RT Journal Article
SR Electronic
T1 The relationship between species richness and ecosystem variability is shaped by the mechanism of coexistence
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 098384
DO 10.1101/098384
A1 Andrew T. Tredennick
A1 Peter B. Adler
A1 Frederick R. Adler
YR 2017
UL http://biorxiv.org/content/early/2017/01/04/098384.abstract
AB Theory relating species richness to ecosystem variability typically ignores the potential for environmental variability to promote species coexistence. Failure to account for fluctuation-dependent coexistence mechanisms may explain observed deviations from the expected negative diversity-variability relationship, and limits our ability to predict the consequences of future increases in environmental variability. We use a consumer-resource model to explore how coexistence via the temporal storage effect and relative nonlinearity affects ecosystem variability. We show that a positive, rather than negative, diversity-variability relationship is possible when ecosystem function is sampled across a natural gradient in environmental variability and diversity. We also show how fluctuation-dependent coexistence can buffer ecosystem functioning against increasing environmental variability by promoting species richness and portfolio effects. Our work provides a general explanation for variation in observed diversity-variability relationships and highlights the importance of conserving regional species pools to help buffer ecosystems against predicted increases in environmental variability.