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Wang Q, Wang R, Yang X, Anderson NJ, Kong L. Interactive effects of climate-atmospheric cycling on aquatic communities and ecosystem shifts in mountain lakes of southeastern Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169825. [PMID: 38199353 DOI: 10.1016/j.scitotenv.2023.169825] [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: 09/13/2023] [Revised: 12/28/2023] [Accepted: 12/30/2023] [Indexed: 01/12/2024]
Abstract
Recent climate warming and atmospheric reactive nitrogen (Nr) deposition are affecting a broad spectrum of physical, ecological and human systems that may be irreversible on a century time scale and have the potential to cause regime shifts in ecological systems. These changes may alter the limnological conditions with important but still unclear effects on lake ecosystems. We present changes in cladoceran with comparisons to diatom assemblages over the past ~200 years from high-resolution, well-dated sediment cores retrieved from six high mountain lakes in the southeastern (SE) margin of the Tibetan Plateau. Our findings suggest that warming and the exponential increase of atmospheric Nr deposition are the major drivers of ecological regime changes. Shifts in cladoceran and diatom communities in high alpine lakes began over a century ago and intensified since 1950 CE, indicating a regional-scale response to anthropogenic climate warming. Zooplankton in the forest lakes showed asynchronous trajectories, with increased Nr deposition as a significant explanatory factor. Forest lakes with higher dissolved organic carbon (DOC) concentrations partially buffered the impacts of Nr deposition with little structural change, while lakes with low DOC display symptoms of resilience loss related to Nr deposition. Biological community compositional turnover in subalpine lakes has shown marked shifts, equivalent to those of low-elevation lakes strongly affected by direct human impacts. This suggests that local effects override climatic forcing and that lake basin features modified by anthropogenic activity act as basin-specific filters of common forcing. Our results indicate that snow and glacial meltwaters along with nutrient enrichment related to climate warming and atmospheric Nr deposition, represent major threats for lake ecosystems, even in remote areas. We reveal that climate and atmospheric contaminants will further impact ecological conditions and alter aquatic food webs in higher altitude biomes if climate and anthropogenic forcing continue.
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Affiliation(s)
- Qian Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Nanjing 211135, China
| | - Rong Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Xiangdong Yang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Nanjing 211135, China.
| | | | - Lingyang Kong
- Provincial Key Laboratory of Plateau Geographical Processes and Environmental Change, Faculty of Geography, Yunnan Normal University, Kunming 650500, China
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Shah AA, Hotaling S, Lapsansky AB, Malison RL, Birrell JH, Keeley T, Giersch JJ, Tronstad LM, Woods HA. Warming undermines emergence success in a threatened alpine stonefly: A multi‐trait perspective on vulnerability to climate change. Funct Ecol 2023. [DOI: 10.1111/1365-2435.14284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- Alisha A. Shah
- Division of Biological Sciences University of Montana Missoula Montana USA
- W.K. Kellogg Biological Station, Department of Integrative Biology Michigan State University Hickory Corners Michigan USA
| | - Scott Hotaling
- School of Biological Sciences Washington State University Pullman Washington USA
- Department of Watershed Sciences Utah State University Logan Utah USA
| | - Anthony B. Lapsansky
- Division of Biological Sciences University of Montana Missoula Montana USA
- Department of Zoology University of British Columbia Vancouver British Columbia Canada
| | - Rachel L. Malison
- Flathead Lake Biological Station University of Montana Missoula Montana USA
| | - Jackson H. Birrell
- Division of Biological Sciences University of Montana Missoula Montana USA
| | - Tylor Keeley
- Division of Biological Sciences University of Montana Missoula Montana USA
| | - J. Joseph Giersch
- Flathead Lake Biological Station University of Montana Missoula Montana USA
| | - Lusha M. Tronstad
- Wyoming Natural Diversity Database University of Wyoming Laramie Wyoming USA
| | - H. Arthur Woods
- Division of Biological Sciences University of Montana Missoula Montana USA
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3
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Lü J, Wang S, Liu B, Song X. Spatiotemporal heterogeneity of nitrogen transformation potentials in a freshwater estuarine system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 859:160335. [PMID: 36414069 DOI: 10.1016/j.scitotenv.2022.160335] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/31/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
