宁夏东北部典型荒漠草原植物群落与土壤养分特征

以宁夏东北部荒漠草原为研究区,采用野外样方调查、采样和室内植物鉴定、土壤样品测定等方法,探析研究区内植物群落物种组成与土壤养分特征,以及植物多样性指数与土壤养分的相关关系,以期为中国荒漠治理、生物资源保护与可持续性利用提供依据。结果显示:(1)研究区植物共86种,隶属61属21科,其中禾本科(18种)、豆科(16种)、菊科(13种)和藜科(11种)植物占总物种数的67.44%;(2)研究区土壤总体上呈碱性,pH值平均为8.81,全氮、全磷、有机质的质量分数(0-10 cm土层)分别为0.07-0.54、0.16-0.51、0.51-6.24 g·kg^-1;(3)研究区植物多样性指数中的Margalef丰富度指数和Shannon-Wiener多样性指数与土壤pH值呈显著负相关,与其他土壤养分的相关关系未达到显著水平,其他植物多样性指数与土壤养分的关系均未达到显著水平。研究表明,宁夏东北部荒漠草原植物种类少,禾本科、豆科植物优势明显,土壤养分条件差,土壤全氮、全磷、有机质对植物多样性指数的影响不大。

Characteristics of Plant Communities and Soil Nutrients in Desert Steppe of Northeastern Ningxia

Taking the desert steppe in northeastern Ningxia as study area,field sample investigation and plant identification,soil sample analysis in experiment has been adopted to explore plant community,soil nutrient characteristics and the relationship between plant diversity index and soil nutrient.The results showed that,(1)There were 86 species belonging to 61 genera and 21 families in the study area.Among them,species in Gramineae(18 species),Leguminosae(16 species),Compositae(13 species)and Chenopodiaceae(11 species)accounted for 67.44%of the total species.(2)The soil in the study area was generally alkaline,with an average pH value of 8.81.The mass fractions of total nitrogen,total phosphorus and soil organic carbon were 0.07?0.54 g·kg^-1,0.16?0.51 g·kg^-1 and 0.51?6.24 g·kg^-1,respectively in 0?10 cm soil layer.And(3)the Margalef richness index and Shannon-Wiener diversity index had significant negative correlation with soil pH value,but had no significant correlation with other soil nutrients,while the relationship between other plant diversity indexes and soil nutrients was not significant.The results showed that the plant species were not rich,and Gramineae and Legumes were obvious dominant.Soil nutrient conditions was poor,and the correlation between plant diversity index and total nitrogen,total phosphorus,soil organic carbon was not significant.