more herbivory than locally extirpated species, particularly at high levels of nitrogen addition, suggesting that increasing herbivory under nutrient addition likely does not influence extirpation in this system. This study suggests that trait-mediated responses to nitrogen addition and herbivory differ between extant and extirpated species.
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Affiliation(s)
- Meredith A Zettlemoyer
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI, 49060-9505, USA. .,Department of Plant Biology, University of Georgia, Athens, GA, 30602-5004, USA.
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81
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Li S, Zhao Z, Dong S, Shen H, Xu Y, Xiao J, Gao X, Wu S, Stufkens P. Synchronous Responses of Plant Functional Traits to Nitrogen Deposition From Dominant Species to Functional Groups and Whole Communities in Alpine Grasslands on the Qinghai-Tibetan Plateau. FRONTIERS IN PLANT SCIENCE 2022; 13:827035. [PMID: 35222485 PMCID: PMC8864091 DOI: 10.3389/fpls.2022.827035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/11/2022] [Indexed: 05/25/2023]
Abstract
Nitrogen deposition is recognized as one of the major threats to the ecosystem function of alpine grasslands on the Qinghai-Tibetan Plateau (QTP). However, few studies have documented the gradient responses of plant species, functional groups, and communities in alpine grassland ecosystems to various levels of N deposition on the QTP. We applied eight linear mixed-effect models combing acidification, eutrophication, and phosphorus availability to explore if the responses of functional traits (particularly plant height and specific leaf area) of plants from dominant species to functional groups and whole communities in different types of grassland to nitrogen deposition were consistent with the same or different models. We found that the specific leaf area of Stipa capillata, non-forb, and community-weighted mean value in the alpine steppe were synchronous and related to acidification with nitrogen addition; the height of Stipa capillata, non-forb, and community-weighted mean value in the alpine steppe was synchronous and related to acidification, eutrophication, and phosphorus availability with nitrogen addition; the height and specific leaf area of Elymus breviaristatus to functional groups and community-weighted mean value in cultivated grasslands (CGs) were synchronous and related to acidification, eutrophication, and phosphorus availability with nitrogen addition. Most of the responses of functional traits of plants to acidification, eutrophication, and phosphorus availability associated with nitrogen deposition in the alpine steppe and the CG were synchronous, while only the response of the specific leaf area of forb functional groups to eutrophication associated with N deposition in the alpine steppe was asynchronous.
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Affiliation(s)
- Shuai Li
- College of Resource and Environment, Shanxi Agricultural University, Jinzhong, China
| | - Zhenzhen Zhao
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, China
| | - Shikui Dong
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Hao Shen
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Yudan Xu
- College of Grassland Science, Shanxi Agricultural University, Jinzhong, China
| | - Jiannan Xiao
- School of Environment, Beijing Normal University, Beijing, China
| | - Xiaoxia Gao
- School of Environment, Beijing Normal University, Beijing, China
| | - Shengnan Wu
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Paul Stufkens
- English Department, Zamorano University, Tegucigalpa, Honduras
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82
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Li M, Wang L, Li J, Peng Z, Wang L, Zhang X, Xu S. Grazing exclusion had greater effects than nitrogen addition on soil and plant community in a desert steppe, Northwest of China. BMC PLANT BIOLOGY 2022; 22:60. [PMID: 35114932 PMCID: PMC8812004 DOI: 10.1186/s12870-021-03400-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND The impacts of increasing nitrogen (N) deposition and overgrazing on terrestrial ecosystems have been continuously hot issues. Grazing exclusion, aimed at restoration of grassland ecosystem function and service, has been extensively applied, and considered a rapid and effective vegetation restoration method. However, the synthetic effects of exclosure and N deposition on plant and community characteristics have rarely been studied. Here, a 4-year field experiment of N addition and exclusion treatment had been conducted in the desert steppe dominated by Alhagi sparsifolia and Lycium ruthenicum in northwest of China, and the responses of soil characteristics, plant nutrition and plant community to the treatments had been analyzed. RESULTS The grazing exclusion significantly increased total N concentration in the surface soil (0-20 cm), and increased plant height, coverage (P < 0.05) and aboveground biomass. Specifically, A. sparsifolia recovered faster both in individual and community levels than L. ruthenicum did after exclusion. There was no difference in response to N addition gradients between the two plants. CONCLUSIONS Our findings suggest that it is exclusion rather than N addition that has greater impacts on soil properties and plant community in desert steppe. Present N deposition level has no effect on plant community of desert steppe based on short-term experimental treatments.
