Natural Communities of NH -- Photo Guide

Vernal woodland pool


NOTE: This community has been deleted. Vernal pools are considered important ecological features, but not distinct natural community types.

Vernal pools are small, isolated depressions that are generally flooded only seasonally and often dry out completely during the course of the growing season. Water levels are controlled by precipitation and groundwater fluctuations. The cycle of wet and dry phases prevents the establishment of fish populations. With these predators excluded, vernal pools are safe harbors for numerous animal species, and serve as important feeding and breeding grounds for reptiles, amphibians, and invertebrates, several of which are adapted to and completely dependent upon the cyclic and ephemeral nature of these wetland basins.

Vernal pools typically are not large enough to break the forest canopy above. They range from unvegetated to sparsely or sometimes moderately vegetated. They are defined biologically by characteristic animal species, not vegetation. Plant species richness and cover are highly variable and typically low. Vegetation is often restricted to elevated mounds or areas near the pool margins.

Two natural community types are described. Vernal woodland pools occur in upland forest settings.

Vernal pool at Manchester Cedar Swamp Preserve (photo by Ben Kimball for the NH Natural Heritage Bureau)

A full vernal woodland pool at Pawtuckaway State Park (photo by Ben Kimball for the NH Natural Heritage Bureau)

Wood frogs are one of several amphibian species that breed in vernal pools (photo by Ben Kimball for the NH Natural Heritage Bureau)

An irregularly-shaped vernal woodland pool at Chase Bird Sanctuary in Hopkinton (photo by Ben Kimball for the NH Natural Heritage Bureau)

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