Abstract Detail


Reed, William J [1], Oldfather, Meagan [2], Emery, Nancy [3].

Alpine tundra community and population responses to environmental predictability and variability.

One of the most reliable features of natural systems is that they fluctuate in time. Evolutionary theory predicts that the magnitude (variability) and the predictability of changes through time can favor different adaptive strategies for when and how species respond to environmental change. As climate becomes more variable and unpredictable, species strategies may become mismatched with the patterns of environmental variability they encounter. In this study, we examined the responses of alpine tundra plant communities to changes in average environmental conditions and the variability and predictability of these conditions. We used five years of annual vegetation surveys collected from permanent plots at the Niwot Ridge LTER site, located above tree line in the Front Range of the Southern Rocky Mountains. Vegetation plots are co-located with environmental sensors that collect high-resolution soil moisture and temperature data, providing a unique opportunity to evaluate how fine-scale temporal environmental variability influences plant community and population dynamics. We used multivariate ordination methods to evaluate how spatial and temporal patterns of variability in moisture and temperature influence changes in plant community composition and generalized linear models to describe species associations with different degrees of temporal variability and predictability patterns both within and across growing seasons. We documented changes in community composition in response to temporal variation in soil moisture and temperature across the relatively short period of this study, but the magnitude, direction, and environmental drivers of these changes varied among plots. We also quantified the extent to which species abundances were predicted by the mean, variability, or predictability of different environmental variables, which allowed us to characterize species strategies for responding to fluctuating conditions. Our results demonstrate the role of temporal environmental variation (i.e., variability and predictability of soil moisture and temperature) in driving patterns of community composition and species abundances within the alpine tundra. These findings are particularly relevant as scientists strive to predict the impacts of increasing climate variability on alpine plant species and communities.

1 - University of Colorado, Boulder, CO, 80309, United States
2 - 760 Grape Ave, Boulder, CO, 80304, United States
3 - University Of Colorado Boulder, Ecology And Evolutionary Biology, 2495 Juniper Ave., University Of Colorado Boulder, Boulder, CO, 80304, United States

none specified

Presentation Type: Oral Paper
Number: EC05004
Abstract ID:834
Candidate for Awards:None

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