Shifts in patterns of microhabitat occupation by six closely related species of mosses along a complex altitudinal gradient.

Changes in patterns of microhabitat occupation were examined for six closely related moss species (family Polytrichaceae) found growing together along a complex altitudinal gradient on the northeast face of Mount Washington, New Hampshire. Little evidence could be found to support the hypothesis that the relative distributions of these six moss species were determined by competitive interactions occurring among them. Instead, the data support the hypothesis that changing patterns in the relative distributions of these six moss species result from differences in microhabitat availability among sites. The moss species appear to behave in an opportunistic manner, occupying a wide array of microhabitats as these microhabitats become available to them.