三江平原湿地植物物种空间分异规律的探讨

Spacial differentiation regularity of plant species in Sanjiang Plain wetland

研究了三江平原典型湿地在地形、水分等因素制约下的植物物种空间分异规律,包括垂直分异规律和水平分异规律。首先,按照地形和水分的分异组合特点,把湿地生境分为较干燥生境、季节积水生境和常年积水生境。然后,在各个生境内采用样方法和样线法调查植物物种。调查分为20世纪70年代、80年代和2003年3个时期,范围包括三江平原的典型湿地植物群落。数据分析时采用了生境组合法。即把3个不同的生境组合成一个水分(或地形)梯度带,根据频度和多度指标筛选出主要物种,然后按照其空间位置,列出主要植物物种沿水分梯度带的分布序列。研究发现:三江平原湿地不同生境的植物物种组合和垂直分异差别明显。较干燥生境的植被类型以岛状林群落为代表,乔木、灌木和草本植物层次分明。季节性积水生境的植被类型以小叶章群落为代表,是典型的湿草甸植物群落,垂直结构不明显。常年积水生境以毛果苔草群落为代表,植物群落层次也比较明显。植物物种水平分异规律,基本上可由植物物种空间分布序列图来代表。随着地势降低,水分增多,乔、灌植物,湿草甸植物,水生草本植物在特定的空间依次出现。

The paper emphases on the study of spacial differentiation regularity of plant species in Sanjiang Plain＇s representative wetland at the control of water and topography, including the uprightness differentiation regularity and the level differentiation regularity. First, according to the differentiation and combination characteristics of topography and water, the wetland is divided into three different ecological environments, rather dried ecological environment, seasonal seeper ecological environment and perennial seeper ecological environment. Then quadrate method and line intercept method are adopted to investigate plants in these ecological environments. The investigations were carded out during three periods in 1970s, 1980s and 2003. The investigation areas include all representative plant communities in Sanjiang Plain wetland. The innovation of the text lies in adopting combination ecological environment method. It is to say that three different ecological environments are connected into one water （or topography） grads strip, then main plant species are picked out by frequency and abundance, at last the spacial distribution chart of main plant species is lined up along with water grads strip. The study shows that plant combination and vertical direction differentiation are very distinct in different ecological environments in Sanjiang Plain wetland. In the rather dried ecological environment, preponderant vegetation is island forest community, and it has evidently hiberarchy with arbor, shrub and herbage in vertical direction. In the seasonal seeper ecological environment, preponderant vegetation is Calamagrostis angustifolia community that is typical wet meadow, but it has no evidently vertical hiberarchy. In the perennial seeper ecological environment, preponderant vegetation is Carex lasiocarpa community, and it has also clear hiberarchy in vertical direction. The spacial distribution serial chart of main plant species can stand for level differentiation regularity. Along with topography descending and water level ascending, Arbor plants, shrub plants, wet meadow plants and water herbage plants appear on their special positions.