草原生态系统C:N:P化学计量驱动蝗灾发生的水分调控机理

Locust plague have given human lots of catastrophic damages in history. People all over the world conrespondingly have put great endeavour to overcome this hamful disaster in company with locust outbreaks. Recently, scientists come from China and the United States published a hypothesis named "Low plant nitrogen can stimulate locust outbreaks in heavy grazed sites" in Science magzine. In order to test this hypothesis and revise it when possible, and based on Chinese traditional knowledge and our field observation, we plan to conduct a serious experiments in the Inner Mongolis grassland ecosystem, and in particular we will focus on the ecological significances of soil water and precipitation pattern in regulating the C:N:P stoichiometric effects of plant (and soil) on the population dynamics and outbreak of a major hamful grasshopper (locust) species Oedaleus asiaticus. This project may provide useful data to enhance our understanding of multitrophic interactions in term of C:N:P stoichiometric relationships under the background of global climate changes. We intent to discover some key time of locust life history and especially to find the critical role of water regulation. Our studies may also provie scientific basse in decision-making involveing to grassland ecosystem managements.

历史上蝗灾曾带给人类巨大灾难。蝗灾防控一直是困扰各国政府和人民的世界性难题。最近中美两国科研工作者联合提出了"放牧驱动草原蝗灾发生的植物低氮调节"假说,为我们认识蝗灾生态机理、高效开展蝗灾防控提供了十分有益的启发。但是根据传统知识和我们野外观察，这一调节过程可能受水分直接制约。为了检验这一假说并在实验支持下对其加以修订，本项目拟于内蒙古草原生态系统中研究近20年来最主要的成灾蝗种"亚洲小车蝗"在放牧压力变化形成的土壤水分梯度上同植物之间的C:N:P化学计量相互作用，并特别聚焦于水分在调节"土壤-植物-蝗虫"关系中的关键性生理生态作用。本研究将结合自然水分梯度和降水格局变化、多物种群落效应和单种食料植物同蝗虫的细致关系、蝗虫生活史对策和生理生化机制（分子机理）相互适应等方面，通过进行几个紧密联系、互补互证的野外到室内实验，去研究我国北方草原放牧驱动蝗虫-植物相互作用中的土壤水分和降水调控过程