鄱阳湖湿地苔藓植物区系及分布

Flora and Distribution of Bryophytes in Poyang Lake Wetlands

采用样线法和样方法,对鄱阳湖湿地的苔藓植物和土壤进行了调查、取样。共收集鉴定鄱阳湖湿地苔藓植物16科24属31种。苔藓植物主要成分为东亚分布成分(占38.46%)和温带分布成分(占26.92%)。苔藓植物含5种生活型,按物种数量依次为矮丛集型、交织型、一年生型、高丛集型和平铺型。将鄱阳湖湿地按水位划分为高漫滩、草洲和泥滩/水域,其上分布的植物形成3条环形植物带,各种生活型的苔藓植物在其中呈现规律性的分布。土壤培养实验结果表明,土壤种质库中维管束植物和苔藓植物物种丰富度都随水位下降而呈减少趋势,尽管维管束植物的物种丰富度显著高于苔藓植物,但苔藓植物的物种丰富度并不受维管束植物的影响。鄱阳湖湿地苔藓植物的分布规律是其自身生物学特性及其与环境梯度相适应的结果。

Aninvestigation on the bryoflora and bryophytes distribution in Poyang Lake wetlands was conducted using line transect and quadrat sampling methods. A total of 31 species belonging to 16 families and 24 genera were recorded. East Asia（10 species, accounted for 38.46%） and North Temperate（7 species, accounted for 26.92%） were the major elements in bryoflora. Five categories of life forms, i.e. short turf（11 species,accounted for 35.48%）, weft（8 species, accounted for 25.81%）, annuals（8 species, accounted for 25.81%）,tall turf（3 species, accounted for 9.68%）, and mats（1 species）, were discovered in Poyang Lake wetlands.Vegetation in Poyang Lake wetlands was divided into three zones（i.e. high beach, various types of grass moors, and mud flat）, and bryophytes were regularly distributed among these zones. The species richness of bryophytes was the highest in high beach. A total of 26 species were identified from this zone, where in the main life forms were composed of short turf and weft. Nine species were found in grass moors, most of which were annual bryophytes that could adapt to seasonal water level changes. Only two species（i.e. Riccia fluitans and Ricciocarpus natans） were found in mud flat, and they were also annuals species. Soil samples in the quadrats were incubated in greenhouse for 90 days. The results showed that the species richness of both vascular plants and bryophytes tended to decrease with the water level descent. However, there was no correlation was detected between these two species richness since the correlation coefficient was only 0.047 6, but significant difference was detected by t-test with p0.0337. Although vascular plants showed competitive advantages against bryophytes in most cases, the bryophytes species richness was not affected by the vascular plants,but was more related to environmental heterogeneity. Bryophytes distribution in Poyang Lake wetlands was associated with species biological characteristicsand their adaptation to the environment gradientsof Poyang Lake.Life forms of bryophytes and seasonal variation of water level of Poyang Lake were the most two important factors determining the distribution patterns of bryophytes.