荒漠生态修复区风蚀过程及天然河岸林防风阻沙效应研究

Sandstorm disasters in northwest China has become increasingly serious, it not only affect the production of local life, and also pose threat to the national ecological environment. Considering the difficulty of implementing plantation for large area in extreme desert region, it is essential to conduct research regarding Assessment of wind and sand shelter mechanism and its benefit is a main scientific problem to be solved under current ecological restoration process. This project selects the Tarim River Basin downstream natural desert riparian forest vegetation as research object, based on the principles of ecology, environmental science, remote sensing and geographic information science disciplines, to combine To combine sand dynamics classic wind erosion model (IWEMS) with the field positioning observation wind erosion model (IWEMS), with the field positioning observation, GIS based spatial anlysis, and laboratory analysis processes, Analyze the sandstorm occurrence mechanism, wind erosion process in-depth of the natural vegetation in arid areas: (1) establish a model of quantitative relationship between sand transport flux (Q) and vegetation paramter, determine the best wind effect vegetation coverage (effective coverage) threshold;(2) clear the interactions between Aeolian processes with artificial water conveyance, groundwater levels, soil moisture and riparian forest vegetation growth;(3) Estimate the value of ecosystem services of natural vegetation and compare costs with the artificial sand control measures; Results of this project provide scientific support and decion making for the eco-environmental management, sustainable socio-economic development.

我国西北地区日趋严重的风沙灾害，不仅影响着当地生活生产，对全国生态环境产生威胁。对不易开展大面积人工造林的极端干旱区而言，揭示天然河岸林防风阻沙机理与效益评估是生态修复与治理过程中亟待解决的科学问题。本项目以塔里木河下游荒漠河岸林为研究对象，依托防护林学、生态学、遥感和地理信息技术及地统计学理论和方法，结合风沙动力学经典风蚀模型（IWEMS），借助野外定位观测、GIS空间分析、室内理化分析和模拟手段，对荒漠生态修复区的风蚀过程、天然河岸林防风阻沙机理和效能进行定量研究：1）揭示区域风蚀过程及其与人工输水、地下水位、土壤理化特性、植被长势的相互作用机制；2）构建风蚀输沙率（Q）与植被参数的定量关系模型，确定最佳防风效率的植被群落结构与覆盖率阈值；3）估算天然植被防风阻沙生态服务价值并与人工治沙措施（草方格铺设）成本进行对比。项目成果为区域生态环境治理、社会经济可持续发展提供决策依据和科学支撑

塔里木河下游沙尘天气频发、自然条件恶劣，对人畜健康、生产生活以及交通安全运营造成严重威胁。目前该地区主要采取人工草方格来防风阻沙并保障公路的畅通。然而，这种措施成本巨大，需反复施工。因此，依靠塔河下游胡杨（Populus euphratica Oliv.）、柽柳（Tamarix sp.）等天然荒漠河岸林的生态服务功能（防风固沙能力）来维护G218国道的生态安全是保持区域可持续发展的必要途径。天然植被防风阻沙效应的定量描述与评估是在区域生态修复与治理过程中亟待解决的科学问题。本项目从塔里木河下游日益严重的土壤风蚀问题出发，定量研究输水修复区天然荒漠河岸林的防风固沙能力与生态服务价值。通过野外定点观测（利用BSNE多通道集沙仪、Watchdog自动气象站、LI-6400光合仪、DEM6便携式风速仪、YGY-QXY手持式气象站、自然风沙收集皿、热脉冲茎流仪、LI-3000A叶面积测定仪、SC-1叶片稳态气孔计、测树仪等），室内测试分析（TAS-990分光光度计、Microtrac S3500激光粒度仪、LEO1430VP高精度电子显微镜、高精度电子天平）等措施获取野外数据，并完成基础研究分析工作。同时，以植被、地下水、气象要素长期定位监测数据为支撑，实地观测与风沙动力学经典风蚀模型IWEMS（Integrated Wind Erosion Modeling System）相结合，以风应力分解理论为基础，借助GIS统计与空间分析功能，对研究区10 km2样地内的风蚀侵蚀力、可蚀性因素以及天然河岸林植被防风阻沙效应进行了定量描述与模拟。一改以往仅集中于农田和人工防风林对风蚀过程影响的研究，而转向于极端干旱区内陆河流域天然荒漠植被防风效应的研究。项目成果不仅为当地生态环境建设、社会经济可持续发展提供决策依据，而且为我国西北干旱区乃至中亚内陆河流域开展的相关研究提供基础与借鉴。项目执行期间，已发表学术论文29篇（其中SCI论文12篇），组织召开国际学术会议1次；培养了博士后1名、博士生1名、硕士研究生3名；依托此项目，项目团队获批了NSFC-新疆联合基金项目一项（U1703102）、NSFC青年基金项目一项（31700386），一人获批中组部第十三批“青年千人”计划资助(2018-2020)。