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Qu LP, Dong G, Chen J, Xiao J, De Boeck HJ, Chen J, Jiang S, Batkhishig O, Legesse TG, Xin X, Shao C. Soil environmental anomalies dominate the responses of net ecosystem productivity to heatwaves in three Mongolian grasslands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 944:173742. [PMID: 38839012 DOI: 10.1016/j.scitotenv.2024.173742] [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: 01/17/2024] [Revised: 05/28/2024] [Accepted: 06/01/2024] [Indexed: 06/07/2024]
Abstract
Climate change is causing more frequent and intense heatwaves. Therefore, it is important to understand how heatwaves affect the terrestrial carbon cycle, especially in grasslands, which are especially susceptible to climate extremes. This study assessed the impact of naturally occurring, simultaneous short-term heatwaves on CO2 fluxes in three ecosystems on the Mongolia Plateau: meadow steppe (MDW), typical steppe (TPL), and shrub-grassland (SHB). During three heatwaves, net ecosystem productivity (NEP) was reduced by 86 %, 178 %, and 172 % at MDW, TPL, and SHB, respectively. The changes in ecosystem respiration, gross primary production, evapotranspiration, and water use efficiency were divergent, indicating the mechanisms underlying the observed NEP decreases among the sites. The impact of the heatwave in MDW was mitigated by the high soil water content, which enhanced evapotranspiration and subsequent cooling effects. However, at TPL, insufficient soil water led to combined thermal and drought stress and low resilience. At SHB, the ecosystem's low tolerance to an August heatwave was heavily influenced by species phenology, as it coincided with the key phenological growing phase of plants. The potential key mechanism of divergent NEP response to heatwaves lies in the divergent stability and varying importance of environmental factors, combined with the specific sensitivity of NEP to each factor in ecosystems. Furthermore, our findings suggest that anomalies in soil environment, rather than atmospheric anomalies, are the primary determinants of NEP anomalies during heatwaves. This challenges the conventional understanding of heatwaves as a discrete and ephemeral periods of high air temperatures. Instead, heatwaves should be viewed as chronologically variable, compound, and time-sensitive environmental stressors. The ultimate impact of heatwaves on ecosystems is co-determined by a complex interplay of environmental, biological, and heatwave features.
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Affiliation(s)
- Lu-Ping Qu
- College of JunCao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Gang Dong
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China; School of Life Science, Shanxi University, Taiyuan, China
| | - Jiquan Chen
- Department of Geography, Environment, and Spatial Sciences, Michigan State University, East Lansing, MI 48823, USA
| | - Jingfeng Xiao
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA
| | - Hans J De Boeck
- Research Group of Plants and Ecosystems (PLECO), Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium; School of Ecology and Environmental Sciences, Yunnan University, Kunming 650091, China
| | - Jingyan Chen
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Shicheng Jiang
- Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China
| | - Ochirbat Batkhishig
- Institute of Geography, Mongolian Academy of Sciences, Ulaanbaartar 210620, Mongolia
| | - Tsegaye Gemechu Legesse
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaoping Xin
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Changliang Shao
- State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China, National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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2
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Huang Y, Chen XS, Zhu L. Differential responses of ecosystem stability to climatic and anthropogenic factors in connected and isolated lake basins on the Yangtze River. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 359:121014. [PMID: 38704954 DOI: 10.1016/j.jenvman.2024.121014] [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: 02/29/2024] [Revised: 04/06/2024] [Accepted: 04/23/2024] [Indexed: 05/07/2024]
Abstract
Maintaining optimal ecological security in the Yangtze River-connected and isolated lake basins is of great significance to national projects involving Yangtze River protection. Ecosystem stability and associated factors are important components of ecological security in these basins. However, few studies have focused on ecosystem stability and its driving factors over long periods in the Yangtze River Basin. In this study, a remote sensing index was used to analyze the spatiotemporal variation in the ecosystem stability of the Dongting Lake Basin (DTL), Poyang Lake Basin (PYL), and the isolated Chaohu Lake Basin (CHL) and Taihu Lake Basin (THL) in the Yangtze River over the period 2000-2022 to determine the potential affecting factors. The results showed fluctuations in the ecosystem stability of the DTL and PYL, while a V-shape was observed for the CHL and THL during the same period; the closer to the lake, the weaker the stability of the ecosystem, especially in the DTL and PYL. Moreover, the ecosystem stability was greater in the DTL and PYL than in the CHL and THL. The spillover effect of anthropogenic activities on the ecosystem stability of the four basins and the direct effect of temperature have the greatest effect on the ecosystem stability. Specifically, the ecosystem stability index for the area around the DTL and PYL decreased with increasing human interference, whereas the opposite was observed in the CHL and THL. The effect of temperature was negative for the ecosystem stability of DTL and PYL and significantly positive for CHL and THL, at a level of 0.01 %. The findings of this study provide significant information for targeted ecological restoration of the Yangtze River Basin.
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Affiliation(s)
- Ying Huang
- College of Economics and Management, Hunan Institute of Science and Technology, Yueyang 414000, China
| | - Xin-Sheng Chen
- School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China.
| | - Lianlian Zhu
- School of Earth Sciences and Spatial Information Engineering, Institute of Subtropical Agriculture, Hunan University of Science and Technology, Xiangtan 411201, China
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Keen RM, Bachle S, Bartmess M, Nippert JB. Combined effects of fire and drought are not sufficient to slow shrub encroachment in tallgrass prairie. Oecologia 2024; 204:727-742. [PMID: 38492034 DOI: 10.1007/s00442-024-05526-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 02/03/2024] [Indexed: 03/18/2024]
Abstract
Woody encroachment-the spread of woody vegetation in open ecosystems-is a common threat to grasslands worldwide. Reversing encroachment can be exceedingly difficult once shrubs become established, particularly clonal species that resprout following disturbance. Single stressors are unlikely to reverse woody encroachment, but using multiple stressors in tandem could be successful in slowing or reversing encroachment. We explored whether increasing fire frequency in conjunction with multi-year drought could reduce growth and survival of encroaching shrubs in a tallgrass prairie in northeastern Kansas, USA. Passive rainout shelters (~ 50% rainfall reduction) were constructed over mature clonal shrubs (Cornus drummondii) and co-existing C4 grasses in two fire treatments (1-year and 4-year burn frequency). Leaf- and whole-plant level physiological responses to drought and fire frequency were monitored in shrubs and grasses from 2019 to 2022. Shrub biomass and stem density following fire were unaffected by five years of consecutive drought treatment, regardless of fire frequency. The drought treatment had more negative effects on grass leaf water potential and photosynthetic rates compared to shrubs. Shrub photosynthetic rates were remarkably stable across each growing season. Overall, we found that five consecutive years of moderate drought in combination with fire was not sufficient to reduce biomass production or stem density in an encroaching clonal shrub (C. drummondii). These results suggest that moderate but chronic press-drought events do not sufficiently stress encroaching clonal shrubs to negatively impact their resilience following fire events, even when fire frequency is high.
