不同利用方式对典型草原优势植物生物量的影响

Effects of land use on biomass of dominant plants in typical steppe

植物个体性状是表征草原生态系统功能和结构的指示器。本试验对内蒙古典型草原优势植物种(克氏针茅和糙隐子草)在不同利用方式的响应进行了研究,物种地上生物量和分配比例及地下生物量作为研究指标,分析对比自由放牧,1995年围封和2003年围封3种不同利用方式对克氏针茅和糙隐子草生物量的影响。研究结果表明,不同利用方式显著影响了两种优势植物种地上、地下生物量(P<0.05)。放牧显著降低了两种植物地上茎、叶和种子生物量(P<0.05),但显著增加了两种植物的地下根系生物量(P<0.05);围封区(1995和2003年围封)C3/C4比率显著高于自由放牧区。

Plant characteristics can indicate the function and structure of grassland ecosystems.A field experi-ment was conducted to examine potential impacts of different land management systems on the dominant grass-land species （Stipa krylovii and Cleistogenes squarrosa ）in a typical steppe in Inner Mongolia,China.The characteristics of the two dominant species were described under three land management systems;continuous grazing,1995 enclosure and 2003 enclosure （livestock excluded）.Above-ground biomass,the distribution of a-bove-ground biomass and below-ground biomass are reported.Land management significantly affected above-and below-ground biomass of both species （P 〈0.05 ）.Compared with the enclosed areas （1995 and 2003 ）, continuous grazing reduced total above-ground biomass,leaf biomass,stem biomass and seed biomass of both species （P〈0.05）but increased below-ground biomass of both species （P 〈0.05）.The C3/C4 ratio was higher in enclosed areas than under grazing （P〈0.05）.