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Restoring amphibian diversity in manufactured ponds: If you drain it, they will come.
Fauth, John*,1, 1 College/University of Charleston, Charleston, South Carolina
ABSTRACT- Ecological theory predicts ponds with intermediate hydroperiods will maintain the greatest diversity of amphibians, and of other species with complex life cycles. I tested this hypothesis by experimentally draining two types of permanent, manufactured ponds: wildlife ponds and borrow pits. Wildlife ponds were intentionally created as wildlife watering holes, while borrow pits are aquatic habitats created when construction crews remove fill for roads. The experiment had a 2 x 2 x 2 x 3 design, where treatments were the two pond types, which were drained either in summer alone, in winter alone, in both summer and winter, or never. Each of these eight treatments was replicated three times within the Francis Marion National Forest, South Carolina. Twelve nearby natural, temporary ponds were sampled for amphibians at the same time, to assay natural patterns of variation in species richness and abundance. Pond-draining had tremendous effects on amphibian species richness, which varied significantly with pond type. Species richness in borrow pits doubled, and increased 50% in wildlife ponds that were drained, compared to those left full. Summer draining increased species richness more than draining in winter. In addition, amphibian abundance increased several orders of magnitude in ponds that were drained, compared to those left full. The results indicate pond-draining, which is another application of the intermediate disturbance hypothesis, can rapidly restore amphibian diversity in manufactured wetlands.
KEY WORDS: amphibians, disturbance, diversity, hydroperiod