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Affiliation(s)
- R M Keen
- Division of Biology, Kansas State University, Manhattan, KS, USA.
| | - S Bachle
- Division of Biology, Kansas State University, Manhattan, KS, USA
- LI-COR Biosciences, Lincoln, NE, 68504, USA
| | - M Bartmess
- United States Department of Agriculture, Natural Resource Conservation Service, Pottawatomie County, KS, USA
| | - J B Nippert
- Division of Biology, Kansas State University, Manhattan, KS, USA
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Li X, Song Z, Hu Y, Qiao J, Chen Y, Wang S, Yue P, Chen M, Ke Y, Xu C, Yu Q, Zuo X. Drought intensity and post-drought precipitation determine vegetation recovery in a desert steppe in Inner Mongolia, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167449. [PMID: 37832659 DOI: 10.1016/j.scitotenv.2023.167449] [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: 05/30/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023]
Abstract
Extreme drought events are expected to increase in frequency and severity, posing significant threats to ecosystems worldwide. While considerable research has been concentrated on the effects of climate extremes on the stability of grasslands, the process by which grassland productivity may recover after extreme drought events are still not well understood. Here, we conducted a four-year (2019-2022) recovery investigation after four-year's (2015-2018) extreme drought treatments of different intensities (control, press and pulse) to explore the vegetation recovery of desert-grassland ecosystems Inner Mongolia, China. Press drought involved a 66 % reduction in natural precipitation from May to August, while pulse drought reduced it by 100 % during June and July. We found that both press and pulse droughts led to a sharp decrease in aboveground net primary productivity (ANPP) after four years, primarily due to reduced growth, density, and productivity of annual and perennial plants. However, ANPP under pulse drought could recover fully after four years of stopping of drought treatment, and it could not under press drought. Additionally, community structure (i.e., species richness, plant density, and height) fully recovered within 1 year after the end of the two extreme drought treatments. Both plant density and height contributed to the ANPP recovery after press and pulse droughts. Structural equation modeling (SEM) results further revealed that the reduction in ANPP during the extreme drought was primarily due to a decrease in plant density caused by reduced soil water content. The recovery of ANPP in pulse drought was directly caused by increased soil water content in the post-extreme drought. These results suggest that drought intensity and precipitation determine ANPP recovery in a degraded desert steppe. Our findings are crucial for deepening understanding of the processes and mechanisms of ecosystem recovery after extreme drought, as well as for the successful management and protection of grassland ecosystems.
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Affiliation(s)
- Xiangyun Li
- Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region, Gansu Province, Lanzhou 730000, China
| | - Zhaobin Song
- Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region, Gansu Province, Lanzhou 730000, China
| | - Ya Hu
- Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region, Gansu Province, Lanzhou 730000, China
| | - Jingjuan Qiao
- Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region, Gansu Province, Lanzhou 730000, China
| | - Yuheng Chen
- Ecology and Biodiversity Group, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Shaokun Wang
- Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Naiman Desertification Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region, Gansu Province, Lanzhou 730000, China
| | - Ping Yue
- Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Naiman Desertification Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region, Gansu Province, Lanzhou 730000, China
| | - Min Chen
- Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Naiman Desertification Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region, Gansu Province, Lanzhou 730000, China
| | - Yuguang Ke
- Hulunber Grassland Ecosystem National Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 100081 Beijing, China
| | - Chong Xu
- Hulunber Grassland Ecosystem National Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 100081 Beijing, China
| | - Qiang Yu
- School of Grassland Science, Beijing Forestry University, Beijing 10008, China
| | - Xiaoan Zuo
- Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Naiman Desertification Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Science, Lanzhou 730000, China; Key Laboratory of Stress Physiology and Ecology in Cold and Arid Region, Gansu Province, Lanzhou 730000, China.
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Morais J, Tebbett SB, Morais RA, Bellwood DR. Natural recovery of corals after severe disturbance. Ecol Lett 2024; 27:e14332. [PMID: 37850584 DOI: 10.1111/ele.14332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/28/2023] [Accepted: 10/06/2023] [Indexed: 10/19/2023]
Abstract
Ecosystem recovery from human-induced disturbances, whether through natural processes or restoration, is occurring worldwide. Yet, recovery dynamics, and their implications for broader ecosystem management, remain unclear. We explored recovery dynamics using coral reefs as a case study. We tracked the fate of 809 individual coral recruits that settled after a severe bleaching event at Lizard Island, Great Barrier Reef. Recruited Acropora corals, first detected in 2020, grew to coral cover levels that were equivalent to global average coral cover within just 2 years. Furthermore, we found that just 11.5 Acropora recruits per square meter were sufficient to reach this cover within 2 years. However, wave exposure, growth form and colony density had a marked effect on recovery rates. Our results underscore the importance of considering natural recovery in management and restoration and highlight how lessons learnt from reef recovery can inform our understanding of recovery dynamics in high-diversity climate-disturbed ecosystems.
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Affiliation(s)
- Juliano Morais
- Research Hub for Coral Reef Ecosystem Functions and College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Sterling B Tebbett
- Research Hub for Coral Reef Ecosystem Functions and College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Renato A Morais
- Research Hub for Coral Reef Ecosystem Functions and College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Paris Sciences et Lettres Université, École Pratique des Hautes Études, EPHE-UPVD-CNRS, UAR 3278 CRIOBE, University of Perpignan, Perpignan, France
| | - David R Bellwood
- Research Hub for Coral Reef Ecosystem Functions and College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
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6
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Chen W, Jiang L, Jia R, Tang B, Jiang H, Wang Y, Lu X, Su J, Bai Y. Plant litter loss exacerbates drought influences on grasslands. THE NEW PHYTOLOGIST 2024; 241:142-153. [PMID: 37932883 DOI: 10.1111/nph.19374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 09/25/2023] [Indexed: 11/08/2023]
Abstract
Plant litter is known to affect soil, community, and ecosystem properties. However, we know little about the capacity of litter to modulate grassland responses to climate change. Using a 7-yr litter removal experiment in a semiarid grassland, here we examined how litter removal interacts with a 2-yr drought to affect soil environments, plant community composition, and ecosystem function. Litter loss exacerbates the negative impacts of drought on grasslands. Litter removal increased soil temperature but reduced soil moisture and nitrogen mineralization, which substantially increased the negative impacts of drought on primary productivity and the abundance of perennial rhizomatous graminoids. Moreover, complete litter removal shifted plant community composition from grass-dominated to forb-dominated and reduced species and functional group asynchrony, resulting in lower ecosystem temporal stability. Our results suggest that ecological processes that lead to reduction in litter, such as burning, grazing, and haying, may render ecosystems more vulnerable and impair the capacity of grasslands to withstand drought events.
