摘要 : We investigated the effects of elevation,wave exposure,and year on the proportion of gametophytes and tet-rasporophytes in populations of the intertidal red seaweed Mazzaella parksii (=M.cornucopiae,Gigartinaceae) from the Pacific... 展开 We investigated the effects of elevation,wave exposure,and year on the proportion of gametophytes and tet-rasporophytes in populations of the intertidal red seaweed Mazzaella parksii (=M.cornucopiae,Gigartinaceae) from the Pacific coast of Canada.In July 2002,we determined the life-history phase of 864 frond samples from four populations from Barkley Sound,using the resorcinol-acetal test.For these populations,gametophytes were significantly more numerous than tetrasporophytes,and the proportion of gametophytes was significantly higher at higher elevations.The proportion of gametophytes varied directly (although less markedly) with the degree of wave exposure,but significance could not be assessed for this factor.All of these patterns were spatially consistent,as they held for two different rocky points with similar physical characteristics.One of these points had also been surveyed in 1994-1995,which allows us to conclude that the population-wise gametophyte predominance and the positive relationship between elevation and the proportion of gametophytes are stable features of this species in this area.However,the average proportion of gametophytes was similar between the studied levels of wave exposure in 1994-1995;such a difference revealed as non-significant when data were combined with those for 2002.This suggests that wave exposure is not important in determining the proportion of life-history phases for this species.Comparisons with other species are done in search of general patterns for the Gigartinaceae. 收起