Earth and Atmospheric Sciences, Department of

 

Date of this Version

2020

Citation

Published in Lake and Reservoir Management 2020

doi: 10.1080/10402381.2020.1752863

Comments

Copyright © 2020 North American Lake Management Society; published by Taylor & Francis. Used by permission.

Abstract

An ecosystem’s ability to maintain structure and function following disturbance, defined as resilience, is influenced by a hierarchy of environmental controls, including climate, surface cover, and ecological relationships that shape biological community composition and productivity. This study examined lacustrine sediment records of naturally fishless lakes in Yellowstone National Park to reconstruct the response of aquatic communities to climate and trophic cascades from fish stocking. Sediment records of diatom algae did not exhibit a distinct response to fish stocking in terms of assemblage or algal productivity. Instead, 3 of 4 lakes underwent a shift to dominance by benthic diatom species from 1935 to 1950, which suggests lower lake levels resulting from warmer, drier climatic conditions. The lake that did not undergo such a shift is fed by groundwater rather than snowmelt, suggesting a buffering effect by water source. Dissimilarity analysis shows that the diatom assemblages in all 4 lakes have become increasingly dissimilar since circa 1955, suggesting that communities have not yet stabilized from the first-order influence of climate. Thus, climate likely had a more prominent influence on diatom community structure than did manipulation of the fish community. Understanding the relative importance and interplay among abiotic and biotic stressors and the resultant resilience of an ecosystem provides implications for the adaptive management of lakes.

Includes supplemental materials

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