1
|
Wang B, Zhu Y, Yang X, Shan D, Wang D, Tu Y, Shi Z, Indree T. Effects of plant diversity and community structure on ecosystem multifunctionality under different grazing potentials in the eastern Eurasian steppe. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 934:173128. [PMID: 38734106 DOI: 10.1016/j.scitotenv.2024.173128] [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: 12/17/2023] [Revised: 05/08/2024] [Accepted: 05/08/2024] [Indexed: 05/13/2024]
Abstract
Grazing potential represents the potential carrying capacity of steppe livestock production. Understanding the impact of changes in plant diversity and community structure on ecosystem multifunctionality (EMF) at different grazing potentials is crucial for the sustainable management of steppe ecosystems. We examined the associations between plant diversity, community structure, above-ground ecosystem multifunctionality (AEMF), and below-ground ecosystem multifunctionality (BEMF) at various grazing potentials. Our assessment employed generalized linear mixed-effects models and structural equation models to determine the impact of these factors on ecosystem multifunctionality. Our study results indicated that ecosystem multifunctionality differed depending on the level of grazing potential and decreased as grazing potential declined. The impact of plant diversity and community structure on above- and below-ground ecosystem multifunctionality varied. Plant diversity and community structure correlated more with AEMF than BEMF. Plant diversity had the most significant effect on EMF under high grazing potential, while community structure had the greatest effect on EMF under moderate and low grazing potential. These improve our understanding of the correlation between steppe plant diversity, community structure, and above- and below-ground ecosystem multifunctionality. This understanding is necessary to develop strategies to increase plant diversity or regulate community structure and the sustainability of steppes.
Collapse
Affiliation(s)
- Baizhu Wang
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Yuanjun Zhu
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China.
| | - Xiaohui Yang
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Dan Shan
- College of Agriculture and Forestry, Hulun Buir University, Hulun Buir, 021000, China
| | - Danyu Wang
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Ya Tu
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Zhongjie Shi
- Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China; Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China
| | - Tuvshintogtokh Indree
- Botanic Garden and Research Institute, Mongolian Academy of Sciences, Ulaanbaatar 13330, Mongolia
| |
Collapse
|
2
|
Slate ML, Antoninka A, Bailey L, Berdugo MB, Callaghan DA, Cárdenas M, Chmielewski MW, Fenton NJ, Holland-Moritz H, Hopkins S, Jean M, Kraichak BE, Lindo Z, Merced A, Oke T, Stanton D, Stuart J, Tucker D, Coe KK. Impact of changing climate on bryophyte contributions to terrestrial water, carbon, and nitrogen cycles. THE NEW PHYTOLOGIST 2024; 242:2411-2429. [PMID: 38659154 DOI: 10.1111/nph.19772] [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: 12/20/2023] [Accepted: 03/22/2024] [Indexed: 04/26/2024]
Abstract
Bryophytes, including the lineages of mosses, liverworts, and hornworts, are the second-largest photoautotroph group on Earth. Recent work across terrestrial ecosystems has highlighted how bryophytes retain and control water, fix substantial amounts of carbon (C), and contribute to nitrogen (N) cycles in forests (boreal, temperate, and tropical), tundra, peatlands, grasslands, and deserts. Understanding how changing climate affects bryophyte contributions to global cycles in different ecosystems is of primary importance. However, because of their small physical size, bryophytes have been largely ignored in research on water, C, and N cycles at global scales. Here, we review the literature on how bryophytes influence global biogeochemical cycles, and we highlight that while some aspects of global change represent critical tipping points for survival, bryophytes may also buffer many ecosystems from change due to their capacity for water, C, and N uptake and storage. However, as the thresholds of resistance of bryophytes to temperature and precipitation regime changes are mostly unknown, it is challenging to predict how long this buffering capacity will remain functional. Furthermore, as ecosystems shift their global distribution in response to changing climate, the size of different bryophyte-influenced biomes will change, resulting in shifts in the magnitude of bryophyte impacts on global ecosystem functions.
