Manassas National Battlefield Park hosts a variety of wetlands and seeps. Among the most interesting are vernal pools. Vernal pools are shallow depressions that retain water only during certain times of the year. These small, isolated wetlands usually fill with water in the spring when snow melts and rainfall accumulates before being soaked up by thirsty tree roots or draining into the Chesapeake Bay Watershed. The time it takes the vernal pool to dry out depends on the depth of the depression, soil permeability, and inches of rainfall. Due to the fact that vernal pools are only temporary, they cannot support fish. Vernal pools make a wonderful breeding ground for amphibians, which can mate and lay eggs with little or no fear of predators. Because of this, nearly fifty percent of amphibians in North America breed primarily in vernal pools. The spotted salamander, Ambystoma maculatum, is an excellent example of an interesting creature that could not survive in Northern Virginia without vernal pools to breed in. An egg mass containing roughly two hundred eggs is laid on plant debris in the vernal pool's waters in early spring. Shortly after, the eggs hatch into larvae that grow and develop in the vernal pool while feeding on zooplankton and insect larvae. When they reach maturation, the spotted salamanders live a covert lifestyle, eating insects and remaining hidden in moist places underground or nestled under wet logs and rocks. Vernal pools may look like just a puddle to some; however, upon further inspection, one would find that they are an important habitat that is crucial to the delicate life cycle of frogs, salamanders, turtles and other creatures. Manassas National Battlefield is an important natural resource refuge that is an asset to the public and the environment. The Stone Bridge loop trail's boardwalk ascends over a vernal pool, providing a great viewing opportunity for visitors.
Did You Know?
Confederate troops destroyed the Stone Bridge over Bull Run in March 1862 before falling back to a more defensible position fifty miles to the south near Fredericksburg. The current structure was completed in the 1880s, on the site of the war-time bridge.