提高森林资源质量是森林经营的永恒主题。飞播马尾松林是赣南主要森林资源之一，其面积占有林地总面积的21.4%，但因受季节性干旱胁迫的主要影响及严重水土流失背景导致的土壤退化、持水性能下降，不少飞播林林木长势差、林下植被稀少、林分功能低下，因此，本项目针对全球性气候变暖可能造成极度干旱或降雨量增加的背景下，以赣南兴国县的低效飞播马尾松林为研究对象，集成生态学、森林经营学、土壤学、水土保持学等学科的理论与方法，开展提高土壤蓄水保水能力、降水排斥和增加降水等措施的试验，通过对试验地的调查与样品测定，阐明土壤水分变化及其与土壤性质变化的耦合关系，探明植物根系、林木生长、林下植被恢复对土壤水分时空变化的响应，并通过土壤水分-植物-降雨系统的综合分析，揭示土壤水分变化对植物-土壤交互作用的基本机制，为赣南低效飞播马尾松林经营改造及进一步揭示我国南方季节性干旱胁迫对退化森林生态系统的影响机理提供科学依据。

Improving the quality of forest resource is the eternal theme of forest management. Aerially seeded Pinus Massoniana plantations (AS) is one of the main forest resource in southern Jiangxi province, which accounts for 21.4% of total forest land area. However, quite a few AS are growing worse, the understory vegetation are scarce, and stand functions decline, influenced by main effects of seasonal drought stress and soil degradation along with soil moisture capacity decreased under the background of severe soil erosion. Therefore, aimed at the possibility of extreme drought or increase of precipitation under the background of global climate change, this project takes the low-efficiency AS in Xingguo county of southern Jiangxi province as the research object, and then carry out kinds of experiments, such as measures of improving the soil moisture reserve and water-holding capacity, increasing the precipitation, and rainfall exclusion experiment, by integrating theories and methods of ecology, forest management, soil science, soil and water conservation, etc. In this project, we can expound the change of soil moisture and the coupling relationship between changes of soil properties and soil moisture, explore the temporal-spatial variations of soil moisture response to growth of plant roots, plant growth and understory vegetation restoration, through experimental field survey, monitoring and sample determination. In addition, based on the comprehensive analysis of soil moisture-vegetation- precipitation system, we can reveal the basic mechanism of plant-soil interaction caused by soil moisture change, which can provide scientific basis for improvement of low-efficiency AS in southern Jiangxi province as well as research of revealing the mechanism of degraded forest ecosystem that influenced by seasonal drought stress in South China.