Collapse
Affiliation(s)
- Mandy L Slate
- Department of Evolution, Ecology & Organismal Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Anita Antoninka
- School of Forestry, Northern Arizona University, Flagstaff, AZ, 86005, USA
| | - Lydia Bailey
- School of Forestry, Northern Arizona University, Flagstaff, AZ, 86005, USA
| | - Monica B Berdugo
- Plant Ecology and Geobotany, Department of Biology, University of Marburg, Karl-von-Frisch Str. 8, 35043, Marburg, Germany
| | - Des A Callaghan
- Bryophyte Surveys Ltd, Almondsbury, South Gloucestershire, BS32 4DU, UK
| | - Mariana Cárdenas
- Department of Ecology Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | | | - Nicole J Fenton
- Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, J9X 5E4, Canada
| | - Hannah Holland-Moritz
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, 03824, USA
| | - Samantha Hopkins
- Department of Biology, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Mélanie Jean
- Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Bier Ekaphan Kraichak
- Department of Botany, Faculty of Science, Kasetsart University in Bangkok, Bangkok, 10900, Thailand
| | - Zoë Lindo
- Department of Biology, University of Western Ontario, London, ON, N6A 3K7, Canada
| | - Amelia Merced
- Department of Biology, University of Puerto Rico Río Piedras, San Juan, PR, 00925, USA
| | - Tobi Oke
- Wildlife Conservation Society & School of Environment & Sustainability, University of Saskatchewan, Saskatoon, SK, S7N 5C8, Canada
| | - Daniel Stanton
- Department of Ecology Evolution and Behavior, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Julia Stuart
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI, 49931, USA
- Mountain Planning Service Group, US Forest Service, Lakewood, CO, 80401, USA
| | - Daniel Tucker
- School of Environmental Studies, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Kirsten K Coe
- Department of Biology, Middlebury College, Middlebury, VT, 05753, USA
| |
Collapse
|
3
|
Liu C, Duan N, Chen X, Li X, Zhao N, Cao W, Li H, Liu B, Tan F, Zhao X, Li Q. Transcriptome Profiling and Chlorophyll Metabolic Pathway Analysis Reveal the Response of Nitraria tangutorum to Increased Nitrogen. PLANTS (BASEL, SWITZERLAND) 2023; 12:895. [PMID: 36840241 PMCID: PMC9962214 DOI: 10.3390/plants12040895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/04/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
To identify genes that respond to increased nitrogen and assess the involvement of the chlorophyll metabolic pathway and associated regulatory mechanisms in these responses, Nitraria tangutorum seedlings were subjected to four nitrogen concentrations (N0, N6, N36, and N60: 0, 6, 36, and 60 mmol·L-1 nitrogen, respectively). The N. tangutorum seedling leaf transcriptome was analyzed by high-throughput sequencing (Illumina HiSeq 4000), and 332,420 transcripts and 276,423 unigenes were identified. The numbers of differentially expressed genes (DEGs) were 4052 in N0 vs. N6, 6181 in N0 vs. N36, and 3937 in N0 vs. N60. Comparing N0 and N6, N0 and N36, and N0 and N60, we found 1101, 2222, and 1234 annotated DEGs in 113, 121, and 114 metabolic pathways, respectively, classified in the Kyoto Encyclopedia of Genes and Genomes database. Metabolic pathways with considerable accumulation were involved mainly in anthocyanin biosynthesis, carotenoid biosynthesis, porphyrin and chlorophyll metabolism, flavonoid biosynthesis, and amino acid metabolism. N36 increased δ-amino levulinic acid synthesis and upregulated expression of the magnesium chelatase H subunit, which promoted chlorophyll a synthesis. Hence, N36 stimulated chlorophyll synthesis rather than heme synthesis. These findings enrich our understanding of the N. tangutorum transcriptome and help us to research desert xerophytes' responses to increased nitrogen in the future.
