宁夏天然草原甲虫群落多样性及其对环境因子的响应

The desert steppe and typical steppe are important grassland types in Ningxia, which supporting species diversity of plant and animal in the Northwest China. Furthermore, natural grassland plays a key role in the ecosystem, ecological balance, and sustainable development of environment. Beetles have the largest species number in insect, which also have a wide distribution and multiple function groups. In the present project, two trophic levels include plant and beetles are selected to sample through field investigation and control test. Then, the relationship between beetles and plant is analyzed by correlation and regression method. Furthermore, the responses of beetle to environment are determined, which aim to reveal the mechanism of interaction of beetle and environment. Finally, the effects of ecosystem function and processes on species diversity of beetles are clarified, and beetles’ response to the vegetation and others external environment would be studied. Change mechanism and change trend of the beetle diversity under the environmental conditions would be discussed. Furthermore the response of species diversity on ecosystem function and process would be discussed. This study will provide a reliable scientific basis in sustainable management and adaptative management of grasslands, ecological function and service, and integrated pest management.

宁夏天然草原类型主要包括荒漠草原和典型草原，在我国西北地区的生物多样性保育和维持中发挥着重要的作用，而且对生态系统稳定性及环境可持续性有着重要的支持作用。本项目以物种数量最多、分布最广、功能群复杂的甲虫为研究对象，基于草原植被和甲虫两个营养级层面，通过野外调查和控制试验，分析甲虫和植物多样性与群落结构特点及其变化趋势，从群落角度研究甲虫多样性及其群落组成对植被等外部环境的响应，探讨甲虫多样性在环境条件变化下的改变机制，进而阐释生物多样性对生态系统功能和过程的响应。研究结果将为实现草地可持续性生产和适应性管理、生态系统功能与服务，以及草原有害生物防治提供可靠的科学依据。

生物多样性是生态学研究的热点问题，草原生态系统对于保护生物多样性意义重大，然而不同草地类型的差异将会影响物种分布与环境之间的关系，以步甲为代表的地表节肢动物对于环境变化尤为敏感。因此，本研究采用巴氏罐诱法于2017至2019年对宁夏三种草原类型中甲虫的组成及分布进行监测；在区域尺度上分析了荒漠草原、典型草原、草甸草原的甲虫的群落组成、步甲丰富度、种群多样性及功能多样性的分布差异。最后探究了驱动步甲分布的主要环境因子及其指示性物种对环境变量的响应机制，为宁夏地区草地管理，丰富草原生态系统的稳定性、生产力、环境监测及维持高水平的生物多样性提供参考依据。.1. 共捕获甲虫标本13630号，分属于18科74种，科级水平上，步甲科有26种，9807头，占比71.95%；拟步甲科有13种，1701头，占比12.48%，达到绝对优势水平。步甲科在典型草原与草甸草原为绝对优势科，占比分别达80.8%和77%，拟步甲科在荒漠草原为绝对优势科，占比为49.52%。.2. 共捕获步甲标本9807号，隶属于12属26种，长叶步甲Carabus vladimirskyi、雕步甲Carabus glyptoterus为草原优势步甲物种。从荒漠草原-典型草原-草甸草原，步甲个体数发生高峰期均在8月。α多样性表明，草甸草原与典型草原的物种多样性均显著高于荒漠草原（P<0.0001），荒漠草原步甲群落多样性最低。.2.CCA（对应典范分析）及广义加性模型分析表明气温、土壤温度、降雨量是驱动步甲分布的主要环境因子，其中，土壤有机质、温度、海拔、降雨量是驱动典型草原步甲物种分布的主要环境因子；土壤含水量、温度、降雨量、全氮、枯落物是影响草甸草原步甲分布的主要因子。.3.雕步甲为荒漠草原的唯一指示性物种，长叶步甲、雕步甲与直角通缘步甲为典型草原的指示性物种，长叶步甲与强足通缘步甲为草甸草原的指示性物种。