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Affiliation(s)
- Wanjie Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Lin Jiang
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Ruoyu Jia
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
| | - Bo Tang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Hongzhi Jiang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yang Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Xiaoming Lu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jishuai Su
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yongfei Bai
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, China
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7
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Schärer ML, Lüscher A, Kahmen A. Post-drought compensatory growth in perennial grasslands is determined by legacy effects of the soil and not by plants. THE NEW PHYTOLOGIST 2023; 240:2265-2275. [PMID: 37789694 DOI: 10.1111/nph.19291] [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: 06/27/2023] [Accepted: 09/07/2023] [Indexed: 10/05/2023]
Abstract
Grasslands recovering from drought have repeatedly been shown to outperform non-drought-stressed grasslands in biomass production. The mechanisms that lead to the unexpectedly high biomass production in grasslands recovering from drought are, however, not understood. To disentangle plant-intrinsic and plant-extrinsic (soil) drought legacy effects on grassland recovery from drought, we designed a factorial field experiment where Lolium perenne plants that were exposed to either a 2-month drought or to well-watered control conditions were transplanted into control and drought-stressed soil and rewetted thereafter. Drought and rewetting (DRW) resulted in negative drought legacy effects of formerly drought-stressed plants (DRWp ) compared with control plants (Ctrp ) when decoupled from soil-mediated DRW effects, with DRWp showing less aboveground productivity (-13%), restricted N nutrition, and higher δ13 C compared with Ctrp . However, plants grown on formerly drought-stressed soil (DRWs ) showed enhanced aboveground productivity (+82%), improved N nutrition, and higher δ13 C values relative to plants grown on control soil (Ctrs ), irrespective of the plants' pretreatment. Our study shows that the higher post-drought productivity of perennial grasslands recovering from drought relative to non-drought-stressed controls is induced by soil-mediated DRW legacy effects which improve plant N nutrition and photosynthetic capacity and that these effects countervail negative plant-intrinsic drought legacy effects.
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Affiliation(s)
- Marie-Louise Schärer
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, CH-4057, Basel, Switzerland
- Forage Production and Grassland Systems, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland
| | - Andreas Lüscher
- Forage Production and Grassland Systems, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, CH-4057, Basel, Switzerland
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8
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Wilcox KR, Chen A, Avolio ML, Butler EE, Collins S, Fisher R, Keenan T, Kiang NY, Knapp AK, Koerner SE, Kueppers L, Liang G, Lieungh E, Loik M, Luo Y, Poulter B, Reich P, Renwick K, Smith MD, Walker A, Weng E, Komatsu KJ. Accounting for herbaceous communities in process-based models will advance our understanding of "grassy" ecosystems. GLOBAL CHANGE BIOLOGY 2023; 29:6453-6477. [PMID: 37814910 DOI: 10.1111/gcb.16950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/01/2023] [Indexed: 10/11/2023]
Abstract
Grassland and other herbaceous communities cover significant portions of Earth's terrestrial surface and provide many critical services, such as carbon sequestration, wildlife habitat, and food production. Forecasts of global change impacts on these services will require predictive tools, such as process-based dynamic vegetation models. Yet, model representation of herbaceous communities and ecosystems lags substantially behind that of tree communities and forests. The limited representation of herbaceous communities within models arises from two important knowledge gaps: first, our empirical understanding of the principles governing herbaceous vegetation dynamics is either incomplete or does not provide mechanistic information necessary to drive herbaceous community processes with models; second, current model structure and parameterization of grass and other herbaceous plant functional types limits the ability of models to predict outcomes of competition and growth for herbaceous vegetation. In this review, we provide direction for addressing these gaps by: (1) presenting a brief history of how vegetation dynamics have been developed and incorporated into earth system models, (2) reporting on a model simulation activity to evaluate current model capability to represent herbaceous vegetation dynamics and ecosystem function, and (3) detailing several ecological properties and phenomena that should be a focus for both empiricists and modelers to improve representation of herbaceous vegetation in models. Together, empiricists and modelers can improve representation of herbaceous ecosystem processes within models. In so doing, we will greatly enhance our ability to forecast future states of the earth system, which is of high importance given the rapid rate of environmental change on our planet.
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Affiliation(s)
- Kevin R Wilcox
- University of North Carolina Greensboro, Greensboro, North Carolina, USA
- University of Wyoming, Laramie, Wyoming, USA
| | - Anping Chen
- Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
| | - Meghan L Avolio
- Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ethan E Butler
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
| | - Scott Collins
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Rosie Fisher
- CICERO Centre for International Cimate Research, Forskningsparken, Oslo, Norway
| | - Trevor Keenan
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Nancy Y Kiang
- NASA Goddard Institute for Space Studies, New York, New York, USA
| | - Alan K Knapp
- Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
| | - Sally E Koerner
- University of North Carolina Greensboro, Greensboro, North Carolina, USA
| | - Lara Kueppers
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Guopeng Liang
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
| | - Eva Lieungh
- Natural History Museum, University of Oslo, Oslo, Norway
| | - Michael Loik
- Department of Environmental Studies, University of California, Santa Cruz, California, USA
| | - Yiqi Luo
- School of Integrative Plant Science, Cornell University, Ithaca, New York, USA
| | - Ben Poulter
- Biospheric Sciences Lab, NASA GSFC, Greenbelt, Maryland, USA
| | - Peter Reich
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | | | - Melinda D Smith
- Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
| | - Anthony Walker
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Ensheng Weng
- NASA Goddard Institute for Space Studies, New York, New York, USA
- Center for Climate Systems Research, Columbia University, New York, New York, USA
| | - Kimberly J Komatsu
- University of North Carolina Greensboro, Greensboro, North Carolina, USA
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Han W, Guan J, Zheng J, Liu Y, Ju X, Liu L, Li J, Mao X, Li C. Probabilistic assessment of drought stress vulnerability in grasslands of Xinjiang, China. FRONTIERS IN PLANT SCIENCE 2023; 14:1143863. [PMID: 37008478 PMCID: PMC10062607 DOI: 10.3389/fpls.2023.1143863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/01/2023] [Indexed: 06/19/2023]
Abstract
In the process of climate warming, drought has increased the vulnerability of ecosystems. Due to the extreme sensitivity of grasslands to drought, grassland drought stress vulnerability assessment has become a current issue to be addressed. First, correlation analysis was used to determine the characteristics of the normalized precipitation evapotranspiration index (SPEI) response of the grassland normalized difference vegetation index (NDVI) to multiscale drought stress (SPEI-1 ~ SPEI-24) in the study area. Then, the response of grassland vegetation to drought stress at different growth periods was modeled using conjugate function analysis. Conditional probabilities were used to explore the probability of NDVI decline to the lower percentile in grasslands under different levels of drought stress (moderate, severe and extreme drought) and to further analyze the differences in drought vulnerability across climate zones and grassland types. Finally, the main influencing factors of drought stress in grassland at different periods were identified. The results of the study showed that the spatial pattern of drought response time of grassland in Xinjiang had obvious seasonality, with an increasing trend from January to March and November to December in the nongrowing season and a decreasing trend from June to October in the growing season. August was the most vulnerable period for grassland drought stress, with the highest probability of grassland loss. When the grasslands experience a certain degree of loss, they develop strategies to mitigate the effects of drought stress, thereby decreasing the probability of falling into the lower percentile. Among them, the highest probability of drought vulnerability was found in semiarid grasslands, as well as in plains grasslands and alpine subalpine grasslands. In addition, the primary drivers of April and August were temperature, whereas for September, the most significant influencing factor was evapotranspiration. The results of the study will not only deepen our understanding of the dynamics of drought stress in grasslands under climate change but also provide a scientific basis for the management of grassland ecosystems in response to drought and the allocation of water in the future.