Collapse
Affiliation(s)
- Chenggong Liu
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Na Duan
- Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou 015200, China
- National Long-Term Scientific Research Base of Ulan Buh Desert Comprehensive Control, National Forestry and Grassland Administration, Dengkou 015200, China
| | - Xiaona Chen
- Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou 015200, China
- National Long-Term Scientific Research Base of Ulan Buh Desert Comprehensive Control, National Forestry and Grassland Administration, Dengkou 015200, China
| | - Xu Li
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Naqi Zhao
- Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou 015200, China
- National Long-Term Scientific Research Base of Ulan Buh Desert Comprehensive Control, National Forestry and Grassland Administration, Dengkou 015200, China
| | - Wenxu Cao
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Huiqing Li
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Bo Liu
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Fengsen Tan
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Xiulian Zhao
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| | - Qinghe Li
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Beijing 100091, China
| |
Collapse
|
4
|
Taylor AF, Freitag TE, Robinson L, White D, Hedley P, Britton AJ. Nitrogen deposition and temperature structure fungal communities associated with alpine moss-sedge heath in the UK. FUNGAL ECOL 2022. [DOI: 10.1016/j.funeco.2022.101191] [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]
|
5
|
Zhang Y, Jin Y, Xu J, He H, Tao Y, Yang Z, Bai Y. Effects of exogenous N and endogenous nutrients on alpine tundra litter decomposition in an area of high nitrogen deposition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 805:150388. [PMID: 34818765 DOI: 10.1016/j.scitotenv.2021.150388] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
The effects of N deposition on the C and N cycles via altered litter decomposition rates are an important aspect of global environmental change. The Changbai Mountain region experienced a high N deposition (2.7 g·m-2·year-1 in 2015) and corresponding expansion of Deyeuxia purpurea into the alpine tundra, resulting in changes in endogenous nutrients. However, the relative contributions of the N deposition and endogenous litter nutrients to litter decompositions remain unclear. Therefore, a 5-year N addition and 2-year litter decomposition experiments were conducted. Exogenous N reduced the remaining litter mass of Rhododendron aureum at the early stage (30-240 d) by promoting soluble sugar release, and increased it at the late stage (360-720 d) by suppressing lignin release and decreasing soil microbial community and enzyme activity. A higher proportion of D. purpurea litter (representing higher N, lower lignin, and C:N ratio) decreased remaining litter mass and increased net N release. Exogenous N decreased decomposition rate from 0.32 to 0.21 and net N release from 34% to 24%, whereas litter compositions increased decomposition rates from 0.32 to 0.69 and net litter N release from 34% to 69%. Endogenous litter nutrients directly explained 62% and 40% of the litter decomposition and net N release variables, respectively, whereas exogenous N indirectly explained 12% and 9%, respectively. Thus, we infer that the reductions in C and N storage following D. purpurea expansion may offset the increases of C and N storage under N deposition and the expansion of D. purpurea has a potential long-term negative impact on the ability of tundra plants to sequester C and N in the alpine tundra of the Changbai Mountains. These findings highlight how shifting plant expansion, through changes endogenous nutrients, can influence tundra litter decomposition and C and N storage responses to N deposition.
Collapse
Affiliation(s)
- Yingjie Zhang
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Yinghua Jin
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Jiawei Xu
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Hongshi He
- School of Natural Resources, University of Missouri, Columbia, MO 65211, USA.
| | - Yan Tao
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Zhipeng Yang
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| | - Yunyu Bai
- Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun 130024, China.
