Spore Dispersal Distances in Atrichum angustatum (Polytrichaceae)

Abstract

Spores released from two colonies of Atrichum angustatum (Brid.) Bruch & Schimp. in B.S.G. in North Carolina were sampled within a 15-m radius of each colony to determine the scale and pattern of dispersal. The density of recovered spores decreased inversely with increasing height and distance from the center of each colony. Of the counted spores, 94% fell within 2 m of the colony centers, and only 1% of the recovered spores were collected from the 15-m perimeter of the study areas. Nevertheless, when the increased volume of air associated with greater sampling distance was considered, 4.5 million and 2.4 million spores were estimated to have reached the limits of the study areas of colonies I and II, respectively. The total number of spores dispersed was estimated to be 69 million for colony I and 25.8 million for colony II. It is clear from our data that spore dispersalfrom an established population of mosses in a wooded area is not necessarily restricted to its immediate perimeter.