土壤纤毛虫群落对退耕还林生态恢复的响应及其对退还效果的评价

The ciliated protozoa are the most complex and highly differentiated unicellular animals and play a very important role in soil ecosystem，and are extremely sensitive to ecological changes because of their special characteristics such as numerous species，huge standing crops and productions，tiny single-celled individuals，thin cell membranes，a rapid growth，a short generation time，a great rate of community succession and a wide distribution，etc. The soil ciliate communities in the typical areas of conversion of cropland to forest in various periods and patterns and in the control areas in Gansu will be studied qualitatively and quantitatively，and the related environmental factors will be measured and calculated simultaneously. The situations and mechanisms of the response of the communities to the conversion will be investigated based on comparative analysis on the community characteristics and comprehensive analysis on the correlation between the community characteristics and the environmental factors，and the ecological effects of conversion of cropland to forest will be assessed based on the response. It is expected that the research work of this project and its results will provide protozoological and ecological references for an optimum design and implementation of the follow-up project of conversion of cropland to forest，and accumulate fundamental data for future investigation on the functions of soil ciliates in the process of ecological restoration resulted from conversion of cropland to forest，and offer references for research work on soil microorganisms and metazoans in the areas of conversion of cropland to forest as well.

纤毛类原生动物是最复杂和最高等的单细胞动物，是土壤生态系统中十分重要的动物类群之一，因其物种繁多、现存量和生产量巨大、个体微小、细胞膜纤薄、生长繁殖快、群落演替迅速、分布广泛等特点而对生态变化极为敏感。本项目申请人拟对甘肃省不同时期、不同模式典型退耕还林区及对照区的土壤纤毛虫群落开展定性和定量研究，同时对土壤环境因子进行测试。在比较分析不同时期、不同模式退耕还林区和对照区纤毛虫群落特征及综合分析群落特征与土壤环境因子间的相关关系的基础上，探讨纤毛虫群落对退耕还林的响应状态和机制，并据此对退耕还林的生态效果进行评价。本项目的研究工作及其结果将为退耕还林后续工程的优化设计和实施提供原生动物学和生态学参考依据，为下一步探讨土壤纤毛虫在退耕还林生态恢复过程中的功能和作用积累基础资料，也可为退耕还林区土壤微生物和后生动物的研究工作提供参考。

退耕还林还草工程是一项意义重大的生态工程。退耕还林还草导致地上生态环境发生的重大变化必然影响到地下，引起土壤动物群落在组成、结构和功能方面的响应。纤毛虫是最复杂和最高等的单细胞动物，是土壤生态系统中十分重要的动物类群之一，因其物种繁多、现存量和生产量巨大、个体微小、细胞膜纤薄、生长繁殖快、群落演替迅速、分布广泛等特点而对生态变化极为敏感。本项目对甘肃省境内5个研究样区（东部、东南部、西南部、中部、河西走廊）的退耕还林还草样点和对照样点的纤毛虫群落特征（物种组成，时空异质性，群落相似性）和环境因子（植被，土壤理化因子）进行了研究。在此基础上，综合分析了不同时期和不同模式退耕还林还草区及相应对照区土壤纤毛虫群落特征参数，了解和掌握了土壤纤毛虫在群落水平对退耕还林还草生态恢复的响应状态。基于对土壤纤毛虫群落特征与环境因子间的相关关系的综合分析，探讨了土壤纤毛虫在群落水平对退耕还林还草生态恢复的响应机制。本项目的研究工作及其结果将为退耕还林还草后续工程的优化设计和实施提供原生动物学和生态学参考依据，为进一步探讨土壤纤毛虫在退耕还林还草生态恢复过程中的功能和作用积累基础资料，也能为退耕还林还草区土壤微生物和后生动物的研究工作提供参考，还可为土壤环境监测和生物-生态修复提供技术和方法。