| |
Collapse
|
6
|
Alday J, O'Reilly J, Rose RJ, Marrs RH. Effects of long-term removal of sheep-grazing in a series of British upland plant communities: Insights from plant species composition and traits. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 759:143508. [PMID: 33218809 DOI: 10.1016/j.scitotenv.2020.143508] [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: 08/24/2020] [Revised: 10/14/2020] [Accepted: 10/26/2020] [Indexed: 06/11/2023]
Abstract
Environmental and management pressures are considered a threat for preserving plant communities worldwide. Identification of long-term impacts of changing management practices on plant community composition must, therefore, be a major priority to ensure improvement in conservation value. Land abandonment/wilding is one topical area where there is little available information on long-term impacts. To address this, here, we describe plant species compositional change over relatively long-time scales in a range of four British upland communities (high-level grasslands, intermediate grasslands, blanket bogs and high-level bogs) and its relationships with a series of life-history and plant trait variables. Our aims were to determine whether the business-as-usual sheep grazing practice was maintaining these communities, and if grazing was to be removed as part of abandonment/wilding strategies, would there be a conservation benefit. We used a series of long-term experimental grazing-exclosure studies at twelve sites (>40 years) on the Moor House National Nature Reserve in northern England. Each site consisted of paired plots; i.e. sheep-grazed versus ungrazed. Our results showed that there was relatively little change in dominant plant species with most change occurring within sub-dominant species. Similarly, different temporal responses in plant species richness were detected between the experiments (richness was reduced in three experiments, only one increased). In any case, the vegetation temporal trajectories were moving in similar direction in grazed and ungrazed plots at most sites. Interestingly, blanket bog experiments showed a clear compositional convergence for both grazed and ungrazed plots, although, the between-site differences related to a combination of elevation and past burning testament. Finally, the bryophytes (especially liverworts) and lichens were the groups that contributed most to the reductions in species richness. Moreover, implementation of a no-stock grazing strategy under a land abandonment/wilding approach will not bring about much plant change in the short-term in the plant communities studied here.
Collapse
Affiliation(s)
- Josu Alday
- School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP, UK; Joint Research Unit CTFC - AGROTECNIO, Av. Alcalde Rovira Roure 191, E25198 Lleida, Spain; Department of Crop and Forest Sciences, University of Lleida, Av. Alcalde Rovira Roure 191, E25198 Lleida, Spain
| | - John O'Reilly
- Ptyxis Ecology, Railway Cottages, Lambley, Northumberland CA8 7LL, UK.
| | - Rob J Rose
- CEH Lancaster, Centre for Ecology & Hydrology, Bailrigg, Lancaster LA1 4AP, UK
| | - Rob H Marrs
- School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP, UK.
| |
Collapse
|
7
|
van Paassen JG, Britton AJ, Mitchell RJ, Street LE, Johnson D, Coupar A, Woodin SJ. Legacy effects of nitrogen and phosphorus additions on vegetation and carbon stocks of upland heaths. THE NEW PHYTOLOGIST 2020; 228:226-237. [PMID: 32432343 DOI: 10.1111/nph.16671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
Soil carbon (C) pools and plant community composition are regulated by nitrogen (N) and phosphorus (P) availability. Atmospheric N deposition impacts ecosystem C storage, but the direction of response varies between systems. Phosphorus limitation may constrain C storage response to N, hence P application to increase plant productivity and thus C sequestration has been suggested. We revisited a 23-yr-old field experiment where N and P had been applied to upland heath, a widespread habitat supporting large soil C stocks. At 10 yr after the last nutrient application we quantified long-term changes in vegetation composition and in soil and vegetation C and P stocks. Nitrogen addition, particularly when combined with P, strongly influenced vegetation composition, favouring grasses over Calluna vulgaris, and led to a reduction in vegetation C stocks. However, soil C stocks did not respond to nutrient treatments. We found 40% of the added P had accumulated in the soil. This study showed persistent effects of N and N + P on vegetation composition, whereas effects of P alone were small and showed recovery. We found no indication that P application could mitigate the effects of N on vegetation or increase C sequestration in this system.
