Peeps and quacks of breeding amphibians are beginning to permeate our woodlands. Follow them and you will find a vernal pool, pond, or stream in healthy spring form. Steep Rock Association has put forth much effort investigating the amphibian community utilizing these aquatic habitats. For those who missed it, below is an article from the VISTA Summer 2015 Newsletter summarizing the pilot year of our vernal pool monitoring. Stay tuned for updates and photographs as we carefully muck through these unique environments in the coming month.
Vernal pools have been designated as a type of critical habitat throughout Steep Rock properties…and for good reason. These isolated, woodland water bodies fill seasonally, reaching maximum volume in the spring, and then dry-up annually or every few years. Due to the absence of fish predation, amphibian and invertebrate species have been able to adapt to the hydrologic regime and take advantage of this unique, temporary environment. Some animals, known as obligate species, are completely dependent on vernal pools for reproduction and life stage development. Here in Connecticut, obligate species include the fairy shrimp, wood frog, and four species of mole salamander (spotted, blue-spotted, jefferson’s, and marbled).
As ecologically-minded stewards of our land, we are interested in monitoring these habitats to document any temporal changes in condition and occupancy, which allows us to ensure their continued existence and importance to woodland communities. Detailed surveys of all vernal pools on Steep Rock preserves have been completed, constituting baseline data on pool characteristics, vegetative structure, and biological inventory.
Pools exhibited a considerable degree of variance in size, depth, in-basin vegetation, woody debris, and canopy closure. However, almost all were found in mature, mixed hardwood and hemlock stands, with floors composed of leaf litter. The array of life observed was remarkable. Isopods (a small crustacean), aquatic beetles and worms, snails, and a slew of fly larvae were frequently seen crawling or darting about. Green frogs and peepers ducked for cover while gray treefrogs called from the safety of nearby trees. Wood ducks secretively swam amongst woody vegetation and veeries hopped between sphagnum-covered rootwads in the more substantial pools. Although not many mammals were encountered, signs of their presence were bountiful in the form of scat, tracks and fur. Our observations also confirmed the presence of obligate species. Fairy shrimp were seen in 3 adjacent pools. Wood frog egg masses and/or tadpoles were detected in all but one of the 24 sites surveyed. Spotted salamanders were the most abundant of the obligate salamander species, present in 83% of pools, followed by jefferson’s (17%), marbled (8%), and blue-spotted salamanders (4%).
It is apparent that vernal pools play a critical role in Steep Rock woodlands and contribute enormously to biodiversity. Monitoring efforts will continue annually to help us better understand their traits, assess the value of their availability, and guide our land management practices.
