PARENT SESSION
Oral Session 23: Biodiversity II: Theory; Modeling.
Presiding: M Koechy
Tuesday, August 3, 8:00 AM to 11:30 AM, Meeting Room B 113.
The relationship between soil mite species richness and decomposition in a tallgrass prairie: A contest among models.
St. John, Mark1, Wall, Diana1, Reed, Heather2, 1 Natural Resource Ecology Laboratory, Fort Collins, CO, USA2 Institute for Arctic and Alpine Research and Department of EEB, Boulder, CO, USA
ABSTRACT- Most investigations of the relationship between biodiversity and ecosystem function (BEF) are either laboratory or highly manipulated field studies, making applicability to natural conditions difficult. Furthermore, these studies are usually biased to aboveground species and processes, which may not be relevant to belowground systems. We measured rates of cotton strip decomposition at sites with low and high fire frequencies, which differed in soil mite diversity, on the Konza Prairie Biological Station in Kansas. Using likelihood-based approaches, we examined strength of evidence in cotton decomposition data for models representing the Null, Rivet and Redundant patterns of BEF. The model representing redundancy in the total abundance of mites, NTotal, had more support in the data than any of the other competing models (Akaike weight, wr = 0.44). The model representing a high degree of redundancy in the species richness of Mesostigmata, SMeso was also well supported (wr = 0.24). Models representing the Rivet patterns were soundly rejected when compared to data (wr < 0.01). Null models, those with no biotic effects, were also rejected in competition with Redundant models. Maximum-likelihood estimates of model parameters closely matched empirical measurements, supporting the mechanisms represented by the models. Models predicted data from high fire frequency sites best, consistent with expectations that sites with low fire frequency would have greater biophysical legacies buffering against effects of dominant process drivers.
Key words: Biophysical Legacy, Decomposition, Biodiversity, Mite