Jon Atwood, PhD
Department of Environmental Studies
Vernal pools are often defined in New England on the basis of certain indicator species of plants and animals. This project examines the eco-occurrenceof several common indicator species and the biotic and abiotic characteristics associated with their presence or absence. During late winter to late spring 1999 I examined 29 bodies of water located on property of the Beaver Brook Association in Hollis, New Hampshire and determined presence or absence of spotted salamanders (Ambystoma maculatum), Jefferson/blue-spotted salamanders (Ambystoma jeffersonianum and A. laterale complex), wood frogs (Rana sylvatica), and fairy shrimp (order Anostraca). In 21 of 29 pools Ambystomid salamanders and fairy shrimp were both present and in 12 pools all three vernal pool indicator species were found. Logistic regression results indicated that probability of pool occupancy by the indicator species declined with increasing pool size (perimeter) and increasing pool depth. The three indicator species were found in pools with pH values ranging from 2.5-6.7. There was no evidence that canopy cover or site type (isolated pool vs. wetland complex) affects the presence or absence of indicator species.