不同改良措施对退化割草场物种多样性及群落生产力的影响

Effects of Different Improvement Measures on Species Diversity and Community Productivity of Degraded Mowing Grassland

以内蒙古锡林郭勒典型草原退化割草场为对象,通过切根、施肥、切根+施肥的改良方式,研究退化割草场植物群落及根系对不同改良措施的响应。结果表明:施肥和切根对典型草原区退化割草场植物多样性无显著影响;施肥+切根措施可显著提高群落地上生物量(P<0.05),但受年际间气候变化(如降雨)的影响;施肥有利于以禾本科植物为优势种的群落生物量向地上分配,而切根则有利于向地下分配。综上所述,在典型草原区退化割草场改良过程中,单独进行切根或施肥对物种多样性影响较小,但在切根的基础上同时施肥能够有效提高群落生产力。

This study took typical degraded grassland mowing in Xilingol,Inner Mongolia as the research object,and studied the response of plant community and root system of degraded grassland to different improvement measures by cutting roots,fertilizing,cutting roots and fertilizing.The results showed that:(1)fertilization and root-cutting had no significant effect on the plant diversity of degraded mown grasslands in typical steppe areas;(2)fertilization and root-cutting could significantly increase aboveground biomass of the community(P<0.05),but affected by inter-annual climate change(such as rainfall);(3)fertilization was beneficial to the aboveground distribution of biomass in the communities with gramineae as dominant species,while cutting was beneficial to the underground distribution.In summary,in the improvement process of degraded grassland in typical grassland areas,root cutting or fertilization alone had little impact on species diversity,but simultaneously applying fertilizer on the basis of cutting root can effectively improve community productivity.Therefore,root cutting and fertilization can be used as one of the effective ways to restore and improve degraded grassland.