Does temporal resource variability influence biodiversity? A test with protist communities from the pitcher plant Sarracenia purpurea

Background/Question/Methods

Most ecosystems have permeable boundaries and are influenced by the movement of resources between surrounding environments. Such resource movements can have profound impacts on the structure and function of recipient communities. Numerous studies have examined how resource dynamics can influence population sizes and have compared the nutritional quality of local and subsidized food resources. In recent years, there has been increasing focus on understanding the consequences of rare, extreme resource pulses that dramatically increase short-term resource availability in recipient communities. Despite a breadth of research on how resources impact consumers, consequences of temporal resource variability remain largely understudied.

Results/Conclusions

We examined how temporal variability in resource supply impacts protist communities from pitchers of the purple pitcher plant Sarracenia purpurea. An 82-day microcosm experiment manipulated the frequency of resource additions to protist communities. The high frequency treatment supported greater rarified taxonomic richness than the low frequency and controls. Treatments also led to differences in functional community composition, with low frequency communities dominated by highly mobile ciliates and high frequency communities dominated by comparatively sessile amoebae. Our results build on the growing body of literature examining the ecological consequences of pulsed resources. By manipulating pulse frequency, this work furthers our fundamental understanding of the relationships between temporal resource variability and biodiversity.