Skip to main content
U.S. flag

An official website of the United States government

Temporal gamma-diversity meets spatial alpha-diversity in dynamically varying ecosystems

January 1, 2019

Community measures collected at a single instance or over a short temporal period rarely provide a complete accounting of biological diversity. The gap between such “snapshot” measures of diversity and actual diversity can be especially large in systems that undergo great temporal variation in environmental conditions. To adequately quantify diversity in these temporally varying ecosystems, individual measures of diversity collected throughout the range of environmental variation, i.e., temporal alpha-diversity measures, must be combined to obtain temporal gamma-diversity. Such a time-integrated gamma-diversity measure will be a much closer approximation of a site’s true alpha-diversity and provide a measure better comparable to spatial alpha-diversity measures of sites with lower temporal variation for which a single or a few “snapshot” measures may suffice. We used aquatic-macroinvertebrate community-composition data collected over a 24-year period from a complex of 16 prairie-pothole wetlands to explore the rate that taxa accumulate over time at sites with differing degrees of temporal variation. Our results show that the rate of taxa accumulation over time, i.e., the slope of the species–time relationship, is steeper for wetlands with ponds that frequently dry compared to those with more-permanent ponds. Additionally, we found that a logarithmic function better fit species accumulation data for seasonally ponded wetlands whereas a power function better fit accumulations for permanently and semi-permanently ponded wetlands. Thus, interpretations of ecological diversity measures, and conservation decisions that rely on these interpretations, can be biased if temporal variations in community composition are not adequately represented.

Publication Year 2019
Title Temporal gamma-diversity meets spatial alpha-diversity in dynamically varying ecosystems
DOI 10.1007/s10531-019-01756-1
Authors David M. Mushet, Matthew J. Solensky, Shay F. Erickson
Publication Type Article
Publication Subtype Journal Article
Series Title Biodiversity and Conservation
Index ID 70217671
Record Source USGS Publications Warehouse
USGS Organization Northern Prairie Wildlife Research Center