Demographic study of the macrothallus of Leathesia difformis (Phaeophyta) in Nova Scotia

Abstract

A population of Leathesia difformis macrothalli was examined by actuarial analysis. Plants were present for only 12 weeks between mid-June and early September. During that time, increasing mortality rate was correlated with increased crowding. Experimental reduction of crowding markedly reduced mortality rates. Mortality rate was also correlated with wave motion. Leathesia difformis grew epiphytically on Chondrus crispus and Corallina officinalis. Mortality rates were not significantly affected by host species type. Harvesting of biomass increments and knowledge of mortality rates allowed estimation of net production by the L. difformis population as 17 mg C∙m−2∙day−1.