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Affiliation(s)
- Wanqiang Han
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
| | - Jingyun Guan
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Tourism, Xinjiang University of Finance & Economics, Urumqi, China
| | - Jianghua Zheng
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
| | - Yujia Liu
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
| | - Xifeng Ju
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
| | - Liang Liu
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
| | - Jianhao Li
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
| | - Xurui Mao
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
| | - Congren Li
- College of Geography and Remote Sensing Science, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
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10
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Holdo RM, Nippert JB. Linking resource- and disturbance-based models to explain tree-grass coexistence in savannas. THE NEW PHYTOLOGIST 2023; 237:1966-1979. [PMID: 36451534 DOI: 10.1111/nph.18648] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 11/06/2022] [Indexed: 06/17/2023]
Abstract
Savannas cover a significant fraction of the Earth's land surface. In these ecosystems, C3 trees and C4 grasses coexist persistently, but the mechanisms explaining coexistence remain subject to debate. Different quantitative models have been proposed to explain coexistence, but these models make widely contrasting assumptions about which mechanisms are responsible for savanna persistence. Here, we show that no single existing model fully captures all key elements required to explain tree-grass coexistence across savanna rainfall gradients, but many models make important contributions. We show that recent empirical work allows us to combine many existing elements with new ideas to arrive at a synthesis that combines elements of two dominant frameworks: Walter's two-layer model and demographic bottlenecks. We propose that functional rooting separation is necessary for coexistence and is the crux of the coexistence problem. It is both well-supported empirically and necessary for tree persistence, given the comprehensive grass superiority for soil moisture acquisition. We argue that eventual tree dominance through shading is precluded by ecohydrological constraints in dry savannas and by fire and herbivores in wet savannas. Strong asymmetric grass-tree competition for soil moisture limits tree growth, exposing trees to persistent demographic bottlenecks.
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Affiliation(s)
- Ricardo M Holdo
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - Jesse B Nippert
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
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11
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Luo W, Muraina TO, Griffin-Nolan RJ, Ma W, Song L, Fu W, Yu Q, Knapp AK, Wang Z, Han X, Collins SL. Responses of a semiarid grassland to recurrent drought are linked to community functional composition. Ecology 2023; 104:e3920. [PMID: 36416074 DOI: 10.1002/ecy.3920] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 10/05/2022] [Indexed: 11/24/2022]
Abstract
Recurrent droughts are an inevitable consequence of climate change, yet how grasslands respond to such events is unclear. We conducted a 6-year rainfall manipulation experiment in a semiarid grassland that consisted of an initial 2-year drought (2015-2016), followed by a recovery period (2017-2018) and, finally, a second 2-year drought (2019-2020). In each year, we estimated aboveground net primary productivity (ANPP), species richness, community-weighted mean (CWM) plant traits, and several indices of functional diversity. The initial drought led to reduced ANPP, which was primarily driven by limited growth of forbs in the first year and grasses in the second year. Total ANPP completely recovered as the rapid recovery of grass productivity compensated for the slow recovery of forb productivity. The subsequent drought led to a greater reduction in total ANPP than the initial drought due to the greater decline of both grass and forb productivity. The structural equation models revealed that soil moisture influenced ANPP responses directly during the initial drought, and indirectly during the subsequent drought by lowering functional diversity, which resulted in reduced total ANPP. Additionally, ANPP was positively influenced by CWM plant height and leaf nitrogen during the recovery period and recurrent drought, respectively. Overall, the greater impact of the second drought on ecosystem function than the initial drought, as well as the underlying differential mechanism, underscores the need for an understanding of how increased drought frequency may alter semiarid grassland functioning.
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Affiliation(s)
- Wentao Luo
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Taofeek O Muraina
- Department of Animal Health and Production, Oyo State College of Agriculture and Technology, Igbo-Ora, Nigeria
| | | | - Wang Ma
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Lin Song
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Wei Fu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Qiang Yu
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Alan K Knapp
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA.,Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
| | - Zhengwen Wang
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Xingguo Han
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.,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
| | - Scott L Collins
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
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12
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Ingrisch J, Umlauf N, Bahn M. Functional thresholds alter the relationship of plant resistance and recovery to drought. Ecology 2023; 104:e3907. [PMID: 36314950 PMCID: PMC10078541 DOI: 10.1002/ecy.3907] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 07/13/2022] [Accepted: 08/29/2022] [Indexed: 02/03/2023]
Abstract
The ecological consequences of future droughts are difficult to predict due to a limited understanding of the nonlinear responses of plants to increasing drought intensity, which can change abruptly when critical thresholds of drought intensity are crossed. Drought responses are composed of resistance and postdrought recovery. Although it is well established that higher drought intensity increases the impact and, thus, reduces plant resistance, less is known about how drought intensity affects recovery and how resistance and recovery are related. In this study, we tested the hypothesis that resistance, recovery, and their relationship change abruptly upon crossing critical thresholds of drought intensity. We exposed mesocosms of two monospecific stands of the common grassland species Dactylis glomerata and Plantago lanceolata to a large gradient of drought intensity and quantified the resistance and recovery of multiple measures of plant productivity, including gross-primary productivity, vegetative height, Normalized Difference Vegetation Index, and aboveground biomass production. Drought intensity had nonlinear and contrasting effects on plant productivity during drought and recovery, which differed between the two species. Increasing drought intensity decreased the resistance of plant productivity and caused rapid compensatory growth during postdrought recovery, the degree of which was highly dependent on drought intensity. Across multiple response parameters two thresholds of drought intensity emerged, upon which we observed abrupt changes in plant resistance and recovery, as well as their relationship. We conclude that across gradients of drought intensity resistance and recovery are tightly coupled and that both the magnitude and the direction of drought effects on resistance and recovery can change abruptly upon specific thresholds of stress intensity. These findings highlight the urgent need to account for nonlinear responses of resistance and recovery to drought intensity as critical drivers of productivity in a changing climate.
