杭州市区土生苔藓植物分布与生态因子的关系

在杭州市区设立的21个样点中,记录到土生苔藓植物22科31属47种.基于样点中苔藓植物种类的生态重要值和样点生态因子数据进行典范对应分析.结果表明:人为干扰和土壤pH是影响杭州市区土生苔藓植物分布的主要生态因子.在市区平原地势的公园和绿地,人为干扰较大,土壤呈碱性,苔藓植物种类以小羽藓属、真藓属和丛藓科为主;而在海拔较高的丘陵地区,人为干扰较小,土壤呈酸性,苔藓植物种类相对丰富,侧蒴藓类和苔类较多.对47种土生苔藓植物进行生态位宽度计测,多数苔藓植物的生态位宽度较窄.其中,东亚拟鳞叶藓的生态位宽度最大(0.3510),广泛分布在西湖西南的丘陵地区;平叶毛口藓和细叶小羽藓的生态位宽度次之,分别为0.2239和0.2185,是市区平原地势的公园和绿地中的常见种.

Relationships between distribution of soil-born bryophytes in urban area of Hangzhou and related ecological factors.

At the 21 sampling sites in urban area of Hangzhou, 47 species of soil-born bryophytes belonging to 31 genera and 22 families were recorded. Based on the ecological importance value of these species and the data of ecological factors at the sampling sites, the relationships between the distribution of the bryophytes species in urban area of Hangzhou and related ecological factors were studied by canonical correspondence analysis. The results showed that human disturbance and soil pH were the most important factors determining the distribution of the bryophytes. In urban parks and green lands where human disturbance was greater, soil pH was alkali, and the species were mainly belonging to the genera of Haplocladium and Bryum and the family of Pottiaceae. In hilly area where human disturbance was lesser, soil pH turned to acidic, and the bryophytes were more, with pleurocarpous mosses and liverworts being relatively rich. The niche width of the 47 bryophytes was calculated, which revealed that most of them had very narrow niche width (<0.1). The Pseudotaxiphyllum pohliaecarpum widely distributed in the hilly area of southwest Xihu Lake had the widest niche width (0.3510), followed by Trichostomum planifolium (0.2239) and Haplocladium microphyllum (0.2185), the commonest species in the parks and greenlands in urban area of Hangzhou.