Body size distributions signal a regime shift in a lake ecosystem

Proceedings of the Royal Society B
By: , and 

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Abstract

Communities of organisms, from mammals to microorganisms, have discontinuous distributions of body size. This pattern of size structuring is a conservative trait of community organization and is a product of processes that occur at multiple spatial and temporal scales. In this study, we assessed whether body size patterns serve as an indicator of a threshold between alternative regimes. Over the past 7000 years, the biological communities of Foy Lake (Montana, USA) have undergone a major regime shift owing to climate change. We used a palaeoecological record of diatom communities to estimate diatom sizes, and then analysed the discontinuous distribution of organism sizes over time. We used Bayesian classification and regression tree models to determine that all time intervals exhibited aggregations of sizes separated by gaps in the distribution and found a significant change in diatom body size distributions approximately 150 years before the identified ecosystem regime shift. We suggest that discontinuity analysis is a useful addition to the suite of tools for the detection of early warning signals of regime shifts.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Body size distributions signal a regime shift in a lake ecosystem
Series title Proceedings of the Royal Society B
DOI 10.1098/rspb.2016.0249
Volume 283
Issue 1833
Year Published 2016
Language English
Contributing office(s) Coop Res Unit Seattle, John Wesley Powell Center for Analysis and Synthesis
Description Article 20160249