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Affiliation(s)
| | - Nikolaus Umlauf
- Department of StatisticsUniversity of InnsbruckInnsbruckAustria
| | - Michael Bahn
- Department of EcologyUniversity of InnsbruckInnsbruckAustria
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13
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Irob K, Blaum N, Weiss‐Aparicio A, Hauptfleisch M, Hering R, Uiseb K, Tietjen B. Savanna resilience to droughts increases with the proportion of browsing wild herbivores and plant functional diversity. J Appl Ecol 2023. [DOI: 10.1111/1365-2664.14351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Katja Irob
- Freie Universität Berlin, Theoretical Ecology Institute of Biology Berlin Germany
| | - Niels Blaum
- Plant Ecology and Nature Conservation University of Potsdam Potsdam Germany
| | - Alex Weiss‐Aparicio
- Freie Universität Berlin, Theoretical Ecology Institute of Biology Berlin Germany
| | - Morgan Hauptfleisch
- Biodiversity Research Centre Namibia University of Science and Technology Windhoek Namibia
| | - Robert Hering
- Plant Ecology and Nature Conservation University of Potsdam Potsdam Germany
| | - Kenneth Uiseb
- Ministry of Environment, Forestry and Tourism Windhoek Namibia
| | - Britta Tietjen
- Freie Universität Berlin, Theoretical Ecology Institute of Biology Berlin Germany
- Berlin‐Brandenburg Institute of Advanced Biodiversity Research (BBIB) Berlin Germany
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14
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Zhou H, Hou L, Lv X, Yang G, Wang Y, Wang X. Compensatory growth as a response to post-drought in grassland. FRONTIERS IN PLANT SCIENCE 2022; 13:1004553. [PMID: 36531403 PMCID: PMC9752846 DOI: 10.3389/fpls.2022.1004553] [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: 07/27/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
Grasslands are structurally and functionally controlled by water availability. Ongoing global change is threatening the sustainability of grassland ecosystems through chronic alterations in climate patterns and resource availability, as well as by the increasing frequency and intensity of anthropogenic perturbations. Compared with many studies on how grassland ecosystems respond during drought, there are far fewer studies focused on grassland dynamics after drought. Compensatory growth, as the ability of plants to offset the adverse effects of environmental or anthropogenic perturbations, is a common phenomenon in grassland. However, compensatory growth induced by drought and its underlying mechanism across grasslands remains not clear. In this review, we provide examples of analogous compensatory growth from different grassland types across drought characteristics (intensity, timing, and duration) and explain the effect of resource availability on compensatory growth and their underlying mechanisms. Based on our review of the literature, a hypothetic framework for integrating plant, root, and microbial responses is also proposed to increase our understanding of compensatory growth after drought. This research will advance our understanding of the mechanisms of grassland ecosystem functioning in response to climate change.
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Affiliation(s)
- Huailin Zhou
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing, China
| | - Lulu Hou
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaomin Lv
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing, China
| | - Guang Yang
- College of Teacher Education, Capital Normal University, Beijing, China
| | - Yuhui Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xu Wang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
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15
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Wilschut RA, De Long JR, Geisen S, Hannula SE, Quist CW, Snoek B, Steinauer K, Wubs ERJ, Yang Q, Thakur MP. Combined effects of warming and drought on plant biomass depend on plant woodiness and community type: a meta-analysis. Proc Biol Sci 2022; 289:20221178. [PMID: 36196543 PMCID: PMC9533002 DOI: 10.1098/rspb.2022.1178] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Global warming and precipitation extremes (drought or increased precipitation) strongly affect plant primary production and thereby terrestrial ecosystem functioning. Recent syntheses show that combined effects of warming and precipitation extremes on plant biomass are generally additive, while individual experiments often show interactive effects, indicating that combined effects are more negative or positive than expected based on the effects of single factors. Here, we examined whether variation in biomass responses to single and combined effects of warming and precipitation extremes can be explained by plant growth form and community type. We performed a meta-analysis of 37 studies, which experimentally crossed warming and precipitation treatments, to test whether biomass responses to combined effects of warming and precipitation extremes depended on plant woodiness and community type (monocultures versus mixtures). Our results confirmed that the effects of warming and precipitation extremes were overall additive. However, combined effects of warming and drought on above- and belowground biomass were less negative in woody- than in herbaceous plant systems and more negative in plant mixtures than in monocultures. We further show that drought effects on plant biomass were more negative in greenhouse- than in field studies, suggesting that greenhouse experiments may overstate drought effects in the field. Our results highlight the importance of plant system characteristics to better understand plant responses to climate change.
