草地生态系统土壤微生物量及其影响因子研究进展

Advances in Researches on Soil Microbial Biomass of Grassland Ecosystems and Its Influencing Factors

草地作为陆地生态系统的主体类型之一,受到人类活动和全球变化的广泛影响。这些因素在直接影响草地生态系统地上植被生长和群落动态的同时,还直接或间接地影响着草地生态系统的各种地下生态过程。土壤微生物是指示草地生态系统各地下生态与生物地球化学过程对外部干扰响应的良好指标,其中微生物量是土壤微生物活性和大小度量的重要参数,是土壤有机质中最活跃的组分之一,能够敏感地反映土壤生态系统水平的微小变化,在各种土壤生化过程研究中具有非常重要的意义。研究综述了自然因子(土壤温度、土壤湿度、pH值)、人为干扰(放牧、开垦、施肥)和全球变化(大气CO2浓度升高、气候变暖)对草地生态系统土壤微生物量影响的研究进展,并指出目前的研究由于基础薄弱、研究样地间的差异以及各研究处理间的差异,土壤微生物量对各种干扰的响应仍存在很大的不确定性,在今后的研究中应加强长期性的野外定位试验研究、多因子的综合控制实验研究以及N输入对微生物量影响的研究等,并进一步完善和发展测量微生物量的新技术和新方法。

As one of the main terrestrial ecosystems,grassland ecosystem has suffered the extensive effects from human activity and global change.These effects not only have an influence on aboveground process such as plant growth and plant community dynamics,but also exert a profound influence on multiple belowground processes simultaneously.Therefore,soil microorganism may be a good indicator to understand the response of the aforementioned belowground biological and biogeochemical processes to the changes of outside disturbances. Soil microbial biomass is an important parameter to character the soil microbe activity and size.Meanwhile,it is also the most active component of the soil organic carbon pool,and plays an important role in indicating the minute changes in soil system and is of great significance in the research of soil bio-chemical processes.Here the effects of natural factors（soil temperature,soil moisture and soil pH）,human disturbances（grazing,grassland rec-lamation and fertilization）and global changes（elevated CO 2 and global warming）on soil microbial biomass of grassland ecosystem are presented.So far,the researches about the effects of natural factors and external disturbance on soil microbial biomass still have a lot of uncertainties,so long-term field studies,multiple factors controlled experimentation and nitrogen input studies should be strengthened in the future studies.Besides,new technologies and methods to determine soil microbial biomass are also expected to be developed.