干旱荒漠区草地植物群落地上生物量时空分布对地下水的响应

Temporal and spatial distribution characteristics of aboveground biomass of grassland plant communities in an arid area

分析了塔里木河下游以芦苇为优势种群的草地植物群落地上生物量时空分布特征及其对物种多样性和地下水的响应。结果表明,1)在时间上,2007年群落地上生物量最高,达741.75g/m2;在空间上,群落地上生物量随垂直河道距离的增加显著减少。2)物种多样性与群落地上生物量呈显著正相关。3)地上生物量在地下水埋深<3m时较高,且地上生物量对地下水中的Mg-Cl盐含量最为敏感,群落耐盐上限在5.0g/L左右。

The temporal and spatial distribution characteristics of the aboveground biomass of the main constructive species of grassland plant communities in the lower Tarim River and their response to groundwater depth and chemical composition of groundwater were analyzed.The results showed that：1）The highest aboveground biomass of grassland plant communities was in 2005（up to 741.75g/m2）;Aboveground biomass in grassland plant communities diminished with increasing vertical distance from the river.2）There was a significantly linear relationship between diversity indices and aboveground biomass.3）Aboveground biomass of grassland plant communities was highest when the groundwater depth was less than 3m.The upper limit of salt-tolerance of grassland plant communities sensitive to Mg-Cl salt,was about 5.0g/L.