林窗干扰对胡杨荒漠河岸林更新与演替的影响

Canopy gap is a common type of small-scale disturbances in the forests. As a driving force for natural regeneration and succession of forests, forest gap disturbances have an effect on plant invasion, seed germination, seedling settlement, and development of young tree species, which contributes to the healthy development and sustainable management of forest ecosystems. The project would build on the long-term terrestrial investigation and research results of the former research projects (NSFC: 30760050, 31360200) and new research ideas to target the gap disturbance of desert riparian forests along the middle and lower reaches of the Tarim River as a research objective, based on forest ecology, geo-statistics, remote sensing and GIS and other disciplines, combined with field observations, UAV LiDAR and mathematical model simulations, quantifies the spatial and temporal gap distribution patterns of Populus euphratica Oliv. under different hydrological conditions (surface runoff, groundwater, and artificial water transfer); Analyses the influence of micro-environment (water, soil and climate) on the development of seedlings; Predicts the place and occurrence time and turnover rate of riparian forest gaps, and evaluates the response of vegetation regeneration and succession to disturbance of Populus euphratica forest gap under different water stress. The research results would be helpful for understanding the rule of self-regeneration and succession of desert riparian forests in the Tarim River Basin, and provide scientific support for the sustainable management of natural desert riparian forests in arid regions.

林窗是森林生态系统中常见的小尺度干扰类型，是森林生态系统自然更新与演替的驱动力，对植物侵入、种子萌发、幼苗定居与幼龄树种生长发育具有促进作用，有助于森林生态系统的健康发展与可持续管理。本项目依托申请团队多年的研究成果（NSFC:30760050,31360200）和发现的新问题、新思路，以塔里木河流域荒漠河岸林林窗干扰为研究对象，基于森林生态学、地统计学、地信与遥感等学科理论与方法，结合野外观测、机载LiDAR和模型模拟等研究手段，对不同水文（地表水、地下水、人工调水）条件下胡杨林林窗时空分布格局进行定量研究；探明林窗微环境（水、土、气）对幼苗发生发育的影响；预测河岸林林窗发生地与发生时间及其周转率，评价不同水分胁迫下植被更新与演替对胡杨林林窗干扰的响应。研究成果有助于了解塔里木河流域荒漠河岸林自我更新与演替规律，为干旱区荒漠河岸林资源保育与可持续管理提供科学支撑。

林窗是森林生态系统中常见的小尺度干扰类型，是其自然更新与演替的驱动力，对植物入侵、种子萌发、幼苗定居与幼龄树种生长发育有促进作用，有助于森林生态系统的可持续发展。本项目借助课题组历年采集的河岸林植被数据库，利用RigelVZ-1000地面激光雷达/TLS、中海达iRTK2智能基站、大疆PRO4无人机航拍系统、Arbotom应力波树木断层成像仪、TDP热脉冲茎流仪、LI-3000A叶面积仪、自动气象站、地下水检测仪、土壤湿度仪、测高仪等仪器设备，对塔里木河流域不同水文条件下的胡杨林林窗特征参数及其时空差异进行监测研究，力求解析胡杨林林窗形成及其对荒漠河岸林更新与演替的影响机制。在塔里木河上、中、下游布设样地，将传统小尺度地面监测、激光雷达扫描反演、无人机低空拍摄和高分遥感影像解译相结合，对胡杨生长态势指标(个体与林分结构参数、植被覆盖率、叶面积指数、地上生物量、枝系构型特征、林窗空间分布特征、种群空间分布格局等)进行信息提取和统计分析，探索胡杨树干腐朽及死亡机制；探明林窗微环境(水、土、气)对幼苗发生发育的影响，预测林窗发生地与发生时间及其周转率，评价不同水分胁迫下植被更新与演替对林窗干扰的响应。研究成果有助于阐明胡杨林自我更新与演替规律，为干旱区荒漠河岸林资源保育与可持续管理提供科学支撑。.依托本项目，在国内外核心期刊上共发表学术论文13篇(含高水平SCI期刊论文6篇)，举办学术会议3次，作学术报告/海报展示20余次，参加国内外重要学术会议30余人次；培养博士生4名，硕士生6名，本科生4名，完成大学生创新训练SRT项目1项；新获批NSFC项目1项，科技部第三次新疆综合科学考察课题1项，新疆大学优秀博士生创新项目1项；派出4名博士生赴德国研修一年，为培养具有国际视野的创新型人才提供平台。本项目圆满完成了各项任务，达到预期目标，研究成果将为塔里木河流域生态文明建设、区域高质量发展提供决策依据，且为中亚干旱区流域综合治理提供借鉴参考。