SLOW RECOVERY IN A MOUNT WASHINGTON, NEW HAMPSHIRE, ALPINE PLANT COMMUNITY FOUR YEARS AFTER DISTURBANCE

摘要

Four years after a trench was dug through alpine habitat on Mount Washington, New Hampshire, we surveyed vascular plants, bryophytes, and lichens in the disturbed area, analyzing species richness and abundance compared with values in adjacent, undisturbed areas. Plants had begun recolonizing the disturbed area, but species richness and abundance remained far lower than in the undisturbed community. Among vascular plants, graminoids colonized most quickly, and woody species were largely absent. Species with the highest frequency and greatest abundance in the disturbed area also were common and abundant in the undisturbed community. Bryophytes appeared to be colonizing no more quickly than vascular plants. Treeline and elevation exerted separate effects on community structure and recovery. Treeline influenced species richness, abundance, and the rate of recovery of vascular plants, but there was no evidence of an additional effect of elevation either above or below treeline. Treeline also influenced species richness of bryophytes and lichens. In addition, elevation appeared to have a separate effect on their rate of recovery in alpine habitat: species richness of bryophytes and lichens declined with elevation in the disturbed community but not in the undisturbed community. This suggests that elevation has a transient effect on colonization and/or survival, but only above treeline. In general, recovery has occurred more quickly below treeline. This survey establishes baseline information that will be useful in assessing the rate of recovery after future surveys