祁连山林区苔藓垂直分布特征与水文功能分析

Vertical Distribution Characteristics and Hydrological Function Analysis of Bryophytes in Qilian Mountains Forest Areas

苔藓是祁连山林区地被层植物的主要建群种,具有保持林区环境湿润、调节地表径流和涵养水源的功能。通过野外调查,结合苔藓植物的分布情况和环境特征,将研究区苔藓植物垂直分布划分为低山苔藓植物带、乔木林苔藓分布带、亚高山灌丛林苔藓分布带,对各带的主要苔藓种类和分布情况做了较详细的描述。由于各带苔藓厚度有明显的不同,导致含水量有明显的差异。当苔藓最大厚度达到7.4 cm时,苔藓的最大持水率为519.44%,随厚度降低持水率变小。林区苔藓在5月含水量最大,7月最小,从5月到9月含水量呈递减趋势;并对林内无苔藓覆盖和林内有苔藓覆盖的土壤水分蒸发做了比较分析,得到这两者蒸发大小的顺序是:林内无苔藓覆盖>林内有苔藓覆盖。

Bryophytes are the main understory dominant species in forest areas of Qilian Mountain, which play an important role in keeping a humid environment, surface runoff modulation and water sources holding. We conducted a field investigation of bryophytes along altitude gradient, and made a detailed bryophytes taxonomy. Based on the characteristics of bryophytes distribution, partitioning them into different distribution zones, including low altitude bryophytes distribution zones, arboreal bryophytes distribution zones and alpine bryophytes distribution zones. The water-holding capacity of bryophytes varied with its layers＇ thickness, and reached the maximum 519.44% when the layers is 7.4 cm thick, in the forest areas, bryophytes water content showed a downtrend from May to September, with maximum occurred in May and minimum in July, moreover, soil with bryophytes coverage showed lower evaporation than that without bryophytes coverage