Under the influence of water diversion, the microbial community composition of estuarine waters and sediments might have complex spatiotemporal variations. Microbial interactions with N are significant for lake water quality. Therefore, the largest lake receiving seasonal water diversion in the North China Plain was selected as the study area. Based on 16S rRNA high-throughput sequencing and metagenomic sequencing techniques, this study analysed temporal (June-December) and spatial (estuary-pelagic zone) changes in the microbial community and functional gene composition of water and sediment. The results showed that the water microbial community composition had temporality, while sediment microbes had spatiality. The main causes of temporality in the aquatic microbial community were temperature and nitrate-N concentration, while those of sediment were flow velocity and N content. Additionally, there were complex interactions between microbial communities and N. In water, temporal variation in the relative abundance of N-related functional genes might have indirectly contributed to inorganic N composition in June (nitrite-N > ammonia-N > nitrate-N) and August (nitrite-N > nitrate-N > ammonia-N). High nitrate-N concentrations in December influenced the microbial community composition. In sediment, the estuary had higher N functional genes than the pelagic estuary, creating a relatively active N cycle and reducing total N levels in the estuary. This study revealed a potentially overlooked N sink and a flow velocity threshold that has great impacts on microbial community composition. This research contributes to a deeper understanding of the estuarine N cycle under the influence of water diversions, with implications for the calculation of global N balances and the management of lake water environments.
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Affiliation(s)
- Jiali Lü
- Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050021, China; Sino-Danish College of University of Chinese Academy of Sciences, Beijing 101408, China; Sino-Danish Centre for Education and Research, Beijing 101408, China; Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen 999017, Denmark
| | - Shiqin Wang
- Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050021, China; Xiongan Institute of Innovation, Chinese Academy of Science, China.
| | - Binbin Liu
- Key Laboratory of Agricultural Water Resources, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050021, China; Xiongan Institute of Innovation, Chinese Academy of Science, China
| | - Xianfang Song
- Sino-Danish College of University of Chinese Academy of Sciences, Beijing 101408, China; Sino-Danish Centre for Education and Research, Beijing 101408, China; Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
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Ding Y, Pan B, Zhao X, Zhao G, Han X, Li M. Will a heavy sediment load affect responses of phytoplankton functional groups to aquatic environmental changes in different water body types? THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 837:155863. [PMID: 35568163 DOI: 10.1016/j.scitotenv.2022.155863] [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: 11/23/2021] [Revised: 05/07/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Sediment, as a natural component of rivers, directly affects the abundance and function of phytoplankton by altering water physicochemical properties. Despite mounting evidence for the sensitivity of phytoplankton to environmental factors, the responses of phytoplankton functional groups to complex environmental changes in rivers with a heavy sediment load are still poorly understood. Herein, the effectiveness of phytoplankton functional groups was evaluated as an indicator of aquatic environmental changes in a heavily sediment-laden river. Samples were collected from 44 sites (22 free-flowing river sections and 22 man-made reservoir sections) with a mean annual sediment concentration of 4.69 kg m-3 in the Yellow River, China. A total of 31 phytoplankton functional groups were classified during spring (April-May) and autumn (September-October) in 2019. Groups C, MP, and D, which are well adapted to strong water disturbances and turbid habitats, showed distinct advantages over other groups. Despite no significant differences in many environmental variables between the river and reservoir sections, these variables (especially nitrogen nutrients) had remarkable effects on the phytoplankton community structure. The phytoplankton functional groups were sensitive to environmental changes even under sediment interference, although geo-climatic variables also exhibited non-trivial effects. The mean niche breadth of the abundant taxa (river: 11.16; reservoir: 7.93) was higher than that of the rare taxa (river: 5.64; reservoir: 4.86) in different water bodies. Thus, growth and diffusion of the abundant taxa played paramount roles in maintaining ecosystem stability. The results indicate that, in a large-scale sediment-laden river, phytoplankton functional groups can effectively indicate changes in the aquatic environment of either a free-flowing river or a man-made reservoir.