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Affiliation(s)
- Mengru Li
- School of Life Sciences, Lanzhou University, No. 222, Southern Tianshui Road, Lanzhou, 730000, China
| | - Lilong Wang
- School of Life Sciences, Lanzhou University, No. 222, Southern Tianshui Road, Lanzhou, 730000, China
- Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou, 730000, China
| | - Junjun Li
- School of Life Sciences, Lanzhou University, No. 222, Southern Tianshui Road, Lanzhou, 730000, China
| | - Zhenling Peng
- School of Life Sciences, Lanzhou University, No. 222, Southern Tianshui Road, Lanzhou, 730000, China
| | - Liang Wang
- Administration of Anxi Extra-arid Desert National Nature Reserve, Guazhou, 736100, China
| | - Xinfang Zhang
- School of Life Sciences, Lanzhou University, No. 222, Southern Tianshui Road, Lanzhou, 730000, China
| | - Shijian Xu
- School of Life Sciences, Lanzhou University, No. 222, Southern Tianshui Road, Lanzhou, 730000, China.
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83
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Liu H, Yin H, Kong F, Middel A, Zheng X, Huang J, Sun T, Wang D, Lensky IM. Change of nutrients, microorganisms, and physical properties of exposed extensive green roof substrate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 805:150344. [PMID: 34818784 DOI: 10.1016/j.scitotenv.2021.150344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 09/10/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
Green roofs (GR) can be used as a nature-based solution to tackle eco-environmental problems caused by climate change and rapid urbanization. The substrate in the GRs is the growing medium for vegetation, and its properties directly affect the ecosystem services of GRs. To investigate the characteristic changes of an exposed substrate after the removal of vegetation, a one-year field experiment was conducted. Substrate properties were comprehensively compared for areas in GR that were planted with Sedum lineare and those with bare substrate. Results show that vegetation cover not only prevented substrate loss by 5.14% (p < 0.05) but also protected the chemical, microbial, and physical properties of the substrate. Moreover, the structure of the substrate changed, as evidenced by a significant increase in fine sand (p < 0.05). The results highlight that attention should be paid to maintaining vegetation cover during GR management. In addition, extensive GRs may not be suitable for fallowing. Once a GR has been established, it needs regular maintenance. Otherwise, the ecological and economic benefits of the GR may be reduced. The findings of the present study can be used to determine the life-cycle costs. Further research should focus on differences in the substrate loss rates, runoff, and temperatures of the substrates under exposure and vegetation cover. The microbial changes after revegetation should also be studied to clarify the role of vegetation in GR ecosystems. The present study provides a reference for improving GR management and ensuring their sustainability.
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Affiliation(s)
- Hongqing Liu
- School of Geography and Ocean Science, Nanjing University, Xianlin Ave. 163, 210023 Nanjing, China
| | - Haiwei Yin
- School of Architecture and Urban Planning, Nanjing University, No. 22, Hankou Road, 210093 Nanjing, China
| | - Fanhua Kong
- School of Geography and Ocean Science, Nanjing University, Xianlin Ave. 163, 210023 Nanjing, China.
| | - Ariane Middel
- School of Arts, Media and Engineering, Arizona State University, 950 S. Forest Mall, Stauffer B258, 85281 Tempe, AZ, USA
| | - Xiandi Zheng
- School of Geography and Ocean Science, Nanjing University, Xianlin Ave. 163, 210023 Nanjing, China
| | - Jing Huang
- School of Geography and Ocean Science, Nanjing University, Xianlin Ave. 163, 210023 Nanjing, China
| | - Tao Sun
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ding Wang
- School of Geography and Ocean Science, Nanjing University, Xianlin Ave. 163, 210023 Nanjing, China
| | - Itamar M Lensky
- Department of Geography and Environment, Bar-Ilan University, 5290002 Ramat-Gan, Israel
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84
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Liu Y, Liu B, Yue Z, Zeng F, Li X, Li L. Effects of short-term nitrogen and phosphorus addition on leaf stoichiometry of a dominant alpine grass. PeerJ 2022; 9:e12611. [PMID: 35036130 PMCID: PMC8710051 DOI: 10.7717/peerj.12611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/18/2021] [Indexed: 11/28/2022] Open
Abstract
The effects of increasing nitrogen (N) and phosphorus (P) deposition on the nutrient stoichiometry of soil and plant are gaining improving recognition. However, whether and how the responses of N cycle coupled with P of the soil–plant system to external N and P deposition in alpine grassland is still unclear. A short-term external N and P addition experiment was conducted in an alpine grazing grassland in the KunLun Mountain to explore the effects of short-term N and P addition on the nutrient stoichiometry in soil and plant. Different rates of N addition (ranging from 0.5 g N m−2 yr−1 to 24 g N m−2 yr−1) and P addition (ranging from 0.05 g N m−2 yr−1 to 3.2 g P m−2 yr−1) were supplied, and the soil available N, P, leaf N and P stoichiometry of Seriphidium rhodanthum which dominant in the alpine ecosystem were measured. Results showed that N addition increased soil inorganic N, leaf C, leaf N, and leaf N:P ratio but decreased soil available P and leaf C:P. Furthermore, P addition increased soil available P, leaf P, soil inorganic N, leaf N, and leaf C and reduced leaf C:N, C:P, and N:P ratios. Leaf N:P was positively related to N addition gradient. Leaf C:P and leaf N:P were significantly negatively related to P addition gradient. Although external N and P addition changed the value of leaf N:P, the ratio was always lower than 16 in all treatments. The influences of P addition on soil and plant mainly caused the increase in soil available P concentration. In addition, the N and P cycles in the soil–plant system were tightly coupled in P addition but decoupled in N addition condition. The nutrient stoichiometry of soil and leaf responded differently to continuous N and P addition gradients. These data suggested that the alpine grazing grassland was limited by P rather than N due to long-term N deposition and uniform fertilization. Moreover, increasing P addition alleviated P limitation. Therefore, the imbalanced N and P input could change the strategy of nutrient use of the grass and then change the rates of nutrient cycling in the alpine grassland ecosystem in the future.
