Moss distribution in streams of the Quebec Laurentian Mountains

摘要

To model the distribution of aquatic mosses, we measured their cover in 33 Quebec streams. The variation in moss cover among streams was explained mostly (42) by substratum size (percentage 25 cm in diameter). Water pH and depth also explained a significant amount of variation (9 and 10, respectively). Within a stream, moss cover was again positively correlated to the availability of large substrata and negatively to water depth. There was a strong inverse relationship between covers of moss and of the filamentous cyanobacteriumStigonema, suggesting a competitive interaction. This study confirms previous observations that moss distribution is mainly controlled by substratum size. Chemistry explains part of the among-stream variation.Stigonema-moss competition partly accounts for the patchy distribution within a stream.Key words: aquatic mosses,Fontinalis, streams, Quebec.