帽儿山3种森林生态系统土壤动物与土壤呼吸及其相互关系研究

Analysis on soil animals,soil respiration and the correlation in three forest ecosystems in Maoershan

土壤呼吸是森林生态系统碳循环的关键过程,土壤动物可通过自身代谢及影响微生物活动调控土壤呼吸,因此研究土壤动物与土壤呼吸的相互关系对进一步揭示生态系统碳循环的规律和机理具有重要意义。通过野外定点,以帽儿山3种森林生态系统的土壤呼吸及土壤动物为研究对象,探讨不同森林生态系统的土壤呼吸、土壤动物个体密度和生物量的时间变化规律及二者相互关系。结果表明:(1)3种森林生态系统土壤总呼吸速率与土壤异养呼吸速率均呈现先增强后减弱的时间动态变化(P<0.05),且不同森林生态系统土壤异养呼吸速率差异显著(P<0.05),表现为硬阔叶林最高,红松人工林最低;(2)3种森林生态系统土壤动物生物量也具有显著的时间动态变化(P<0.05),均在9月份达到最大,且不同森林生态系统土壤动物个体密度显著不同(P<0.05),蒙古栎林土壤动物个体密度显著小于红松人工林与硬阔叶林;(3)通过回归分析可得,土壤动物数量及生物量的增加抑制了土壤呼吸速率,尤其在生长季初期、末期。研究表明土壤动物可通过抑制微生物生命活动和降低根系呼吸从而对土壤总呼吸及异养呼吸产生负反馈作用,三者是不可分割的整体,与土壤温度、水分等环境因子共同调控着土壤呼吸。

Forest ecosystem is the largest organic carbon pool in terrestrial ecosystem,and its slight changes may cause significant variations in global climate.Soil respiration is the key ecological process of carbon cycle in forest ecosystem,which has a great influence on global climate change.Soil animals,as the important consumers of material cycle in the ecosystem,can regulate soil respiration the help of their own metabolism and affecting microbial activities.Therefore,study of the correlation of soil animals and soil respiration is of great significance to further reveal the law and mechanism of carbon cycle in ecosystem.Based on field experiment and indoor analysis,we chose soil respiration and soil animals in three forest ecosystems of Korean pine plantation forest(HS),Mongolian oak forest(MGL),and Hard-wood forest(YK)in Maoershan as the research object,and discuss the temporal variation and correlation between soil respiration as well as individual density or biomass of soil animals in different forest ecosystems.The results showed that:(1)the total soil respiration rate of the three forest ecosystems increased at first and then decreased(P<0.05),with the lowest value appearing in October.The soil heterotrophic respiration rate also showed significantly temporal dynamic change(P<0.05).The difference of soil heterotrophic respiration rate among different forest ecosystems was significant(P<0.05),which was the highest in Hard-wood forest and the lowest in Korean pine plantation forest.(2)The soil animal biomass and individual density of the three forest ecosystems also had notable temporal dynamic changes(P<0.05).The change trends of soil animal biomass and individual density were different,but they all had the maximum values in September.The individual density of soil animals in Mongolian oak forest was much lower than that in Korean pine plantation forest and Hard-wood forest.(3)Through regression analysis,the increase of the number and biomass of soil animals inhibited the soil respiration rate,especially at the beginning and end of the growing season.And the correlation between soil respiration and soil animals in Korean pine plantation forest was different from that in Mongolian oak forest and Hard-wood forest.It could be concluded that soil animals could produce negative feedback on total soil respiration and heterotrophic respiration by inhibiting microbial life activities and reducing root respiration.Soil animals,soil microorganisms and plant roots are an inseparable whole,which together with soil temperature,water and other environmental factors regulate soil respiration.