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Affiliation(s)
- Rutger A Wilschut
- Ecology, Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz 78464, Germany.,Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands
| | - Jonathan R De Long
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands.,Louis Bolk Institute, Kosterijland 3-5, Bunnik 3981 AJ, The Netherlands
| | - Stefan Geisen
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands.,Laboratory of Nematology, Wageningen University, Wageningen 6708 PB, The Netherlands
| | - S Emilia Hannula
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands.,Institute of Environmental Sciences, Leiden University, Einsteinweg 2, Leiden 2333CC, The Netherlands
| | - Casper W Quist
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands.,Biosystematics Group, Wageningen University, Wageningen 6708 PB, The Netherlands
| | - Basten Snoek
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands.,Theoretical Biology and Bioinformatics, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands
| | - Katja Steinauer
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands
| | - E R Jasper Wubs
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands.,Sustainable Agroecosystems Group, Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 2, Zürich 8092, Switzerland
| | - Qiang Yang
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands.,State Key Laboratory of Grassland Agro-Ecosystems, College of Ecology, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China
| | - Madhav P Thakur
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen 6708 PB, The Netherlands.,Institute of Ecology and Evolution and Oeschger Centre for Climate Change Research, University of Bern, Bern 3012, Switzerland
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16
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Reintroducing bison results in long-running and resilient increases in grassland diversity. Proc Natl Acad Sci U S A 2022; 119:e2210433119. [PMID: 36037376 PMCID: PMC9457053 DOI: 10.1073/pnas.2210433119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The widespread extirpation of megafauna may have destabilized ecosystems and altered biodiversity globally. Most megafauna extinctions occurred before the modern record, leaving it unclear how their loss impacts current biodiversity. We report the long-term effects of reintroducing plains bison (Bison bison) in a tallgrass prairie versus two land uses that commonly occur in many North American grasslands: 1) no grazing and 2) intensive growing-season grazing by domesticated cattle (Bos taurus). Compared to ungrazed areas, reintroducing bison increased native plant species richness by 103% at local scales (10 m2) and 86% at the catchment scale. Gains in richness continued for 29 y and were resilient to the most extreme drought in four decades. These gains are now among the largest recorded increases in species richness due to grazing in grasslands globally. Grazing by domestic cattle also increased native plant species richness, but by less than half as much as bison. This study indicates that some ecosystems maintain a latent potential for increased native plant species richness following the reintroduction of native herbivores, which was unmatched by domesticated grazers. Native-grazer gains in richness were resilient to an extreme drought, a pressure likely to become more common under future global environmental change.
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17
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Climatic history, constraints, and the plasticity of phytochemical traits under water stress. Ecosphere 2022. [DOI: 10.1002/ecs2.4167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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18
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Hossain ML, Li J, Hoffmann S, Beierkuhnlein C. Biodiversity showed positive effects on resistance but mixed effects on resilience to climatic extremes in a long-term grassland experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 827:154322. [PMID: 35257775 DOI: 10.1016/j.scitotenv.2022.154322] [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: 11/26/2021] [Revised: 02/20/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
Understanding the role of biodiversity in maintaining ecosystem functioning and stability under increasing frequency and magnitude of climatic extremes has fascinated ecologists for decades. Although growing evidence suggests that biodiversity affects ecosystem productivity and buffers ecosystem against climatic extremes, it remains unclear whether the stability of an ecosystem is caused by its resistance against disturbances or resilience towards perturbations or both. In attempting to explore how species richness affects resistance and resilience of above-ground net primary productivity (ANPP) against climatic extremes, we analyzed the grassland ANPP of the long-running (1997-2020) Bayreuth Biodiversity experiment in Germany. We used the Standardized Precipitation Evapotranspiration Index to identify climatic conditions based on 5- and 7-class classifications of climatic conditions. Mixed-effects models and post-hoc test show that ANPP varied significantly among different intensities (e.g. moderate or extreme) and directions (e.g. dry or wet) of climatic conditions, with the highest ANPP in extreme wet and the lowest in extreme dry conditions. Resistance and resilience of ANPP to climatic extremes in different intensities were examined by linear-mixed effects models and we found that species richness increased ecosystem resistance against all dry and wet climatic extremes, but decreased ecosystem resilience towards all dry climatic extremes. Species richness had no effects on ecosystem resilience towards wet climatic extremes. When the five level of species richness treatment (i.e., 1, 2, 4, 8, and 16 species) were considered, the relationships between species richness and resistance and resilience of ANPP under extreme wet and dry conditions remained similar. Our study emphasizes that plant communities with greater species richness need to be maintained to stabilize ecosystem productivity and increase resistance against different climatic extremes.
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Affiliation(s)
- Md Lokman Hossain
- Department of Geography, Hong Kong Baptist University, Baptist University Road, Kowloon Tong, Hong Kong, China; Department of Biogeography, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany; Department of Environment Protection Technology, German University Bangladesh, 1702 Gazipur, Bangladesh
| | - Jianfeng Li
- Department of Geography, Hong Kong Baptist University, Baptist University Road, Kowloon Tong, Hong Kong, China.
| | - Samuel Hoffmann
- Department of Biogeography, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
| | - Carl Beierkuhnlein
- Department of Biogeography, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany; BayCEER, Bayreuth Center for Ecology and Environmental Research, Universitätsstr. 30, 95447 Bayreuth, Germany
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19
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He YL, Wang JS, Tian DS, Quan Q, Jiang L, Ma FF, Yang L, Zhang FY, Zhou QP, Niu SL. Long-term drought aggravates instability of alpine grassland productivity to extreme climatic event. Ecology 2022; 103:e3792. [PMID: 35718756 DOI: 10.1002/ecy.3792] [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: 11/02/2021] [Revised: 05/13/2022] [Accepted: 05/19/2022] [Indexed: 11/09/2022]
Abstract
The frequency and severity of extreme weather events are increasing and expected to increase more in the future together with global change. However, how extreme events and global change factors interactively influence community structures and ecosystem processes is largely unknown. Here, we investigated responses of temporal stability and resilience of aboveground net primary productivity (ANPP) of an alpine meadow to an extreme flooding event under different treatments of experimental drought and clipping. We found that ecosystems that were exposed to drought treatments for three years significantly decreased temporal stability of community productivity but increased resilience to flooding, whereas their resistance to or recovery from flooding did not change. Neither clipping nor its interaction with drought altered responses of these community stability metrics to flooding. Drought treatments significantly decreased plant species richness, asynchrony and dominant species stability, leading to the decrease in temporal stability and the increase in resilience in response to the extreme flooding event. We also revealed that the change in species asynchrony was the dominant impact pathway determining the responses of resilience and temporal stability to flooding. Our results highlight that the alpine grassland experiencing multi-year drought may aggravate instability of community productivity to extreme climatic events by reducing species asynchrony.
