Abstract: To clarify the different degrees of salinization how to influence the grassland plant community and carbon storage,we selected natural grassland,grassland-saline-alkaline transition zone,and saline-alkali land in Huihe Reserve for field investigation and sampling,and combined indoor analysis methods for testing and research. The results showed that with the intensification of grassland salinization,the composition of plant community structure tended to be simplified;the carbon storage of plants and ecosystems were all gradually decreasing. Besides,the topsoil organic carbon storage in grassland-saline-alkaline transition zone was the largest,followed by saline-alkali land,and the lowest was the natural grassland. The carbon storage of vegetation changed with different types,growth characteristics of aboveground plants,as well as soil physical and chemical properties. Also,the topsoil organic carbon storage was mainly affected by the interaction between aboveground plant types,soil moisture content,and different salinization degrees of grasslands. Turnover of the plants and change in soil pH can affect ecosystem carbon storage,especially soil pH can significantly affect topsoil organic carbon storage(P < 0.05). Therefore,the plant community and carbon storage in temperate meadow steppe were affected by the different salinization degrees of grasslands.

Key words: Huihe Reserve, Salinization, Temperate meadow steppe, Carbon storage, Plant community

摘要： 为阐明草地盐碱化过程中草地植物群落结构及碳储量的变化，以辉河保护区内的天然草地、草地-盐碱地过渡带和盐碱地为研究对象，采用野外调查采样结合室内分析的方法进行测试研究。结果表明随着草地盐碱化加剧，植被群落结构组成趋于简单化；植被碳储量和生态系统碳储量均逐渐下降，表层土壤有机碳储量表现为过渡带>盐碱地>天然草地。植被碳储量的变化主要与地上植被类型、植被生长特性和土壤理化性质有关；表层土壤有机碳储量的变化主要是地上植被和土壤水分与不同盐碱化草地相互响应的结果，其中，pH会显著影响表层土壤有机碳储量(P<0.05)；生态系统碳储量的变化受到植被更迭和土壤pH的影响。因此，温性草甸草原植被群落结构和碳储量均会受到草地盐碱化的影响。

关键词: 辉河保护区, 盐碱化, 温性草甸草原, 碳储量, 植物群落