Within each watershed, all water runs to the lowest point - a stream or lake. On its way, water travels over the surface and across farm fields, forest land, suburban lawns and city streets, or it seeps into the soil and travels as ground water. There are 27 watersheds in Massachusetts. A living community of plants, animals, and microorganisms. Examples of a natural community include vernal pools, red maple swamps, saltmarshes, and sandplain grasslands.
Watersheds are ecosystems.
They contain smaller ecosystems, called natural communities, and are nested within larger ecosystems, called ecoregions. Ecoregion - Landscape units within which environmental conditions are similar. Massachusetts has 13 ecoregions in two zones, the Northeastern Coastal Zone and the Northeastern Highlands Zone.