The Forest Bird Survey of Southern New England, the eight year long project of Bird Conservation Research, Inc. to map density distribution of the region's forest birds, also conducted habitat surveys along its 2220 census points. The survey examined field conditions in 3417 ha of forest, a sample nearly 100 times that of periodic U.S. Forest Service surveys in Connecticut and Rhode Island.
Like the Forest Service surveys, BCR studies evaluated proportionate cover of major forest types. In addition, BCR examined forest canopy cover, prevailing tree diameter, understory density, moisture regime, and elevation. The data are to be used to seek relationships between habitat distributions and distributions of forest bird densities.
Analysis of cover types shows that the forests of Rhode Island (RI in the graph below) are dominated by xeric oak and conifer associations. Northeast Connecticut (NECT) most resembles Rhode Island in its forest composition; both these regions are extensively underlain by glacial sand and gravel. The locations most heavily dominated by oak forests are Southeast (SECT) and Southwest (SWCT) Connecticut, where lower elevations and milder climates prevail. Central Connecticut (CECT) also has a high proportion of oak forests, but has as well extensive cover by more mesic-associated mixed deciduous forests. Much of the remaining forest in heavily urbanized central Connecticut is indeed in wetter environments. Northwest Connecticut (NWCT), with the most mountainous terrain in southern New England, has less cover by oaks and more cover by conifer-hardwood forests. Such forests are generally associated with cooler, northern climates.