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Affiliation(s)
- YaLan Liu
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.,Cele National Station of Observation and Research for Desert-Grassland Ecosystem in Xinjiang, Cele, Xinjiang, China.,State Key Laboratory of Desert and Oasis Ecology, Chinese Academy of Sciences, Urumqi, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Bo Liu
- Shandong Provincial Key Lab. of Soil Conservation and Environmental Protection, College of Resources and Environment, Linyi University, Linyi, China
| | - Zewei Yue
- University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Fanjiang Zeng
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.,Cele National Station of Observation and Research for Desert-Grassland Ecosystem in Xinjiang, Cele, Xinjiang, China.,State Key Laboratory of Desert and Oasis Ecology, Chinese Academy of Sciences, Urumqi, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xiangyi Li
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.,Cele National Station of Observation and Research for Desert-Grassland Ecosystem in Xinjiang, Cele, Xinjiang, China.,State Key Laboratory of Desert and Oasis Ecology, Chinese Academy of Sciences, Urumqi, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lei Li
- Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.,Cele National Station of Observation and Research for Desert-Grassland Ecosystem in Xinjiang, Cele, Xinjiang, China.,State Key Laboratory of Desert and Oasis Ecology, Chinese Academy of Sciences, Urumqi, China.,University of Chinese Academy of Sciences, Beijing, China
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85
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Liu M, Zhu L, Ma Y, Zhang Y, Xu L, Wang M, Liu C. Response of species abundance distribution pattern of alpine meadow community to sampling scales. RANGELAND JOURNAL 2022. [DOI: 10.1071/rj21034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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86
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Easterday CA, Kendig AE, Lacroix C, Seabloom EW, Borer ET. Long-term nitrogen enrichment mediates the effects of nitrogen supply and co-inoculation on a viral pathogen. Ecol Evol 2022; 12:e8450. [PMID: 35136545 PMCID: PMC8809429 DOI: 10.1002/ece3.8450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/02/2021] [Accepted: 11/05/2021] [Indexed: 11/12/2022] Open
Abstract
Host nutrient supply can mediate host-pathogen and pathogen-pathogen interactions. In terrestrial systems, plant nutrient supply is mediated by soil microbes, suggesting a potential role of soil microbes in plant diseases beyond soil-borne pathogens and induced plant defenses. Long-term nitrogen (N) enrichment can shift pathogenic and nonpathogenic soil microbial community composition and function, but it is unclear if these shifts affect plant-pathogen and pathogen-pathogen interactions. In a growth chamber experiment, we tested the effect of long-term N enrichment on infection by Barley Yellow Dwarf Virus (BYDV-PAV) and Cereal Yellow Dwarf Virus (CYDV-RPV), aphid-vectored RNA viruses, in a grass host. We inoculated sterilized growing medium with soil collected from a long-term N enrichment experiment (ambient, low, and high N soil treatments) to isolate effects mediated by the soil microbial community. We crossed soil treatments with a N supply treatment (low, high) and virus inoculation treatment (mock-, singly-, and co-inoculated) to evaluate the effects of long-term N enrichment on plant-pathogen and pathogen-pathogen interactions, as mediated by N availability. We measured the proportion of plants infected (i.e., incidence), plant biomass, and leaf chlorophyll content. BYDV-PAV incidence (0.96) declined with low N soil (to 0.46), high N supply (to 0.61), and co-inoculation (to 0.32). Low N soil mediated the effect of N supply on BYDV-PAV: instead of N supply reducing BYDV-PAV incidence, the incidence increased. Additionally, ambient and low N soil ameliorated the negative effect of co-inoculation on BYDV-PAV incidence. BYDV-PAV infection only reduced chlorophyll when plants were grown with low N supply and ambient N soil. There were no significant effects of long-term N soil on CYDV-RPV incidence. Soil inoculant with different levels of long-term N enrichment had different effects on host-pathogen and pathogen-pathogen interactions, suggesting that shifts in soil microbial communities with long-term N enrichment may mediate disease dynamics.