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Affiliation(s)
- Yitong Ding
- State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China
| | - Baozhu Pan
- State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China.
| | - Xiaohui Zhao
- State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China
| | - Gengnan Zhao
- State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China.
| | - Xu Han
- State Key Laboratory of Eco-hydraulic in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China
| | - Ming Li
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
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Burpee BT, Saros JE, Nanus L, Baron J, Brahney J, Christianson KR, Ganz T, Heard A, Hundey B, Koinig KA, Kopáček J, Moser K, Nydick K, Oleksy I, Sadro S, Sommaruga R, Vinebrooke R, Williams J. Identifying factors that affect mountain lake sensitivity to atmospheric nitrogen deposition across multiple scales. WATER RESEARCH 2022; 209:117883. [PMID: 34864346 DOI: 10.1016/j.watres.2021.117883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 11/14/2021] [Accepted: 11/15/2021] [Indexed: 06/13/2023]
Abstract
Increased nitrogen (N) deposition rates over the past century have affected both North American and European mountain lake ecosystems. Ecological sensitivity of mountain lakes to N deposition varies, however, because chemical and biological responses are modulated by local watershed and lake properties. We evaluated predictors of mountain lake sensitivity to atmospheric N deposition across North American and European mountain ranges and included as response variables dissolved inorganic N (DIN = NNH4+ + NNO3-) concentrations and phytoplankton biomass. Predictors of these responses were evaluated at three different spatial scales (hemispheric, regional, subregional) using regression tree, random forest, and generalized additive model (GAM) analysis. Analyses agreed that Northern Hemisphere mountain lake DIN was related to N deposition rates and smaller scale spatial variability (e.g., regional variability between North American and European lakes, and subregional variability between mountain ranges). Analyses suggested that DIN, N deposition, and subregional variability were important for Northern Hemisphere mountain lake phytoplankton biomass. Together, these findings highlight the need for finer-scale, subregional analyses (by mountain range) of lake sensitivity to N deposition. Subregional analyses revealed differences in predictor variables of lake sensitivity. In addition to N deposition rates, lake and watershed features such as land cover, bedrock geology, maximum lake depth (Zmax), and elevation were common modulators of lake DIN. Subregional phytoplankton biomass was consistently positively related with total phosphorus (TP) in Europe, while North American locations showed variable relationships with N or P. This study reveals scale-dependent watershed and lake characteristics modulate mountain lake ecological responses to atmospheric N deposition and provides important context to inform empirically based management strategies.
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Affiliation(s)
- Benjamin T Burpee
- Climate Change Institute and School of Biology and Ecology, University of Maine, Orono, ME, USA.
