共和盆地塔拉滩不同类型草地群落组成与土壤特性

共和盆地塔拉滩草原植被3个代表性植物群落是短花针茅+青海固沙草群落、芨芨草群落和川青锦鸡儿灌丛群落.在19个样地95个样方植被群落和土壤调查的基础上,分析3个不同群落结构及土壤质地和养分含量变化特征,调查样地共出现植物32种,其中,川青锦鸡儿灌丛草地出现植物11种,芨芨草草地22种,青海固沙草草地21种.群落生物量和盖度表现为芨芨草草地显著大于青海固沙草草地,青海固沙草草地又显著大于川青锦鸡儿灌丛草地,青海固沙草是3类草地的优势种.0～20 cm的土壤粒度组成以细砂粒为主.川青锦鸡儿灌丛群落全N、P、K含量比青海固沙草草地和芨芨草草地的高,表现出明显表聚现象.芨芨草群落土壤有机质含量低,并有弱盐渍化,土壤可溶性盐含量达0.26 ms·cm-1.群落植被和土壤系统的适应性为退化草地修复提供依据.

Community Composition and Soil Properties of Different Grassland Types on the Tala Shoal in Gonghe Basin

There exist three most representative plant communities within the Tala Shoal in Gonghe Basin, including Stipa breviflora and Orinus kokonorica grassland, Achnatherum splendens grassland, and Caragana tibetica shrubland. Field data of plant and soil investigation from 19 samples plots in 95 quadrats (1 m×1 m) was used to explore the community composition, soil texture and nutrient status of the three communities. Up to 32 plant species in total were found in the sample plot, with 11, 22 and 21 plant species in C. tibetica shrubland, A. splendens and S. breviflora grasslands respectively. The plant biomass and coverage was higher in the A. splendens grassland than in the O. kokonorica grassland, and the C. tibetica shrubland had the lowest plant biomass and coverage among the three communities, with O. kokonorica the dominant plants. The soil content to 20 cm in different particle-size separates was dominated by the fine sand. The soil nutrient concentrations of P, K, and N were higher in the C. tibetica than in the other two communities as the result of accumulation phenomenon, while the soil EC in the A. splendens grassland was 0.26 ms·cm^-1 with poor nutrient and weak salinization. Plant communities and their soil adaptation may offer guideline for the rehabilitation of degradation grassland.