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Affiliation(s)
- Casey A. Easterday
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
- Present address:
Carlson School of ManagementUniversity of MinnesotaMinneapolisMinnesotaUSA
| | - Amy E. Kendig
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Christelle Lacroix
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
- Present address:
Pathologie VégétaleINRAEMontfavetFrance
| | - Eric W. Seabloom
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Elizabeth T. Borer
- Department of Ecology, Evolution, and BehaviorUniversity of MinnesotaSt. PaulMinnesotaUSA
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87
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Zheng S, Chi Y, Yang X, Li W, Lan Z, Bai Y. Direct and indirect effects of nitrogen enrichment and grazing on grassland productivity through intraspecific trait variability. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.14078] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shuxia Zheng
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China
| | - Yonggang Chi
- College of Geography and Environmental Sciences Zhejiang Normal University Jinhua China
| | - Xiaojing Yang
- School of Geography and Tourism Shaanxi Normal University Xi'an China
| | - Wenhuai Li
- School of Ecology and Environment Inner Mongolia University Hohhot China
| | - Zhichun Lan
- Observation and Research Station for the Wetland Ecosystem of Lake Poyang Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Lushan China
| | - Yongfei Bai
- State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing China
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88
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Terrestrial Nitrogen Inputs Affect the Export of Unprocessed Atmospheric Nitrate to Surface Waters: Insights from Triple Oxygen Isotopes of Nitrate. Ecosystems 2021. [DOI: 10.1007/s10021-021-00722-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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89
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Chen X, Wei H, Zhang J. Nitrogen and Sulfur Additions Improved the Diversity of nirK- and nirS-Type Denitrifying Bacterial Communities of Farmland Soil. BIOLOGY 2021; 10:biology10111191. [PMID: 34827184 PMCID: PMC8615190 DOI: 10.3390/biology10111191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/06/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Anthropogenic nitrogen (N) and sulfur (S) deposition can change above- and belowground biodiversity, including soil microbial diversity. The diversity of denitrifying microorganisms is of great significance to the calculation of the global nitrogen cycle and nitrogen flux. For a long time, nirK and nirS have been used as the functional genes to study denitrifying microorganisms, and have gradually become molecular markers for studying the composition and diversity of denitrifying bacteria. Here, three-time exposures to N and S applications (7, 30, and 60 days), were independently established. Additionally, the abundance, diversity, and structure of nirK- and nirS-type denitrifying communities were examined by sequencing analyses in response to three treatments, namely, N and S (TN/S), sodium chloride (TNaCl) and deionized water (pH = 7.0) (CK). Our results suggest that TN/S led to higher electrical conductivity (EC), total nitrogen (TN), total organic carbon (TOC), nitrate nitrogen (NO3--N), ammonium nitrogen (NH4+-N), and lower pH compared with TNaCl and CK, which affected the diversity of nirK- and nirS-type denitrifying bacterial communities. We also observed that the nirK-type denitrifying community demonstrated a higher sensitivity to N and S additions. Overall, our results are important for the understanding of nitrogen in soil and N2O emissions.
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Affiliation(s)
- Xuan Chen
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; (X.C.); (H.W.)
| | - Hui Wei
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; (X.C.); (H.W.)
- Guangdong Engineering Research Center for Modern Eco-Agriculture and Circular Agriculture, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, China
| | - Jiaen Zhang
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; (X.C.); (H.W.)