| | - Jasmine E Saros
- Climate Change Institute and School of Biology and Ecology, University of Maine, Orono, ME, USA
| | - Leora Nanus
- Department of Geography and Environment, San Francisco State University, San Francisco, CA 80526, USA
| | - Jill Baron
- Natural Resource Ecology Laboratory, U.S. Geological Survey, Colorado State University, Fort Collins, CO 80526, USA
| | - Janice Brahney
- Department of Watershed Sciences, Utah State University, Logan, UT, USA
| | - Kyle R Christianson
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA
| | - Taylor Ganz
- School of the Environment, Yale University, New Haven, CT, USA
| | - Andi Heard
- Sierra Nevada Network, National Park Service, Three Rivers, CA, USA
| | - Beth Hundey
- Centre for Teaching and Learning, The University of Western Ontario, London, Ontario, Canada
| | - Karin A Koinig
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Jiří Kopáček
- Biology Centre CAS, Institute of Hydrobiology, České Budějovice, Czech Republic
| | - Katrina Moser
- Department of Geography, The University of Western Ontario, London, Ontario, Canada
| | - Koren Nydick
- Sequoia and Kings Canyon National Parks, Three Rivers, CA, USA; Rocky Mountain National Park, Estes Park, CO, USA
| | | | - Steven Sadro
- Environmental Science and Policy, University of California Davis, Davis, CA, USA
| | - Ruben Sommaruga
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Rolf Vinebrooke
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Jason Williams
- Idaho Department of Environmental Quality, Lewiston Regional Office, Lewiston, ID, USA
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Oleksy IA, Jones SE, Solomon CT. Hydrologic Setting Dictates the Sensitivity of Ecosystem Metabolism to Climate Variability in Lakes. Ecosystems 2021. [DOI: 10.1007/s10021-021-00718-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractGlobal change is influencing production and respiration in ecosystems across the globe. Lakes in particular are changing in response to climatic variability and cultural eutrophication, resulting in changes in ecosystem metabolism. Although the primary drivers of production and respiration such as the availability of nutrients, light, and carbon are well known, heterogeneity in hydrologic setting (for example, hydrological connectivity, morphometry, and residence) across and within regions may lead to highly variable responses to the same drivers of change, complicating our efforts to predict these responses. We explored how differences in hydrologic setting among lakes influenced spatial and inter annual variability in ecosystem metabolism, using high-frequency oxygen sensor data from 11 lakes over 8 years. Trends in mean metabolic rates of lakes generally followed gradients of nutrient and carbon concentrations, which were lowest in seepage lakes, followed by drainage lakes, and higher in bog lakes. We found that while ecosystem respiration (ER) was consistently higher in wet years in all hydrologic settings, gross primary production (GPP) only increased in tandem in drainage lakes. However, interannual rates of ER and GPP were relatively stable in drainage lakes, in contrast to seepage and bog lakes which had coefficients of variation in metabolism between 22–32%. We explored how the geospatial context of lakes, including hydrologic residence time, watershed area to lake area, and landscape position influenced the sensitivity of individual lake responses to climatic variation. We propose a conceptual framework to help steer future investigations of how hydrologic setting mediates the response of metabolism to climatic variability.
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Climate Change, Ecosystem Processes and Biological Diversity Responses in High Elevation Communities. CLIMATE 2021. [DOI: 10.3390/cli9050087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The populations, species, and communities in high elevation mountainous regions at or above tree line are being impacted by the changing climate. Mountain systems have been recognized as both resilient and extremely threatened by climate change, requiring a more nuanced understanding of potential trajectories of the biotic communities. For high elevation systems in particular, we need to consider how the interactions among climate drivers and topography currently structure the diversity, species composition, and life-history strategies of these communities. Further, predicting biotic responses to changing climate requires knowledge of intra- and inter-specific climate associations within the context of topographically heterogenous landscapes. Changes in temperature, snow, and rain characteristics at regional scales are amplified or attenuated by slope, aspect, and wind patterns occurring at local scales that are often under a hectare or even a meter in extent. Community assemblages are structured by the soil moisture and growing season duration at these local sites, and directional climate change has the potential to alter these two drivers together, independently, or in opposition to one another due to local, intervening variables. Changes threaten species whose water and growing season duration requirements are locally extirpated or species who may be outcompeted by nearby faster-growing, warmer/drier adapted species. However, barring non-analogue climate conditions, species may also be able to more easily track required resource regimes in topographically heterogenous landscapes. New species arrivals composed of competitors, predators and pathogens can further mediate the direct impacts of the changing climate. Plants are moving uphill, demonstrating primary succession with the emergence of new habitats from snow and rock, but these shifts are constrained over the short term by soil limitations and microbes and ultimately by the lack of colonizable terrestrial surfaces. Meanwhile, both subalpine herbaceous and woody species pose threats to more cold-adapted species. Overall, the multiple interacting direct and indirect effects of the changing climate on high elevation systems may lead to multiple potential trajectories for these systems.