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Affiliation(s)
- Yun L He
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Jin S Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Da S Tian
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Quan Quan
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Lin Jiang
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Fang F Ma
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Lu Yang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.,Research Center of Forest Management Engineering of State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Fang Y Zhang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Qing P Zhou
- Institute of Qinghai-Tibetan Plateau, Southwest University for Nationalities, Chengdu, China
| | - Shu L Niu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.,Departments of Ecology and Environment, University of Chinese Academy of Sciences, Beijing, China
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20
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Fang J, Xiong K, Chi Y, Song S, He C, He S. Research Advancement in Grassland Ecosystem Vulnerability and Ecological Resilience and Its Inspiration for Improving Grassland Ecosystem Services in the Karst Desertification Control. PLANTS (BASEL, SWITZERLAND) 2022; 11:1290. [PMID: 35631715 PMCID: PMC9145024 DOI: 10.3390/plants11101290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/23/2022] [Accepted: 05/06/2022] [Indexed: 12/05/2022]
Abstract
Karst desertification control of grasslands balances the ecological and economic benefits of ecological restoration and rural ecological animal husbandry development. In the context of global changes and intensified human activities, the fragility of grassland ecosystems under karst desertification control is becoming increasingly evident, and enhancing the ecological resilience and ecosystem services of grasslands is an issue that urgently needs to be addressed. In this paper, the CNKI literature, WOS core databases and Goolgle scholar were used as search sources, identifying 179 articles related to the study of grassland ecosystem vulnerability and ecological resilience. This research systematically reviewed the progress of grassland ecosystem vulnerability research and analyzed the relationship between grassland ecosystem services (GESs) and grassland ecosystem vulnerability and resilience. The direction of enhancing GESs in karst areas is indicated in terms of the reciprocal feedback, synergistic relationship, and mechanism of action of GESs, vulnerability, and resilience. It is also emphasized that the karst desertification area should provide an ecological foundation for the sustainable development of the regional environment around the supply-and-demand relationship of GESs, the trade-off synergy of service flow, and the enhancement of ecological resilience, thereby consolidating the effectiveness of karst desertification control, enhancing GESs, and helping rural revitalization.
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Affiliation(s)
- Jinzhong Fang
- School of Karst Science, Guizhou Normal University, Guiyang 550001, China; (J.F.); (Y.C.); (S.S.); (C.H.); (S.H.)
- State Engineering Technology Institute for Karst Desertification Control of China, 116 Baoshan North Road, Guiyang 550001, China
| | - Kangning Xiong
- School of Karst Science, Guizhou Normal University, Guiyang 550001, China; (J.F.); (Y.C.); (S.S.); (C.H.); (S.H.)
- State Engineering Technology Institute for Karst Desertification Control of China, 116 Baoshan North Road, Guiyang 550001, China
| | - Yongkuan Chi
- School of Karst Science, Guizhou Normal University, Guiyang 550001, China; (J.F.); (Y.C.); (S.S.); (C.H.); (S.H.)
- State Engineering Technology Institute for Karst Desertification Control of China, 116 Baoshan North Road, Guiyang 550001, China
| | - Shuzhen Song
- School of Karst Science, Guizhou Normal University, Guiyang 550001, China; (J.F.); (Y.C.); (S.S.); (C.H.); (S.H.)
- State Engineering Technology Institute for Karst Desertification Control of China, 116 Baoshan North Road, Guiyang 550001, China
| | - Cheng He
- School of Karst Science, Guizhou Normal University, Guiyang 550001, China; (J.F.); (Y.C.); (S.S.); (C.H.); (S.H.)
- State Engineering Technology Institute for Karst Desertification Control of China, 116 Baoshan North Road, Guiyang 550001, China
| | - Shuyu He
- School of Karst Science, Guizhou Normal University, Guiyang 550001, China; (J.F.); (Y.C.); (S.S.); (C.H.); (S.H.)
- State Engineering Technology Institute for Karst Desertification Control of China, 116 Baoshan North Road, Guiyang 550001, China
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21
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Shen JX, Zhang YJ, Maenpuen P, Zhang SB, Zhang L, Yang L, Tao LB, Yan PY, Zhang ZM, Li SQ, Yuan X, Kongjarat W, Kaewkamol S, Tinprabat P, Chen YJ. Response of four evergreen savanna shrubs to an incidence of extreme drought: high embolism resistance, branch shedding and maintenance of nonstructural carbohydrates. TREE PHYSIOLOGY 2022; 42:740-753. [PMID: 35020937 DOI: 10.1093/treephys/tpab150] [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: 05/18/2021] [Accepted: 10/20/2021] [Indexed: 06/14/2023]
Abstract
Extreme drought events are becoming frequent globally, resulting in widespread plant mortality and forest dieback. Although savanna vegetation cover ~20% of the earth's land area, their responses to extreme drought have been less studied than that of forests. Herein, we quantified branch dieback, individual mortality and the associated physiological responses of four evergreen shrubs (Tarenna depauperate Hutch., Maytenus esquirolii (H. Lév.) C.Y. Cheng, Murraya exotica L., Jasminum nudiflorum Lindl.) in a savanna ecosystem in Southwest China to an incidence of extreme drought during 2019 and 2020. We found that 80-100% of the individuals of these species exhibited branch dieback, whereas individual mortality was only found in T. depauperate (4.5%). All species showed high resistance to stem embolism (P50, water potential at 50% loss of hydraulic conductivity ranged from -5.62 to -8.6 MPa), whereas the stem minimum water potentials reached -7.6 to ca -10.0 MPa during the drought. The low water potential caused high native embolism levels (percentage loss of hydraulic conductivity (PLC) 23-65%) in terminal branches, and the remaining stems maintained 15-35% PLC at the end of the drought. Large within-individual variations in stem vulnerability to embolism were detected, and shedding of vulnerable branches could be a mechanism for shrubs to reduce water and carbon consumption. Overall, the content of total nonstructural carbohydrates (NSC) and their components in the stem were generally comparable to or higher than those in the rainy season in three of the four species. Because the leaves were turgor-less for most time during the drought, high NSC levels during the drought could be due to recycling of NSC from dead branches or translocation from roots. Our results suggest high tolerance of savanna shrub species to extreme drought, which could be facilitated by high embolism resistance in some stems and shedding of vulnerable branches to maintain individual water and carbon balance.
