TY - JOUR
T1 - Spatial and Temporal Ecological Uniqueness of Andean Diatom Communities Are Correlated With Climate, Geodiversity and Long-Term Limnological Change
AU - Benito, Xavier
AU - Vilmi, Annika
AU - Luethje, Melina
AU - Carrevedo, Maria Laura
AU - Lindholm, Marja
AU - Fritz, Sherilyn C.
N1 - Funding Information:
We thank D. R. Engstrom, Science Museum of Minnesota, for analysis and interpretation of the 210Pb profiles from the study lakes. We are enormously indebted to all the contributors of the South American diatom database (https://github.com/xbenitogranell/diatoms-biogeography-southamerica), including M. I. Velez, P. Tapia, M. Steinitz-Kannan, B. Valencia, M. Bush, F. Mayle, and J. P. Bradbury. We are greatly thankful to Paul A. Baker, Kewrin Choez, and Maria Arteaga for fieldwork assistance in Imbabura Province, Pablo Mosquera and Henni Hampel for help with Cajas National Park lakes limnology, and ETAPA EP rangers and Simon Quiroz for assistance during fieldwork. We also thank the Ministerio del Ambiente in Ecuador for permitting to conduct this research (151-2017-DPAA/MA and 008-IC-DPACH-MAE-2017). Funding. XB was supported by the National Socio-Environmental Synthesis Center (SESYNC), under funding received from the US NSF DBI-1639145. MLu and SF acknowledge funding from National Geographic #8672-09 and NSF EAR-1338694. MC was supported by a FONDECYT postdoctoral fellowship. AV was supported by the project FRESHABIT LIFE IP (LIFE14/IPE/FI/023).
Publisher Copyright:
© Copyright © 2020 Benito, Vilmi, Luethje, Carrevedo, Lindholm and Fritz.
PY - 2020/9/2
Y1 - 2020/9/2
N2 - High-elevation tropical lakes are excellent sentinels of global change impacts, such as climate warming, land-use change, and atmospheric deposition. These effects are often correlated with temporal and spatial beta diversity patterns, with some local communities contributing more than others, a phenomenon known as local contribution to beta diversity (LCBD) or ecological uniqueness. Microorganisms, such as diatoms, are considered whole-ecosystem indicators, but little is known about their sensitivity and specificity in beta diversity studies mostly because of the lack of large spatial and temporal datasets. To fill this gap, we used a tropical South American diatom database comprising modern (144 lakes) and paleolimnological (6 sediment cores) observations to quantify drivers of spatial and temporal beta diversity and evaluated implications for environmental change and regional biodiversity. We used methods of beta diversity partitioning (replacement and richness components) by determining contributions of local sites to these components (LCBDrepl and LCBDrich), and studied how they are related to environmental, geological, and historical human variables using Generalized Additive Models (GAM). Beta replacement time series were also analyzed with GAM to test whether there is widespread biotic homogenization across the tropical Andes. Modern lake ecological uniqueness was jointly explained by limnological (pH), climatic (mean annual precipitation), and historical human density. Local lake (conductivity) and regional geodiversity variables (terrain ruggedness, soil variability) were inversely correlated to replacement and richness components of LCBD, suggesting that not all lakes contributing to broad-scale diversity are targets for conservation actions. Over millennial time scales, decomposing temporal trends of beta diversity components showed different trajectories of lake diatom diversity as response of environmental change: i) increased hydroclimatic variability (as inferred by decreased temperature seasonality) mediating higher contribution of richness to local beta diversity patterns ca. 1000 years ago in Ecuador Andean lakes and ii) lake-specific temporal beta diversity trends for the last ca. 200 years, indicating that biotic homogenization is not widespread across the tropical Andes. Our approach for unifying diatom ecology, metacommunity, and paleolimnology can facilitate the understanding of future responses of tropical Andean lakes to global change impacts.
AB - High-elevation tropical lakes are excellent sentinels of global change impacts, such as climate warming, land-use change, and atmospheric deposition. These effects are often correlated with temporal and spatial beta diversity patterns, with some local communities contributing more than others, a phenomenon known as local contribution to beta diversity (LCBD) or ecological uniqueness. Microorganisms, such as diatoms, are considered whole-ecosystem indicators, but little is known about their sensitivity and specificity in beta diversity studies mostly because of the lack of large spatial and temporal datasets. To fill this gap, we used a tropical South American diatom database comprising modern (144 lakes) and paleolimnological (6 sediment cores) observations to quantify drivers of spatial and temporal beta diversity and evaluated implications for environmental change and regional biodiversity. We used methods of beta diversity partitioning (replacement and richness components) by determining contributions of local sites to these components (LCBDrepl and LCBDrich), and studied how they are related to environmental, geological, and historical human variables using Generalized Additive Models (GAM). Beta replacement time series were also analyzed with GAM to test whether there is widespread biotic homogenization across the tropical Andes. Modern lake ecological uniqueness was jointly explained by limnological (pH), climatic (mean annual precipitation), and historical human density. Local lake (conductivity) and regional geodiversity variables (terrain ruggedness, soil variability) were inversely correlated to replacement and richness components of LCBD, suggesting that not all lakes contributing to broad-scale diversity are targets for conservation actions. Over millennial time scales, decomposing temporal trends of beta diversity components showed different trajectories of lake diatom diversity as response of environmental change: i) increased hydroclimatic variability (as inferred by decreased temperature seasonality) mediating higher contribution of richness to local beta diversity patterns ca. 1000 years ago in Ecuador Andean lakes and ii) lake-specific temporal beta diversity trends for the last ca. 200 years, indicating that biotic homogenization is not widespread across the tropical Andes. Our approach for unifying diatom ecology, metacommunity, and paleolimnology can facilitate the understanding of future responses of tropical Andean lakes to global change impacts.
KW - GAM
KW - beta diversity components
KW - biotic homogenization
KW - diatoms
KW - metacommunity
UR - http://www.scopus.com/inward/record.url?scp=85091031307&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85091031307&partnerID=8YFLogxK
U2 - 10.3389/fevo.2020.00260
DO - 10.3389/fevo.2020.00260
M3 - Article
AN - SCOPUS:85091031307
VL - 8
JO - Frontiers in Ecology and Evolution
JF - Frontiers in Ecology and Evolution
SN - 2296-701X
M1 - 260
ER -