长期耕作影响下东北黑土农田土壤动物多样性的维持、保护及其生态服务功能研究

Biodiversity research in farmland is one of most important and significant works to national ecological safety in the world. Soil environmental degradation is a key ecological problem in farmland, and it would be harmful to soil biodiversity. Taking the key fund support direction of NSFC “soil biodiversity and its function” as a guide, this project uses soil animal as materials in black soil region of Northeast China to study how to keep, protect and utilize its biodiversity in the farmland degeneration environment. Basing on profoundly knowing the process and the mechanism of “the farmland cultivation influence - soil animal response - biodiversity maintenance” in the multi-scale farmland field, we hope to focus on some key scientific questions to understand the farmland soil animal biodiversity maintenance reason, and simultaneously appraise the conservation tillage effect on soil animal biodiversity and discuss the different body length soil animal's ecological service function to the farmland ecosystem in the long-term cultivation influence farmland. The project plans to resolve three main scientific questions as followed: 1) How does the soil animal in farmland respond to the environmental variation, and then to maintain its biodiversity? 2) Is the conservation tillage helpful to restore and protect soil animal biodiversity in the long-term cultivation farmland? and how about the effects? And 3) How does the soil animal biodiversity maintenance influence the farmland ecosystem function? Theoretically, the project will contribute some new scientific opinions to the farmland soil animal biodiversity maintenance, the protection and the ecological service function, and develop farmland biodiversity theory. In the national demand, it will reasonably provide the scientific support for the slow-down of agricultural development disadvantageous ecology influence, and benefit the farmland biodiversity protection in our country in the future.

项目以重点基金支持方向“土壤生物多样性及其功能”为指南，针对农田生态环境退化引发的生物多样性保持这一重大生态问题，以土壤动物为对象，立足东北黑土区，突出田间多尺度情景，深刻认识“农田耕作影响-土壤动物响应-生物多样性维持”过程与机制，解决长期耕作影响下农田土壤动物多样性维持的关键科学问题，同时评估保护性耕作对土壤动物多样性保护价值并探讨不同体长土壤动物的生态服务功能。项目拟解答三个主要科学问题：1）农田土壤动物是如何响应环境变化进而维持其多样性的？ 2）保护性耕作是否有助于长期耕作农田各类群土壤动物全面恢复与保护？价值如何？3）土壤动物多样性的维持对农田生态系统功能实现有何影响？理论上，项目预期在农田土壤动物多样性维持、保护和生态服务功能上提出新科学见解，发展农田生物多样性学科理论；国家需求上，为减缓与规避农业发展不利生态影响提供科学依据，为国家应对农田生物多样性保护与利用等提供科学支持。

针对东北黑土农田土壤动物多样性部分丧失、土壤生态服务功能受到影响的实际，结合学科前沿，项目组开展“东北黑土农田土壤动物多样性维持、保护及其生态服务功能”研究。本项目关注的关键科学问题：农业生产活动干扰频繁条件下，黑土农田土壤动物物种间的相互作用关系及其群落构建过程；保护性耕作对土壤动物多样性的恢复作用； 黑土农田土壤动物间的营养关系，不同体长动物功能群在土壤生态服务功能中的贡献及机制。项目主要研究内容包括四方面：1）黑土农田土壤动物食性及其营养关系；2）常规耕作黑土农田土壤动物多样性空间格局；3）保护性耕作黑土农田土壤动物多样性变化；4）不同体长土壤动物功能群土壤生态服务功能的差异。过去5年，项目完成以下任务：1）利用稳定同位素技术，确认了黑土区主要土壤动物及其相关作物植株上的节肢动物的食性，土壤动物食性主要分为捕食、植食、腐食、杂食和菌食类别，农田各类土壤动物的食物来源主要是根系和凋落物，来自植株地上部分的食物很少；2）建立了土壤动物多样性格局变化长期监测平台，解析了东北黑土区农田土壤动物群落构建与维持机制，发现土壤动物群落内物种共存为显著的非随机性，田间尺度黑土农田土壤动物群落普遍具有空间自相关性；3）依托保护性耕作长期定位试验样地开展保护性耕作对土壤动物多样性的影响，明确不同耕作方式下土壤动物多样性的变化特征，显示保护性耕作有提高土壤动物多样性的趋势；4）结合控制实验，探讨了不同耕作方式下蚯蚓、螨类、跳虫和线虫等对土壤有机碳、温室气体排放、光合碳分配等的影响，显示体型较大的蚯蚓和个体密度丰富的线虫在与碳相关生态过程实现中作用重要。截止2019年末，项目组在Soil Biology & Biochemistry、Geoderma 和Applied Soil Ecology等土壤生物学及相关刊物共发表项目标注（41430857）SCI检索论文68篇，中文核心期刊论文8篇。