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Affiliation(s)
- Jing-Xian Shen
- Institute of Ecology and Geobotany, School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan 650091, China
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan 6663300, China
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME 04469, USA
| | - Phisamai Maenpuen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Shu-Bin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China
| | - Lan Zhang
- School of Geography and Ecotoursim, Southwest Forestry University, Panlong District, Kunming, Yunnan 650224, China
| | - Lin Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
| | - Lian-Bin Tao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
| | - Peng-Yun Yan
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
| | - Zhi-Ming Zhang
- Institute of Ecology and Geobotany, School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Shu-Qiong Li
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Xia Yuan
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Wanwalee Kongjarat
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Sasiwimol Kaewkamol
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Pimnara Tinprabat
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Ya-Jun Chen
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China
- Yuanjiang Savanna Ecosystem Research Station, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Yuanjiang, Yunnan 6663300, China
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Yunnan 666303, China
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22
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Qian J, Guo Z, Muraina TO, Te N, Griffin-Nolan RJ, Song L, Xu C, Yu Q, Zhang Z, Luo W. Legacy effects of a multi-year extreme drought on belowground bud banks in rhizomatous vs bunchgrass-dominated grasslands. Oecologia 2022; 198:763-771. [PMID: 35230515 DOI: 10.1007/s00442-022-05133-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 01/10/2022] [Indexed: 11/30/2022]
Abstract
Belowground bud banks play a crucial role in plant population regeneration, community dynamics, and functional responses of ecosystems to environmental change and disturbance. In mesic grasslands, belowground bud banks are largely resistant to short-term drought. However, the sensitivity of belowground bud banks to long-term extreme drought in semi-arid grasslands is less understood. We investigated the legacy effects of a four-year experimental drought (i.e., 66% reduction in growing season precipitation) on belowground bud density, aboveground shoot density, and the meristem limitation index (MLI; the ratio of bud to shoot density) in two semi-arid grasslands that differ in dominant grass species growth forms (i.e., rhizomatous vs. bunchgrasses). Measurements were made during the first recovery year following drought; thus, we report the legacy effects of drought on belowground bud banks. At the community level, drought reduced belowground bud density and aboveground shoot density with no change in MLI. However, drought had no significant influences on belowground buds, aboveground shoots and MLI of the dominant plant growth form in each community. The legacy effects of drought were largely dependent on plant community type and growth form. Specifically, bunchgrasses and bunchgrass-dominated communities were characterized by greater meristem limitation than rhizomatous grasses, likely due to their cluster/phalanx clonal growth. Overall, our study suggests bud banks may indeed be sensitive to long-term drought, although this depends on plant growth forms and community characteristics.
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Affiliation(s)
- Jianqiang Qian
- College of Forestry, Henan Agricultural University, Zhengzhou, 450002, China
| | - Ziyue Guo
- College of Forestry, Henan Agricultural University, Zhengzhou, 450002, China
| | - Taofeek O Muraina
- Department of Animal Health and Production, Oyo State College of Agriculture and Technology, P.M.B. 10, Igbo-Ora, Oyo State, Nigeria
| | - Niwu Te
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | | | - Lin Song
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Chong Xu
- National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Qiang Yu
- National Hulunber Grassland Ecosystem Observation and Research Station, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Zhiming Zhang
- College of Forestry, Henan Agricultural University, Zhengzhou, 450002, China.
| | - Wentao Luo
- Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
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23
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Wigley-Coetsee C, Strydom T, Govender D, Thompson DI, Govender N, Botha J, Simms C, Manganyi A, Kruger L, Venter J, Greaver C, Smit IP. Reflecting on research produced after more than 60 years of exclosures in the Kruger National Park. KOEDOE: AFRICAN PROTECTED AREA CONSERVATION AND SCIENCE 2022. [DOI: 10.4102/koedoe.v64i1.1674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Herbivores are a main driver of ecosystem patterns and processes in semi-arid savannas, with their effects clearly observed when they are excluded from landscapes. Starting in the 1960s, various herbivore exclosures have been erected in the Kruger National Park (KNP), for research and management purposes. These exclosures vary from very small (1 m2) to relatively large (almost 900 ha), from short-term (single growing season) to long-term (e.g. some of the exclosures were erected more than 60 years ago), and are located on different geologies and across a rainfall gradient. We provide a summary of the history and specifications of various exclosures. This is followed by a systematic overview of mostly peer-reviewed literature resulting from using KNP exclosures as research sites. These 75 articles cover research on soils, vegetation dynamics, herbivore exclusion on other faunal groups and disease. We provide general patterns and mechanisms in a synthesis section, and end with recommendations to increase research outputs and productivity for future exclosure experiments.Conservation Implications: Herbivore exclosures in the KNP have become global research platforms, that have helped in the training of ecologists, veterinarians and field biologists, and have provided valuable insights into savanna dynamics that would otherwise have been hard to gain. In an age of dwindling conservation funding, we make the case for the value added by exclosures and make recommendations for their continued use as learning tools in complex African savannas.
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24
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Grasslands Maintain Stability in Productivity Through Compensatory Effects and Dominant Species Stability Under Extreme Precipitation Patterns. Ecosystems 2021. [DOI: 10.1007/s10021-021-00706-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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Meng B, Li J, Maurer GE, Zhong S, Yao Y, Yang X, Collins SL, Sun W. Nitrogen addition amplifies the nonlinear drought response of grassland productivity to extended growing-season droughts. Ecology 2021; 102:e03483. [PMID: 34287849 DOI: 10.1002/ecy.3483] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/08/2021] [Accepted: 04/06/2021] [Indexed: 11/09/2022]
Abstract
Understanding the response of grassland production and carbon exchange to intra-annual variation in precipitation and nitrogen addition is critical for sustainable grassland management and ecosystem restoration. We introduced growing-season drought treatments of different lengths (15, 30, 45 and 60 d drought) by delaying growing-season precipitation in a long-term nitrogen addition experiment in a low diversity meadow steppe in northeast China. Response variables included aboveground biomass (AGB), ecosystem net carbon exchange (NEE), and leaf net carbon assimilation rate (A). In unfertilized plots drought decreased AGB by 13.7% after a 45-d drought and 31.7% after a 60-d drought (47.6% in fertilized plots). Progressive increases in the drought response of NEE were also observed. The effects of N addition on the drought response of productivity increased as drought duration increased, and these responses were a function of changes in AGB and biomass allocation, particularly root to shoot ratio. However, no significant effects of drought occurred in fertilized or unfertilized plots in the growing season a year after the experiment, N addition did limit the recovery of AGB from severe drought during the remainder of the current growing season. Our results imply that chronic N enrichment could exacerbate the effects of growing-season drought on grassland productivity caused by altered precipitation seasonality under climate change, but that these effects do not carry over to the next growing season.
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Affiliation(s)
- Bo Meng
- 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, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Junqin 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
| | - Gregory E Maurer
- Jornada Basin LTER Program, New Mexico State University, Las Cruces, New Mexico, 88003, USA
| | - Shangzhi Zhong
- College of Grassland Science, Grassland Agri-Husbandry Research Center, Qingdao Agricultural University, Qingdao, 255109, China
| | - Yuan Yao
- 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
| | - 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
| | - Scott L Collins
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - 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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26
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Zaplata MK, Nhabanga A, Stalmans M, Volpers T, Burkart M, Sperfeld E. Grasses cope with high‐contrast ecosystem conditions in the large outflow of the Banhine wetlands, Mozambique. Afr J Ecol 2020. [DOI: 10.1111/aje.12820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | - Erik Sperfeld
- Animal Ecology Zoological Institute and Museum University of Greifswald Greifswald Germany
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