- Guangdong Engineering Research Center for Modern Eco-Agriculture and Circular Agriculture, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
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90
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Plant Community Diversity at Two Reclaimed Mine Tailing Storage Facilities in Québec, Canada. LAND 2021. [DOI: 10.3390/land10111191] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mining activities generate residues during the ore concentration process. These wastes are placed into large tailing storage facilities, and upon mine closure, these tailings must be reclaimed. This study aimed to determine how different reclamation methods, involving combinations of planted boreal woody species and organic amendments application (paper mill sludge biosolids, chicken manure, and topsoil) affected plant community diversity at two tailing storage facilities in Québec, Canada. We recorded the composition of the plant communities using the percent cover of plant species within 1 m × 1 m quadrats. At the Niobec mine site, paper mill sludge mixed with topsoil enhanced total plant cover was compared with the use of topsoil only; the former amendment, however, reduced evenness (J′) and diversity (1−D) due to the increased growth of grasses and invasive forbs. At the Mont-Wright site, plots having received paper mill sludge mixed with a “Norco” treatment (a mixture of chicken manure, hay, and grass seeds) produced the highest total plant cover. The Norco treatment mixed with topsoil and the single application of topsoil and biosolids produced the highest evenness (J′) and diversity (1−D). Overall, organic amendment applications promoted vegetation cover on tailings and contributed to the colonization of diverse plant communities.
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91
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Barros-Rodríguez A, Rangseekaew P, Lasudee K, Pathom-aree W, Manzanera M. Impacts of Agriculture on the Environment and Soil Microbial Biodiversity. PLANTS 2021; 10:plants10112325. [PMID: 34834690 PMCID: PMC8619008 DOI: 10.3390/plants10112325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/13/2021] [Accepted: 10/25/2021] [Indexed: 11/16/2022]
Abstract
Agriculture represents an important mechanism in terms of reducing plant, animal, and microbial biodiversity and altering the environment. The pressure to cope with the increasing food demands of the human population has intensified the environmental impact, and alternative ways to produce food are required in order to minimize the decrease in biodiversity. Conventional agricultural practices, such as floods and irrigation systems; the removal of undesired vegetation by fires, tilling, and plowing; the use of herbicides, fertilizers, and pesticides; and the intensification of these practices over the last 50 years, have led to one of the most important environmental threats—a major loss of biodiversity. In this study, we review the impact that agriculture and its intensification have had on the environment and biodiversity since its invention. Moreover, we demonstrate how these impacts could be reduced through the use of microorganisms as biostimulants.
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Affiliation(s)
| | - Pharada Rangseekaew
- Doctor of Philosophy Program in Applied Microbiology (International Program), Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
- Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Krisana Lasudee
- Research Center of Excellence in Bioresources for Agriculture, Industry and Medicine, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; (K.L.); (W.P.-a.)
| | - Wasu Pathom-aree
- Research Center of Excellence in Bioresources for Agriculture, Industry and Medicine, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; (K.L.); (W.P.-a.)
| | - Maximino Manzanera
- Department of Microbiology, Institute for Water Research, University of Granada, 18071 Granada, Spain;
- Correspondence: ; Tel.: +34-958-248324; Fax: +34-958-243094
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92
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Sensitive Groups of Bacteria Dictate Microbial Functional Responses to Short-term Warming and N Input in a Semiarid Grassland. Ecosystems 2021. [DOI: 10.1007/s10021-021-00719-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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93
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Zhang Y, Ren Z, Zhang Y. Winter nitrogen enrichment does not alter the sensitivity of plant communities to precipitation in a semiarid grassland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 790:148264. [PMID: 34380248 DOI: 10.1016/j.scitotenv.2021.148264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 06/13/2023]
Abstract
Nitrogen (N) deposition often promotes aboveground net primary productivity (ANPP), but has adverse effects on terrestrial ecosystem biodiversity. It is unclear, however, whether biomass production and biodiversity are equally altered by seasonal N enrichment, as there is a temporal pattern to atmospheric N deposition. By adding N in autumn, winter, or growing season from October 2014 to May 2019 in a temperate grassland in China, we found that N addition promoted peak plant community ANPP, but tended to decrease plant richness. Regardless of seasonal N additions, precipitation was positively correlated with plant community ANPP, confirming that precipitation is the primary limiting factor in this semiarid grassland. Unexpectedly, N addition in autumn or growing season, but not in winter, increased the sensitivity of plant communities to precipitation (i.e., the slope of the positive relationship between community ANPP and precipitation), indicating that precipitation determines the influence of seasonal N enrichment on plant community biomass production. These findings suggest that previous studies in which N was added in a single season, e.g., the growing season, have likely overestimated the effects of N deposition on ecosystem primary productivity, especially during wet years. This study illustrates that multi-season N addition in agreement with predicted seasonal patterns of N deposition needs to be evaluated to precisely assess ecosystem responses.
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Affiliation(s)
- Yuqiu Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Yuquan Road, Beijing 100049, China
| | - Zhengru Ren
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Yuquan Road, Beijing 100049, China
| | - Yunhai Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Yuquan Road, Beijing 100049, China.