Collapse
Affiliation(s)
- José G van Paassen
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Andrea J Britton
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Ruth J Mitchell
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Lorna E Street
- School of Geosciences, University of Edinburgh, Edinburgh, EH9 3FF, UK
| | - David Johnson
- Department of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9PT, UK
| | - Andrew Coupar
- Scottish Natural Heritage, The Links, Golspie, KW10 6UB, UK
| | - Sarah J Woodin
- School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 3UU, UK
| |
Collapse
|
8
|
Ewing SR, Baxter A, Wilson JD, Hayhow DB, Gordon J, Thompson DBA, Whitfield DP, van der Wal R. Clinging on to alpine life: Investigating factors driving the uphill range contraction and population decline of a mountain breeding bird. GLOBAL CHANGE BIOLOGY 2020; 26:3771-3787. [PMID: 32350939 DOI: 10.1111/gcb.15064] [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: 07/16/2019] [Revised: 01/16/2020] [Accepted: 02/01/2020] [Indexed: 06/11/2023]
Abstract
Climate change and anthropogenic nitrogen deposition are widely regarded as important drivers of environmental change in alpine habitats. However, due to the difficulties working in high-elevation mountain systems, the impacts of these drivers on alpine breeding species have rarely been investigated. The Eurasian dotterel (Charadrius morinellus) is a migratory wader, which has been the subject of uniquely long-term and spatially widespread monitoring effort in Scotland, where it breeds in alpine areas in dwindling numbers. Here we analyse data sets spanning three decades, to investigate whether key potential drivers of environmental change in Scottish mountains (snow lie, elevated summer temperatures and nitrogen deposition) have contributed to the population decline of dotterel. We also consider the role of rainfall on the species' wintering grounds in North Africa. We found that dotterel declines-in both density and site occupancy of breeding males-primarily occurred on low and intermediate elevation sites. High-elevation sites mostly continued to be occupied, but males occurred at lower densities in years following snow-rich winters, suggesting that high-elevation snow cover displaced dotterel to lower sites. Wintering ground rainfall was positively associated with densities of breeding males two springs later. Dotterel densities were reduced at low and intermediate sites where nitrogen deposition was greatest, but not at high-elevation sites. While climatic factors explained variation in breeding density between years, they did not seem to explain the species' uphill retreat and decline. We cannot rule out the possibility that dotterel have increasingly settled on higher sites previously unavailable due to extensive snow cover, while changes associated with nitrogen deposition may also have rendered lower lying sites less suitable for breeding. Causes of population and range changes in mountain-breeding species are thus liable to be complex, involving multiple anthropogenic drivers of environmental change acting widely across annual and migratory life cycles.
Collapse
Affiliation(s)
- Steven R Ewing
- RSPB Centre for Conservation Science, RSPB Scotland, Edinburgh, UK
| | - Alistair Baxter
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Jeremy D Wilson
- RSPB Centre for Conservation Science, RSPB Scotland, Edinburgh, UK
| | - Daniel B Hayhow
- RSPB Centre for Conservation Science, RSPB, The Lodge, Bedfordshire, UK
| | - James Gordon
- RSPB Centre for Conservation Science, RSPB Scotland, Edinburgh, UK
| | | | | | - René van der Wal
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| |
Collapse
|
9
|
Liu X, Wang Z, Li X, Rousk K, Bao W. High nitrogen resorption efficiency of forest mosses. ANNALS OF BOTANY 2020; 125:557-563. [PMID: 31840155 PMCID: PMC7102953 DOI: 10.1093/aob/mcz199] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND AIMS Nutrient resorption from senescing tissue is a key mechanism for plants to conserve nutrients, and can affect the nutrient dynamics of ecosystems. Yet, our limited knowledge of nitrogen (N) resorption and release from mosses hampers our understanding of the role of mosses as N sources and, thereby, N cycling in moss-dominated ecosystems. The aims of this study were to estimate N resorption efficiency (NRE) of two moss species, identify the pathways of N release from the mosses and to provide a better understanding of N cycling and budgeting strategies of mosses. METHODS The dynamics of N allocation along annual moss segments of two dominant moss species (Actinothuidium hookeri and Hylocomium splendens) were assessed in old-growth fir forests using an in situ15N tracer experiment. KEY RESULTS The NRE of A. hookeri and H. splendens was 61 and 52 %, respectively. While the mosses lost 23 and 33 % N from live tissues via leaching, 15 and 14 % of N remained in senesced tissues (>3 years old) in A. hookeri and H. splendens, respectively. CONCLUSIONS Both mosses resorbed the majority of their tissue N, but a considerable amount of N was lost from live segments. Our results highlight the crucial role mosses play as N sinks in ecosystems, since N retention (resorbed and sequestered in senescent tissue) outweighed N loss via leaching. However, the sink strength depends on temperature and precipitation, which will change in a future climate. The values for NRE, leaching, etc. estimated here can help improve biogeochemical models aiming to complete N budgets for moss-abundant ecosystems.
