荒漠区一年生植物层片的组织格局与生态适应模式

在阿拉善荒漠及其邻近地区 ,有多种一年生植物种群可组成荒漠与绿洲生态系统的恒有性植物层片。本项研究利用样地调查与统计资料 ,取得了多种一年生植物层片物种组成的研究结果 ;在吉兰泰盐湖地区、腾格里沙漠东南部、雅布赖低山区、孪井滩地区、祁连山山麓、额济纳绿洲等地 ,对一年生植物种群生物产量的季节与年度间的波动性进行了调查和测定 ,并与相关的气象资料做了比对分析 ,获得了气候年、季变化与一年生植物层片动态的相关性认识。据此 ,划分了一年生植物层片的生态类型。荒漠与绿洲生态系统中 ,主要的一年生植物层片有 :.荒漠夏雨型一年生禾草类植物层片 ,荒漠一年生杂草类植物层片 ,沙漠一年生沙生植物层片 ,盐漠一年生盐生植物层片 ,绿洲草甸一年生植物层片 ,绿洲胡杨林一年生植物层片 ,柽柳灌丛一年生植物层片 ,绿洲农田一年生杂草植物层片等。多数一年生植物种是在荒漠优势植物株丛间的裸斑土壤种子库中 ,有丰富的种子储备 ,利用夏季较为集中的降雨迅速萌发生长到结实 ,完成一个短暂的生活周期。也有些一年生植物在沙质土、盐渍土、草甸土等特异性生境中各自具有有效的生态适应机制 ,组成沙漠、盐漠、绿洲林地与草地的一年生植物层片。这些一年生植物层片的组织格局 ,生态适应模式 ,生态功能

The Organization Patterns and Ecological Adaptive Modes of Annual Plant Synusia in Desert Regions

In Alashan desert and nearby areas, there are many annual plant populations which formed permanent plant synusiae. By the sample sites investigation and data statistics, the species compositions of many kinds of annual plant synusiae were resulted. At the Jilatai Salt Lake region, southeastern part of Tenggeli Desert, foot of Yabulai Mountain, Luanjingtan area, foot of Qilian Mountain, and Ejina Oasis, the seasonal and annual biomass dynamics of annual plant populations were investigated and surveyed. By analyzing the above results and meteorological data, the relationships between the annual plant synusia dynamics and the seasonal and annual meteorological changes were revealed. According to the above results, ecological types of annual plant synusiae in the desert and oasis eco-systems were classified, they mainly were: annual grass synusia growing in desert where rains mainly occur in summer, annual forb synusia growing in desert, annual plant synusia adapted to growing in sand desert, annual plants synysia adapted to growing in saline desert, annual plant synusia growing in oasis meadows, annual plant synusia growing in oasis of Populus euphratica forest. annual plant synusia growing among the Tamarix elongaata shrubs, and annual plant synusia growing in oasis farmland, etc. Most of the annual plants have a rich seed storage in the soil seed bank of necked areas between shrubs, and these seeds can germinate, grow and fruit rapidly during the rainy summer, and then finish their shorter life cycle. Some annual plants respectively have special efficient ecological adaptation mechanisms, can grow in the peculiar eco-environments of sandy soil, saline soil and meadow soil, and form annual plant synusiae in desert, saline desert, oasis forest and range land. The differences of the organization patterns, ecological adaptive modes, ecological functions and values among these synusiae reflect the important characteristics of bio-diversities in desert and oasis, about which, analysis and evaluations were taken in the paper.