洞庭湖湿地植物生活型与生态型

Life forms and ecotypes of wetland plants at Lake Dongting wetlands

研究植物生活型和生态型可以深刻解析植物群落结构和其环境的关系,对研究植物群落的发生、发展以及演替规律都具有重要意义.通过对洞庭湖湿地植物群落物种生活型及生态型进行调查研究,结果表明:洞庭湖湿地植物主要生长型为草本植物,其次为藤本植物,木本类植物缺乏;生活型主要为一年生植物,其次为地下芽和地面芽植物,高位芽和地上芽植物最少.在不同典型群落中,高位芽和地上芽植物在不同群落中所占比重随着高程的递增而增加,且相同生活型在不同群落中所占的比重也随高程的递增而增加.植物生态型构成中,水分生态型以湿生植物为主,土壤pH值生态型以中性土植物最多,光照强度生态型以阳性植物为主,淤积生态型以非淤积植物最多.洞庭湖湿地不同高程典型植物群落生态型组成为:阳性、旱生、中生、碱性,中性、非淤积型植物主要分布于高、中程区,淤积植物主要分布于低程区;阴性、耐阴性、酸性、碱性、非淤积型植物随高程的递增而递增.在洞庭湖湿地,能同时适应洪水和泥沙淤积胁迫的生长型和生活型所占比例较高.水分是决定不同植物生态型分布的关键因子,在湿地高程区分布的物种更多,植物生态型更丰富.

The relationship between plant community structure and its environment by analyzing plant life forms and plant ecotypes has important significance for tbe occurrence, development and succession law of plant community. An investigation was made on the species life form and ecotypes of wetland plants in Lake Dongting wetlands. Herbs are the dominant growth form, followed by lianas, but trees are scarce. Theropbytes are major life forms, followed by geophytes and hemicryphytes, and pbanerophtes and chamaephytes were the least in Lake Dongting wetlands. The proportion of phanerophtes and chamaephytes in different communities and the same life in different plant communities increased with the elevation. Hygrophytes is major ecotype according to water requirement. Neutral soil plant is dominant ecotype based on soil pH requirement. Heliophytes is dominant ecotype according to light intensity demand. The depositions of plants are major ecotype according to responses sediment ubrial. Heliophytes, xerophyte, mesophyte, alkaline plant, neotrophilous and burial intolerant plant distribute mainly in low-elevation sites. Shade-demanding plant, shade-enduring plant, acid plant, alkaline plant and burial intolerant plant species also increased with elevation. In Lake Dongting wetlands, the proportion of plants which can adapt to both flooding and sedimenting processes simultaneously is high. Water is the key factor determining the plant distribution of different ecotypes. Species and ecotypes were more diverse in intermediate- and high-elevation sites.