Swansea Village Park is home to at least four autumnal or vernal pools. This Earthcache will give you a small introduction to the science of autumnal pools as well as extra information for you to expand your pool knowledge if you are so inclined. Look at the cache location via a satellite map and you should be able to spot the pool.
In 2009, a member of local Boy Scout Troop 303 studied this vernal pool as part of his quest for Eagle Scout. He was excited to find freshly lain wood frog eggs which helped to identify this location as one of four vernal pool in Swansea's Village Park.
As you walk the trails in Village Park, you can also observe many puddingstone rock formations that are between 286 - 325 million years old, formed by glaciers. Our other Earthcache, GC3B192, gives you a brief lesson on glaciers and puddingstone rocks.
"Vernal pools are unique wildlife habitats best known for the amphibians and invertebrate animals that use them to breed. Vernal pools, also known as ephemeral pools, autumnal pools, and temporary woodland ponds, typically fill with water in the autumn or winter due to rainfall and rising groundwater and remain ponded through the spring and into summer. Vernal pools dry completely by the middle or end of summer each year, or at least every few years. Occasional drying prevents fish from establishing permanent populations, which is critical to the reproductive success of many amphibian and invertebrate species that rely on breeding habitats free of fish predators."1
"Vernal pools are small, shallow ponds characterized by a lack of fish and annual or semi-annual periods of dryness. Vernal pool habitats are extremely important to a variety of wildlife species, including some amphibians that breed exclusively in vernal pools, and other organisms such as fairy shrimp which spend their entire life cycles confined to such locales."2
"Seasonally-flooded depressions also occur throughout the Northeast. Though the name vernal pool/ pond has long been adopted, the terminology may not be totally appropriate for southern New England, as some ponds fill up with water in the late fall (actually 'autumnal' ponds). Furthermore, in the northeast, the geologic factors that determine where on the landscape seasonally-flooded pools occur is poorly understood."3
Vernal pools are geologic depressions that can form in a variety of ways. A few common origins of vernal pools are :
Floodplains - when a stream overflows its banks entering the floodplain. Some of overflow pockets retain water well and become vernal pools
Glaciers - glaciers created many isolated depressions through freezing, thawing and and erosion that fill with rain water and snowmelt
Sag Ponds - sag ponds form when surface water gathers in depressions formed by easily dissolved bedrock (such as limestone) underneath an impermeable soil layer
Human Activities - some vernal pools are created deliberately by people who wish to create wildlife habitat or to replace a seasonal wetland that was destroyed or during any kind of surface disruption (mining, roadside ditches, agricultural fields, etc. that create shallow depressions that hold water long enough to support seasonal pool wildlife) 2
A pool is also considered a Vernal pools when "hydric" soil is present. Hydric soil is soil which is permanently or seasonally saturated by water.
PLEASE MAKE ALL OBSERVATIONS FROM ABOVE, NEAR THE TRAIL, AND DO NOT GO DOWN THE SLOPE TO THE VERNAL POOL AREA. THE VERNAL POOL IS LOCATED ON PRIVATE PROPERTY.
To Log this Earthcache, please complete the following tasks:
1. Estimate the width, length and volume of the pool (volume =length x width x depth)
2. How do you think this vernal pool was created? Floodplain, glacier, sag pond or human intervention?
3. What feeds the vernal pool, i.e. what fills it seasonally? If you are visiting the vernal pool during a dry season, what indicators are there that the area may at times be a wetland?
4. (Optional) Be observant…check out the flora or fauna you see in or around the vernal pool (plants, animals, eggs, etc.) that make it a vernal pool.
5. (Optional) Take a picture of you/your team or your GPS at or near the coordinates
More information:
"BioMap2: CONSERVING THE BIODIVERSITY OF MASSACHUSETTS IN A CHANGING WORLD" - BioMap2 was developed to protect the state’s biodiversity in the context of climate change. BioMap2 identifies the top 5 percent most interconnected clusters of Potential Vernal Pools in the state (http://maps.massgis.state.ma.us/dfg/biomap/pdf/town_core/Swansea.pdf)
If you are interested in learning about the certification of Vernal Pools in Massachusetts, you can visit the Natural Heritage & Endangered Species section of the mass.gov website.
NHESP Certified Vernal Pools : http://www.mass.gov/anf/research-and-tech/it-serv-and-support/application-serv/office-of-geographic-information-massgis/datalayers/cvp.html
NHESP Potential Vernal Pools : http://www.mass.gov/anf/research-and-tech/it-serv-and-support/application-serv/office-of-geographic-information-massgis/datalayers/pvp.html
References
1. http://www.mass.gov/eea/agencies/dfg/dfw/natural-heritage/vernal-pools/
2. http://www.naturalheritage.state.pa.us/VernalPool_Geology.aspx
3. http://www.uri.edu/cels/nrs/paton/whatisavp.html