- The study examined how competitive interactions with salamander larvae and abiotic habitat variables determine macroinvertebrate species richness in ephemeral ponds. - Experimental sites varied in canopy cover (open or closed) and presence/absence of salamander larvae. Species richness was highest in open sites and was best predicted by abiotic habitat variables like hydroperiod rather than biotic interactions. - Competition from salamander larvae appeared to have little impact on species richness, possibly due to the highly disturbed nature of ephemeral ponds and low larval densities.

1. Macroinvertebrate Communities in Ephemeral Ponds: Effects of Competition, Landscape, and Hydroperiod on Species Richness Edmund Hart University of Vermont ESA 2007

3. Ponds Undergo Regular Drying

4. Common Ephemeral Pond Taxa

6. Schematic of community structure. .2 .4 .9 .6 .7 .1 .3 .2 .5 Hydroperiod .8 .3 .3 .1 .1 .5 .2 .1 .8 .9 .4 .6 .2 = Taxa that can utilize ephemeral habitat = Taxa already present In habitat = Potential colonizer Model drawn after Schnieder and Frost (1996)

7. Study question Do competitive interactions with salamander larva Or abiotic habitat variables determine invertebrate species richness?

12. Since design was not fully crossed, a saturating likelihood results when too many factors are added into the model. Therefore interaction terms could not be considered, only additive effects of two parameters. Candidate Models

13. Results Species Richness by Treatment

14. Results Individual based rarefaction curves generated by EstimateS (Colwell 2005). Open sites have higher species diversity.

15. The model with habitat and hydroperiod predictors best fits the data, also having the highest AICc weight and bootstrap frequency. Model Results

17. Questions? Worms sure are tastier than bugs Thanks DEWA staff, Rich Evans, USGS BRD Brian Beckage, Nick Gotelli