Collapse
Affiliation(s)
- Xin Liu
- Chinese Academy of Sciences (CAS) Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Zhe Wang
- Chinese Academy of Sciences (CAS) Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Xiaoming Li
- Chinese Academy of Sciences (CAS) Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Kathrin Rousk
- Department of Biology, Terrestrial Ecology Section, University of Copenhagen, Copenhagen, Denmark
- Center for Permafrost (CENPERM), University of Copenhagen, Copenhagen, Denmark
| | - Weikai Bao
- Chinese Academy of Sciences (CAS) Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| |
Collapse
|
10
|
Wang X, Yuan W, Feng X, Wang D, Luo J. Moss facilitating mercury, lead and cadmium enhanced accumulation in organic soils over glacial erratic at Mt. Gongga, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 254:112974. [PMID: 31376600 DOI: 10.1016/j.envpol.2019.112974] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/26/2019] [Accepted: 07/26/2019] [Indexed: 06/10/2023]
Abstract
Moss is usually as an initial colonizer in alpine glacier retreated regions. We hypothesized that moss can significantly facilitate the toxic metals accumulation in alpine ecosystems based on its strong ability of absorption and the role in soil development. Hence, we investigated the trace element pool sizes and enrichment factors, especially for mercury (Hg) by using the Hg isotopic compositions to determine the source contributions in a moss-dominated ecosystem over glacial erratic in Eastern Tibetan Plateau. Results show that Hg, lead (Pb) and cadmium (Cd) are highly enriched in organic soils. Specifically, Cd concentration is 5-20 times higher than the safety limit of the acid soil (pH ≤ 5.5) in China. Atmospheric depositions dominantly contribute to the Pb and Cd sources in organic soils, and followed by the moraine particles influences. The lowering pH in organic soils increasing with glacial retreated time results in the desorption of Cd in organic soils. Atmospheric Hg0 uptake by moss predominantly contributes to the Hg sources in organic soils. The average Pb accumulation rate over last 125-year is about 5.6 ± 1.0 mg m-2 yr-1, and for Cd is 0.4 ± 0.1 mg m-2 yr-1, and for Hg0 is 27.6 ± 3.2 μg m-2 yr-1. These elevated accumulation rates are caused by the high moss biomass and elevated atmospheric Hg, Pb and Cd pollution levels in China and neighbouring regions. Our study indicates that the moss not only as the bioindicator, but also plays an important role in the hazardous metal biogeochemical cycling in alpine regions.
Collapse
Affiliation(s)
- Xun Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Wei Yuan
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China.
| | - Dingyong Wang
- College of Resources and Environment, Southwest University, Chongqing, 400715, China
| | - Ji Luo
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences & Ministry of Water Conservancy, Chengdu, 610041, China
| |
Collapse
|
11
|
Britton AJ, Gibbs S, Fisher JM, Helliwell RC. Impacts of nitrogen deposition on carbon and nitrogen cycling in alpine Racomitrium heath in the UK and prospects for recovery. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 254:112986. [PMID: 31394340 DOI: 10.1016/j.envpol.2019.112986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 06/10/2023]
Abstract
Deposition of reactive nitrogen (N) is a major threat to terrestrial ecosystems associated with impacts on ecosystem properties and functions including carbon (C) and nutrient stocks, soil water quality and nutrient retention. In the oceanic-alpine Racomitrium heath habitat, N deposition is associated with moss mat degradation and a shift from bryophyte to graminoid dominance. To investigate the effects of moss mat decline on C and N stocks and fluxes, we collected Racomitrium heath vegetation/soil cores from sites along a gradient of N deposition in the UK. Cores were maintained under controlled conditions and exposed to scenarios of current (8-40 kg N ha-1 y-1), reduced (8 kg N ha-1 y-1) and elevated (50 kg N ha-1 y-1) N deposition. Cores from high N deposition sites had smaller aboveground C and N stocks and, under current conditions, leached large amounts of inorganic N and had low soil water pH compared with low N deposition sites. With reduced N deposition there was evidence for rapid recovery of soil water quality in terms of reduced N leaching and small increases in pH. Under high N deposition, cores from low N deposition sites retained much of the applied N while those with a history of high N deposition leached large amounts of inorganic N. Carbon fluxes in soil water and net CO2 fluxes varied according to core source site but were not affected by the N deposition scenarios. We conclude that C and N stocks and cycling in Racomitrium heath are strongly affected by long-term exposure to N deposition but that soil water quality may improve rapidly, if N deposition rates are reduced. The legacy of N deposition impacts on moss mat cover and vegetation composition however, mean that the ecosystem remains sensitive to future pulses in N input.