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94
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He Y, Xu R, Prior SA, Yang D, Yang A, Chen J. Satellite-detected ammonia changes in the United States: Natural or anthropogenic impacts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 789:147899. [PMID: 34323822 DOI: 10.1016/j.scitotenv.2021.147899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 05/06/2021] [Accepted: 05/17/2021] [Indexed: 06/13/2023]
Abstract
Ammonia (NH3) is the most abundant alkaline component and can react with atmospheric acidic species to form aerosols that can lead to numerous environmental and health issues. Increasing atmospheric NH3 over agricultural regions in the US has been documented. However, spatiotemporal changes of NH3 concentrations over the entire US are still not thoroughly understood, and the factors that drive these changes remain unknown. Herein, we applied the Atmospheric Infrared Sounder (AIRS) monthly NH3 dataset to explore spatiotemporal changes in atmospheric NH3 and the empirical relationships with synthetic N fertilizer application, livestock manure production, and climate factors across the entire US at both regional and pixel levels from 2002 to 2016. We found that, in addition to the US Midwest, the Mid-South and Western regions also experienced striking increases in NH3 concentrations. NH3 released from livestock manure during warmer winters contributed to increased annual NH3 concentrations in the Western US. The influence of temperature on temporal evolution of NH3 concentrations was associated with synthetic N fertilizer use in the Northern Great Plains. With a strong positive impact of temperature on NH3 concentrations in the US Midwest, this region could possibly become an atmospheric NH3 hotspot in the context of future warming. Our study provides an essential scientific basis for US policy makers in developing mitigation strategies for agricultural NH3 emissions under future climate change scenarios.
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Affiliation(s)
- Yaqian He
- Department of Geography, University of Central Arkansas, Conway, AR, USA
| | - Rongting Xu
- Forest Ecosystems and Society, Oregon State University, Corvallis, OR, USA.
| | | | - Di Yang
- Wyoming Geographic Information Center, University of Wyoming, Laramie, WY, USA
| | - Anni Yang
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, USA; National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, CO, USA
| | - Jian Chen
- Department of Computer Science and Software Engineering, Samuel Ginn College of Engineering, Auburn University, Auburn, AL, USA
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95
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Seabloom EW, Borer ET, Hobbie SE, MacDougall AS. Soil nutrients increase long-term soil carbon gains threefold on retired farmland. GLOBAL CHANGE BIOLOGY 2021; 27:4909-4920. [PMID: 34311496 DOI: 10.1111/gcb.15778] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/27/2021] [Accepted: 06/27/2021] [Indexed: 06/13/2023]
Abstract
Abandoned agricultural lands often accumulate soil carbon (C) following depletion of soil C by cultivation. The potential for this recovery to provide significant C storage benefits depends on the rate of soil C accumulation, which, in turn, may depend on nutrient supply rates. We tracked soil C for almost four decades following intensive agricultural soil disturbance along an experimentally imposed gradient in nitrogen (N) added annually in combination with other macro- and micro-nutrients. Soil %C accumulated over the course of the study in unfertilized control plots leading to a gain of 6.1 Mg C ha-1 in the top 20 cm of soil. Nutrient addition increased soil %C accumulation leading to a gain of 17.8 Mg C ha-1 in fertilized plots, nearly a threefold increase over the control plots. These results demonstrate that substantial increases in soil C in successional grasslands following agricultural abandonment occur over decadal timescales, and that C gain is increased by high supply rates of soil nutrients. In addition, soil %C continued to increase for decades under elevated nutrient supply, suggesting that short-term nutrient addition experiments underestimate the effects of soil nutrients on soil C accumulation.
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Affiliation(s)
- Eric W Seabloom
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, USA
| | - Elizabeth T Borer
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, USA
| | - Sarah E Hobbie
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, USA
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96
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Kimmel K, Dee LE, Avolio ML, Ferraro PJ. Causal assumptions and causal inference in ecological experiments. Trends Ecol Evol 2021; 36:1141-1152. [PMID: 34538502 DOI: 10.1016/j.tree.2021.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/10/2021] [Accepted: 08/16/2021] [Indexed: 11/29/2022]
Abstract
Causal inferences from experimental data are often justified based on treatment randomization. However, inferring causality from data also requires complementary causal assumptions, which have been formalized by scholars of causality but not widely discussed in ecology. While ecologists have recognized challenges to inferring causal relationships in experiments and developed solutions, they lack a general framework to identify and address them. We review four assumptions required to infer causality from experiments and provide design-based and statistically based solutions for when these assumptions are violated. We conclude that there is no clear demarcation between experimental and non-experimental designs. This insight can help ecologists design better experiments and remove barriers between experimental and observational scholarship in ecology.
