森林土壤动物摄食活动对全球气候变化的响应

Forest ecosystems are strongly dominated by temperature, and global warming is expected to have a particularly strong impact on forest vegetation ecosystem, however, the potential impacts of climate change on the soil biota have received considerably less attention than other ecosystem components, and there are very few predictions concerning climate change responses of soil fauna. Soil fauna is an important component of soil ecosystems, which plays an important role in decomposition of biological remains, affecting soil properties and enhancing material recycling and energy conversion in the soil.. To understand the impacts of global climate change on soil faunal feeding activity is essential to achieve soil fauna adapting to the changed condition. Therefore, an transplant experiment was carried out in a mountain. To simulate climate changes was made by using soil cores transplant method, meanwhile, simulate different precipitation were made based on global warming. After removing soil fauna in soil cores by freezing method, different soil fauna group with different density were added in soil cores, and to test soil faunal feeding activity by using bait-lamina test, so as to get to known feeding activity intensity, meanwhile, the relationships between soil physical, chemical properties and feeding activity was studied. Those result can help us get to know the adjustment ability of soil food chain on nutrition cycle based on the global climate change, and to provide basic theory on consumers of food chain which deal with global climate change.

全球气候变化所带来的影响越来越多的被人们所揭示，土壤动物作为森林生态系统物质循环和能量流动的关键环节，其摄食活动是否也受到全球气候变化带来的影响受到广泛关注。本项申请试图研究全球气候变化对森林土壤动物摄食活动的影响，利用“土柱移位”法将土柱从高海拔移到低海拔地区来实现模拟气候变暖，并在此基础上模拟大气降水量的不同变化，在“低温冷冻”法原位剔除土柱中的土壤动物后，通过往土柱中添加不同密度的土壤动物种群试验处理，利用bait-lamina法研究大气变暖/降水量变化情形下的土壤动物摄食活动强度、时间特征以及不同土层的取食特点，分析土壤动物摄食活动与土壤理化性质、土壤脱氢酶活性的相关性，从而为了解全球气候变化对土壤食物链应对养分循环调整的能力，以及食物链的消费群体自身是如何应对全球气候变化提供理论基础。

全球气候变化所带来的影响越来越多的被人们所揭示，土壤动物摄食活动是否也受到全球气候变化带来的影响受到广泛关注。本项目探讨全球气候变化对森林土壤动物摄食活动的影响，其结果有助于了解土壤食物链应对养分循环调整的能力，以及食物链的消费群体自身是如何应对全球气候变化提供重要的理论基础。试验利用“土柱移位”法将土柱从高海拔移到低海拔地区来实现模拟气候变暖，并在此基础上模拟因全球气候变暖造成的5种降水（以0.5P、0.75P、P、1.25P、1.5P）情形，通过往土柱中添加不同密度的土壤动物种群，即，跳虫（1415头/m2、4246头/m2、12739头/m2）、蜱螨（1699头/m2、5622头/m2、16985头/m2）、蚯蚓（57头/m2、170头/m2、283头/m2）进行试验，利用bait-lamina法研究大气变暖/降水量变化情形下的土壤动物摄食活动强度、时间特征以及不同土层的取食特点。主要结果包括：（1）土壤动物密度和类群数均以低海拔最高，分别为6.53×104只·m－2和66类，以高海拔最低，分别为1.35×104只·m－2，共38类；（2）气候变暖后，蚯蚓的取食活动随着土壤深度的增加而下降。蜱螨类主要集中在土表，摄食活动对气候变暖较敏感，气温变暖促进蜱螨类的取食。跳虫密度对取食强度的影响较小，但气候变暖对跳虫在土层中的取食位置有明显的影响，同时，气候变暖后，跳虫首次取食的时间较低温条件下早，气温升高促进了跳虫在深层土壤的取食率。（3）降水量变化后，蚯蚓在正常降水（P）条件摄食活动较其他降水处理高，同时，高强度摄食活动与高密度的处理并不存在正相关性，高摄食活动基本在中低密度处理观察到。蜱螨类对降水变化的响应较蚯蚓慢，在试验后期，其取食率迅速增加。降水增加在一定程度上增强了蜱螨的取食率，干旱则不利于其取食。而干旱环境有利于跳虫的摄食活动，随着降水量的增加，跳虫的摄食活动受到一定的抑制，跳虫的取食时间基本在试验的中后期，取食位置主要分布于中层土壤以上。