内蒙古锡林河流域草原植物种群和功能群热值研究

选取内蒙古锡林河流域具有代表性的羊草、大针茅、羊草草甸草原群落类型，每个群落包括未退化、轻度退化、中度退化和重度退化不同退化程度的样地，对其出现的主要植物种群热值进行研究，并分析不同功能群的热值变异。结果表明，研究区出现的60个植物种平均热值为（17．29±0．91）kJ／g，变异系数为5．4％；生活型功能群中，灌木的热值最高，多年生禾草显著高于一二年生植物（P〈0．05），半灌木和多年生杂草介于二者之间；水分生态类型功能群之间在热值上没有明显差异；不同科之间热值有显著差异，禾本科、豆科、菊科植物热值较高，藜科植物平均热值最低。

Caloric Values of Steppe Plant Populations and Functional Groups in Xilin River Basin of Inner Mongolia

Caloric values of main plant population in two typical steppes respectively dominated by L.chinensis or S.grandis and one meadow steppe dominated by L.chinensis including of four degraded intensities sites(undegraded,relatively light,moderate and heavy degraded) in each steppe types were investigated in Xilin River Basin,Inner Mongolia.The mean caloric value of 60 species,taking into account three steppe types and four grazing degraded intensities studied,was 17.29 0.91 kJ g-1 with a CV of 5.4 %.Shrub had the highest value among groups classified by life forms.The mean of perennial grasses was significant higher than that of annuals and biennials(P<0.05),the subshrubs and perennial forbs were in the midst.No statistically significant differences were found among the caloric values of the different plant groups based on water ecological types including of xerophytes,mesoxerophytes,xeromesophytes and mesophytes.Different families showed apparent difference in caloric value.The higher caloric values were found in Gramineae,Leguminosae and Compositae,while Chenopodiaceae has the lowest value.