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Affiliation(s)
- Kaitlin Kimmel
- Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Laura E Dee
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, USA.
| | - Meghan L Avolio
- Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Paul J Ferraro
- Carey Business School, Johns Hopkins University, Baltimore, MD, USA; Department of Environmental Health and Engineering, a joint department of the Bloomberg School of Public Health and the Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA.
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97
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Kazanski CE, Cowles J, Dymond S, Clark AT, David AS, Jungers JM, Kendig AE, Riggs CE, Trost J, Wei X. Water availability modifies productivity response to biodiversity and nitrogen in long-term grassland experiments. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02363. [PMID: 33899307 DOI: 10.1002/eap.2363] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/15/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Diversity and nitrogen addition have positive relationships with plant productivity, yet climate-induced changes in water availability threaten to upend these established relationships. Using long-term data from three experiments in a mesic grassland (ranging from 17 to 34 yr of data), we tested how the effects of species richness and nitrogen addition on community-level plant productivity changed as a function of annual fluctuations in water availability using growing season precipitation and the Standardized Precipitation-Evapotranspiration Index (SPEI). While results varied across experiments, our findings demonstrate that water availability can magnify the positive effects of both biodiversity and nitrogen addition on productivity. These results suggest that productivity responses to anthropogenic species diversity loss and increasing nitrogen deposition could depend on precipitation regimes, highlighting the importance of testing interactions between multiple global change drivers.
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Affiliation(s)
- Clare E Kazanski
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota, 55108, USA
- The Nature Conservancy, 1101 West River Parkway, Minneapolis, Minnesota, 55415, USA
| | - Jane Cowles
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota, 55108, USA
| | - Salli Dymond
- Departments of Forestry Resources, University of Minnesota, St. Paul, Minnesota, 55108, USA
- Department of Earth and Environmental Sciences, University of Minnesota-Duluth, 1114 Kirby Drive, Duluth, Minnesota, 55812, USA
| | - Adam T Clark
- Institute for Biology, Karl-Franzens University of Graz, Holteigasse 6, Graz, 8010, Austria
| | - Aaron S David
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota, 55108, USA
| | - Jacob M Jungers
- Department of Agronomy and Plant Genetics, University of Minnesota, 1991 Upper Buford Circle, St. Paul, Minnesota, 55108, USA
| | - Amy E Kendig
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota, 55108, USA
| | - Charlotte E Riggs
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota, 55108, USA
| | - Jared Trost
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota, 55108, USA
- Departments of Forestry Resources, University of Minnesota, St. Paul, Minnesota, 55108, USA
| | - Xiaojing Wei
- Department of Ecology, Evolution, and Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota, 55108, USA
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98
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Zilio M, Pigoli A, Rizzi B, Geromel G, Meers E, Schoumans O, Giordano A, Adani F. Measuring ammonia and odours emissions during full field digestate use in agriculture. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 782:146882. [PMID: 33848865 DOI: 10.1016/j.scitotenv.2021.146882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/24/2021] [Accepted: 03/28/2021] [Indexed: 05/10/2023]
Abstract
The use of digestate in agriculture represents an opportunity for reducing the use of synthetic fertilizers while promoting nutrient and organic matter recycling, i.e. contributing to a circular economy. However, some environmental impacts could result from digestate use, with particular reference to N emissions, which can contribute to particulate matter formation in the atmosphere. So, correct digestate spreading methods need to be tested to reduce ammonia emission and, possibly, also to avoid annoyance to the inhabitants. In this work a digestate from organic wastes was used as a fertilizer by its injection at 15 cm, in comparison with a synthetic one (urea) for three consecutive years in open fields, measuring ammonia and odours emission. On average, the ammonia emission from digestate was of 25.6 ± 9.4 kg N Ha-1 (11.6% ± 4 of Total Ammonia Nitrogen - TAN - dosed), while urea emitted 24.8 ± 8.3 kg N Ha-1 (13.4% ± 4.5 of TAN dosed). The injected digestate also emitted less odour than urea (601 ± 531 and 1767 ± 2221 OU m-2 h-1, respectively), being ammonia coming from urea hydrolysis responsible for odour productions. The different N fertilizers did not lead to differences in crop yields, i.e. 18.5 ± 2.9 Mg grain Ha-1 and 17.4 ± 1.2 Mg grain Ha-1 for digestate and urea respectively.
