Floristic relationships and dynamics of hemlock ( Tsuga canadensis) communities in Rhode Island.

Cluster analysis of 9 hemlock stands in Rhode Island and eastern Connecticut resulted in 2 groups: a hemlock-white pine Pinus strobus group and a hemlock-hardwoods group consisting of two sub-groups, hemlock-chestnut oak Quercus prinus and hemlock-mixed hardwoods. Hemlock is the most abundant species in the overstory and dominates regeneration in all stands. Age distribution of hemlock in all but one stand approaches an uneven-aged condition. Seven of the stands show evidence of disturbance including logging, windfall and possibly fire. Hemlock is the only species showing both growth releases and suppressions indicating great flexibility to respond to environment events. The characteristically contagious arrangement of understory hemlock is attributed to sporadic reproduction in favorable locations, while the random distribution of overstory hemlock stems is related to tolerance to competition and ability to fill canopy openings. -from Author