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Topp SN, Pavelsky TM, Dugan HA, Yang X, Gardner J, Ross MR. Shifting Patterns of Summer Lake Color Phenology in Over 26,000 US Lakes. WATER RESOURCES RESEARCH 2021; 57:e2020WR029123. [PMID: 34219822 PMCID: PMC8244058 DOI: 10.1029/2020wr029123] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/08/2021] [Accepted: 05/06/2021] [Indexed: 06/13/2023]
Abstract
Lakes are often defined by seasonal cycles. The seasonal timing, or phenology, of many lake processes are changing in response to human activities. However, long-term records exist for few lakes, and extrapolating patterns observed in these lakes to entire landscapes is exceedingly difficult using the limited number of available in situ observations. Limited landscape-level observations mean we do not know how common shifts in lake phenology are at macroscales. Here, we use a new remote sensing data set, LimnoSat-US, to analyze U.S. summer lake color phenology between 1984 and 2020 across more than 26,000 lakes. Our results show that summer lake color seasonality can be generalized into five distinct phenology groups that follow well-known patterns of phytoplankton succession. The frequency with which lakes transition from one phenology group to another is tied to lake and landscape level characteristics. Lakes with high inflows and low variation in their seasonal surface area are generally more stable, while lakes in areas with high interannual variations in climate and catchment population density show less stability. Our results reveal previously unexamined spatiotemporal patterns in lake seasonality and demonstrate the utility of LimnoSat-US, which, with over 22 million remote sensing observations of lakes, creates novel opportunities to examine changing lake ecosystems at a national scale.
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Affiliation(s)
- Simon N. Topp
- Department of Geological SciencesUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Tamlin M. Pavelsky
- Department of Geological SciencesUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Hilary A. Dugan
- Center for LimnologyUniversity of Wisconsin‐MadisonMadisonWIUSA
| | - Xiao Yang
- Department of Geological SciencesUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - John Gardner
- Department of Geological SciencesUniversity of North Carolina at Chapel HillChapel HillNCUSA
- Department of Geology and Environmental ScienceUniversity of PittsburghPittsburghPAUSA
| | - Matthew R.V. Ross
- Department of Ecosystem Science and SustainabilityColorado State UniversityFort CollinsCOUSA
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Oleksy IA, Beck WS, Lammers RW, Steger CE, Wilson C, Christianson K, Vincent K, Johnson G, Johnson PTJ, Baron JS. The role of warm, dry summers and variation in snowpack on phytoplankton dynamics in mountain lakes. Ecology 2020; 101:e03132. [PMID: 32628277 PMCID: PMC7583380 DOI: 10.1002/ecy.3132] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/28/2020] [Accepted: 05/21/2020] [Indexed: 11/08/2022]
Abstract
Climate change is altering biogeochemical, metabolic, and ecological functions in lakes across the globe. Historically, mountain lakes in temperate regions have been unproductive because of brief ice-free seasons, a snowmelt-driven hydrograph, cold temperatures, and steep topography with low vegetation and soil cover. We tested the relative importance of winter and summer weather, watershed characteristics, and water chemistry as drivers of phytoplankton dynamics. Using boosted regression tree models for 28 mountain lakes in Colorado, we examined regional, intraseasonal, and interannual drivers of variability in chlorophyll a as a proxy for lake phytoplankton. Phytoplankton biomass was inversely related to the maximum snow water equivalent (SWE) of the previous winter, as others have found. However, even in years with average SWE, summer precipitation extremes and warming enhanced phytoplankton biomass. Peak seasonal phytoplankton biomass coincided with the warmest water temperatures and lowest nitrogen-to-phosphorus ratios. Although links between snowpack, lake temperature, nutrients, and organic-matter dynamics are increasingly recognized as critical drivers of change in high-elevation lakes, our results highlight the additional influence of summer conditions on lake productivity in response to ongoing changes in climate. Continued changes in the timing, type, and magnitude of precipitation in combination with other global-change drivers (e.g., nutrient deposition) will affect production in mountain lakes, potentially shifting these historically oligotrophic lakes toward new ecosystem states. Ultimately, a deeper understanding of these drivers and pattern at multiple scales will allow us to anticipate ecological consequences of global change better.