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Affiliation(s)
- Massimo Zilio
- Gruppo Ricicla labs., DiSAA, Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy
| | - Ambrogio Pigoli
- Gruppo Ricicla labs., DiSAA, Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy
| | - Bruno Rizzi
- Gruppo Ricicla labs., DiSAA, Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy
| | - Gabriele Geromel
- Acqua & Sole Srl, Via Giulio Natta, 27010 Vellezzo Bellini (PV), Italy
| | - Erik Meers
- Dept. Green Chemistry & Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Oscar Schoumans
- Wageningen Environmental Research, Wageningen University and Research, PO Box 47, 6700AA Wageningen, the Netherlands
| | - Andrea Giordano
- Acqua & Sole Srl, Via Giulio Natta, 27010 Vellezzo Bellini (PV), Italy
| | - Fabrizio Adani
- Gruppo Ricicla labs., DiSAA, Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy.
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99
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Eskelinen A, Elwood E, Harrison S, Beyen E, Gremer JR. Vulnerability of grassland seed banks to resource-enhancing global changes. Ecology 2021; 102:e03512. [PMID: 34358331 DOI: 10.1002/ecy.3512] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/20/2021] [Accepted: 05/27/2021] [Indexed: 12/18/2022]
Abstract
Soil seed banks represent reservoirs of diversity in the soil that may increase resilience of communities to global changes. Two global change factors that can dramatically alter the composition and diversity of aboveground communities are nutrient enrichment and increased rainfall. In a full-factorial nutrient and rainfall addition experiment in an annual Californian grassland, we asked whether shifts in aboveground composition and diversity were reflected in belowground seed banks. Nutrient and rainfall additions increased exotic and decreased native abundances, while rainfall addition increased exotic richness, both in aboveground communities and seed banks. Under nutrient addition, forbs and short-statured plants were replaced by grasses and tall-statured species, both above and below ground, and whole-community responses to the treatments were similar. Structural equation models indicated that especially nutrient addition effects on seed banks were largely indirect via aboveground communities. However, rainfall addition also had a direct negative effect on native species richness and abundance of species with high specific leaf area (SLA) in seed banks, showing that seed banks are sensitive to the direct effects of temporary increases in rainfall. Our findings highlight the vulnerability of seed banks in annual, resource-poor grasslands to shifts in compositional and trait changes in aboveground communities and show how invasion of exotics and depletion of natives are critical for these above-belowground compositional shifts. Our findings suggest that seed banks have limited potential to buffer resource-poor annual grasslands from the community changes caused by resource enrichment.
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Affiliation(s)
- Anu Eskelinen
- Department of Physiological Diversity, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig, 04318, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstraße 4, Leipzig, 04103, Germany.,Department of Ecology and Genetics, University of Oulu, P.O. Box 8000, Oulu, FI-90014, Finland
| | - Elise Elwood
- Department of Evolution and Ecology, University of California, Davis, California, 95616, USA
| | - Susan Harrison
- Department of Environmental Science and Policy, University of California, Davis, California, 95616, USA
| | - Eva Beyen
- Department of Evolution and Ecology, University of California, Davis, California, 95616, USA
| | - Jennifer R Gremer
- Department of Evolution and Ecology, University of California, Davis, California, 95616, USA
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100
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The Potential of Mapping Grassland Plant Diversity with the Links among Spectral Diversity, Functional Trait Diversity, and Species Diversity. REMOTE SENSING 2021. [DOI: 10.3390/rs13153034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mapping biodiversity is essential for assessing conservation and ecosystem services in global terrestrial ecosystems. Compared with remotely sensed mapping of forest biodiversity, that of grassland plant diversity has been less studied, because of the small size of individual grass species and the inherent difficulty in identifying these species. The technological advances in unmanned aerial vehicle (UAV)-based or proximal imaging spectroscopy with high spatial resolution provide new approaches for mapping and assessing grassland plant diversity based on spectral diversity and functional trait diversity. However, relatively few studies have explored the relationships among spectral diversity, remote-sensing-estimated functional trait diversity, and species diversity in grassland ecosystems. In this study, we examined the links among spectral diversity, functional trait diversity, and species diversity in a semi-arid grassland monoculture experimental site. The results showed that (1) different grassland plant species harbored different functional traits or trait combinations (functional trait diversity), leading to different spectral patterns (spectral diversity). (2) The spectral diversity of grassland plant species increased gradually from the visible (VIR, 400–700 nm) to the near-infrared (NIR, 700–1100 nm) region, and to the short-wave infrared (SWIR, 1100–2400 nm) region. (3) As the species richness increased, the functional traits and spectral diversity increased in a nonlinear manner, finally tending to saturate. (4) Grassland plant species diversity could be accurately predicted using hyperspectral data (R2 = 0.73, p < 0.001) and remotely sensed functional traits (R2 = 0.66, p < 0.001) using cluster algorithms. This will enhance our understanding of the effect of biodiversity on ecosystem functions and support regional grassland biodiversity conservation.
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