Collapse
Affiliation(s)
- Andrea J Britton
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
| | - Sheila Gibbs
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Julia M Fisher
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | | |
Collapse
|
12
|
Payne RJ, Campbell C, Britton AJ, Mitchell RJ, Pakeman RJ, Jones L, Ross LC, Stevens CJ, Field C, Caporn SJM, Carroll J, Edmondson JL, Carnell EJ, Tomlinson S, Dore AJ, Dise N, Dragosits U. What is the most ecologically-meaningful metric of nitrogen deposition? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 247:319-331. [PMID: 30685673 DOI: 10.1016/j.envpol.2019.01.059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/11/2019] [Accepted: 01/16/2019] [Indexed: 06/09/2023]
Abstract
Nitrogen (N) deposition poses a severe risk to global terrestrial ecosystems, and managing this threat is an important focus for air pollution science and policy. To understand and manage the impacts of N deposition, we need metrics which accurately reflect N deposition pressure on the environment, and are responsive to changes in both N deposition and its impacts over time. In the UK, the metric typically used is a measure of total N deposition over 1-3 years, despite evidence that N accumulates in many ecosystems and impacts from low-level exposure can take considerable time to develop. Improvements in N deposition modelling now allow the development of metrics which incorporate the long-term history of pollution, as well as current exposure. Here we test the potential of alternative N deposition metrics to explain vegetation compositional variability in British semi-natural habitats. We assembled 36 individual datasets representing 48,332 occurrence records in 5479 quadrats from 1683 sites, and used redundancy analyses to test the explanatory power of 33 alternative N metrics based on national pollutant deposition models. We find convincing evidence for N deposition impacts across datasets and habitats, even when accounting for other large-scale drivers of vegetation change. Metrics that incorporate long-term N deposition trajectories consistently explain greater compositional variance than 1-3 year N deposition. There is considerable variability in results across habitats and between similar metrics, but overall we propose that a thirty-year moving window of cumulative deposition is optimal to represent impacts on plant communities for application in science, policy and management.
Collapse
Affiliation(s)
- Richard J Payne
- Environment and Geography, University of York, York, YO105DD, UK; Scottish Environmental Protection Agency, Strathallan House, Stirling, FK94TF, UK.
| | - Claire Campbell
- Scottish Environmental Protection Agency, Strathallan House, Stirling, FK94TF, UK
| | - Andrea J Britton
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Ruth J Mitchell
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Robin J Pakeman
- The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
| | - Laurence Jones
- Centre for Ecology and Hydrology, Environment Centre Wales, Bangor, LL572UW, UK
| | - Louise C Ross
- Institute of Biological and Environmental Sciences, University of Aberdeen, St Machar Drive, Aberdeen, AB243UU, UK
| | - Carly J Stevens
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA14YQ, UK
| | - Christopher Field
- School of Science and the Environment, Manchester Metropolitan University, Chester St, Manchester, M15GD, UK
| | - Simon J M Caporn
- School of Science and the Environment, Manchester Metropolitan University, Chester St, Manchester, M15GD, UK
| | - Jacky Carroll
- School of Science and the Environment, Manchester Metropolitan University, Chester St, Manchester, M15GD, UK
| | - Jill L Edmondson
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Sheffield, S10 2TN, UK
| | - Edward J Carnell
- Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH260QB, UK
| | - Sam Tomlinson
- Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH260QB, UK
| | - Anthony J Dore
- Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH260QB, UK
| | - Nancy Dise
- Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH260QB, UK
| | - Ulrike Dragosits
- Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH260QB, UK
| |
Collapse
|