Author

Ryan G. Smith

Date of Award

5-2014

Document Type

Thesis

Department

Environmental Science

Thesis Advisor

Kimberly Schulz

Abstract

Small permanent to semi-permanent wetland pools were at one point very abundant in northern temperate regions. Due to habitat degradation there has been a drastic decrease in their numbers. Construction of vernal pools is becoming more common to replace lost pools and help conserve these specialized habitats for abundant and endangered amphibian species. There is little study of factors regulating ecosystem processes in pools, even though factors regulating autochthonous production or respiration levels may affect amphibian success. A subset of 26 (72 total) constructed vernal pools in a mixed second growth forest (Heiberg Forest, Tully, NY) were measured for primary productivity (GPP, NPP) and respiration. It was hypothesized that conditions which reduced light in the water column would be negatively correlated with autochtonous production as estimated by both algal biomass and primary production in the water column, and that higher respiration would be correlated with higher DOC concentrations which should promote heterotrophic bacterial growth. Surprisingly although canopy cover was relatively high and uniform (82 + 4.2% SD), chlorophyll a was relatively high, similar to levels in mesotrophic lakes, and average GPP for all pools was positive, although variable (1.2 + 5.2 mg C m-3 day -1). Average net primary productivity in the pools was negative, although 7 of the 26 pools had positive NPP, suggesting net autotrophy for some of the pools in summer. No simple correlations between NPP or algal biomass and any other measured parameter were significant. Similarly, higher respiration rates in pools were not correlated with DOC concentrations, perhaps because DOC was surprisingly low. Ongoing work in collaboration with other scientists is evaluating additional factors and multivariate models that may help explain differences in autochthonous production and respiration among these constructed vernal pools. Pools with net autochthony and allochthony will also be examined for differences in amphibian breeding success measured by other collaborating scientists.

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