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Affiliation(s)
- Isabella A. Oleksy
- Natural Resource Ecology LaboratoryColorado State UniversityFort CollinsColorado80526USA
- Cary Institute of Ecosystem StudiesMillbrookNew York12545USA
| | - Whitney S. Beck
- Department of BiologyColorado State UniversityFort CollinsColorado80526USA
| | | | - Cara E. Steger
- Cary Institute of Ecosystem StudiesMillbrookNew York12545USA
| | - Codie Wilson
- Department of GeosciencesColorado State UniversityFort CollinsColorado80526USA
| | - Kyle Christianson
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsColorado80526USA
| | - Kim Vincent
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColorado80309USA
| | - Gunnar Johnson
- Department of GeologyPortland State UniversityPortlandOregon97201USA
| | - Pieter T. J. Johnson
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColorado80309USA
| | - J. S. Baron
- Natural Resource Ecology LaboratoryColorado State UniversityFort CollinsColorado80526USA
- U.S. Geological SurveyFort CollinsColorado80526USA
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Oleksy IA, Baron JS, Leavitt PR, Spaulding SA. Nutrients and warming interact to force mountain lakes into unprecedented ecological states. Proc Biol Sci 2020; 287:20200304. [PMID: 32635862 DOI: 10.1098/rspb.2020.0304] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
While deposition of reactive nitrogen (N) in the twentieth century has been strongly linked to changes in diatom assemblages in high-elevation lakes, pronounced and contemporaneous changes in other algal groups suggest additional drivers. We explored the origin and magnitude of changes in two mountain lakes from the end of the Little Ice Age at ca 1850, to ca 2010, using lake sediments. We found dramatic changes in algal community abundance and composition. While diatoms remain the most abundant photosynthetic organisms, concentrations of diatom pigments decreased while pigments representing chlorophytes increased 200-300% since ca 1950 and total algal biomass more than doubled. Some algal changes began ca 1900 but shifts in most sedimentary proxies accelerated ca 1950 commensurate with many human-caused changes to the Earth System. In addition to N deposition, aeolian dust deposition may have contributed phosphorus. Strong increases in summer air and surface water temperatures since 1983 have direct and indirect consequences for high-elevation ecosystems. Such warming could have directly enhanced nutrient use and primary production. Indirect consequences of warming include enhanced leaching of nutrients from geologic and cryosphere sources, particularly as glaciers ablate. While we infer causal mechanisms, changes in primary producer communities appear to be without historical precedent and are commensurate with the post-1950 acceleration of global change.
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Affiliation(s)
- Isabella A Oleksy
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.,Cary Institute of Ecosystem Studies, Millbrook, NY 12545, USA
| | - Jill S Baron
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO 80523, USA.,U.S. Geological Survey, Fort Collins, CO 80526, USA
| | - Peter R Leavitt
- Institute of Environmental Change and Society, University of Regina, Regina, Saskatchewan, S4S 0A2 Canada.,Institute for Global Food Security, Queen's University Belfast, Belfast, Antrim BT9 5DL, UK
| | - Sarah A Spaulding
- U.S. Geological Survey/INSTAAR, University of Colorado, Boulder, CO, USA
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