水电开发影响下河岸带植被生境模拟研究

The eco-environment problems caused by hydroelectric development are a hot spot issue of society and highly concerned by scientists. To reduce the conflict between hydropower development and eco-environment system is an urgent requirement of harmonize implementation of hydropower development and environment protection, maintaining river ecosystem health, and regional sustainable development. Based on species protection, habitat suitability simulation method considers the habitat demanding of biology, and establishes the quantitative relationship between biology living state and reservoir operation mode. It has becoming the basic theory and method to build reservoir operation rule in order to considered both hydropower development and ecological system protection. Fish and vegetation are the two most important indicate biologies in river ecological system. Fish habitat suitability simulation model has been established under the supporting of National Natural Science Foundation of China (No. 50909006). This project aims to develop vegetation habitat suitability model to simulate the habitat suitability of riparian vegetation. Selecting key vegetation in studying area, main eco-factors will be analyzed, and vegetation habitat quality evaluation indeces system will be established. Based on the relationship between main eco-factors and vegetation living state, vegetation habitat suitability function will be developed. By coupling hydraulic model and vegetation habitat suitability function, vegetation habitat suitability model will be established. Then, vegetation habitat suitability under different reservoir operation scenes will be predicted by the model. As a result, security threshold value of protection population quantity and distribution of vegetation will be obtained.

水电开发引起的生态环境影响问题是当前科学研究和社会关注的焦点，也是实现流域水电开发与生态环境保护相协调、维系河流生态系统健康的迫切需要。基于物种保护的栖息地模拟方法考虑生物本身的需求，成为协调水电开发和河流生态系统保护，建立水库生态调度模式的可靠的理论与方法。鱼类和水生植物是河流生态系统中关键的生物物种，在青年基金项目“长江中下游鱼类栖息地模型研究”的支持下，申请人对鱼类栖息地模拟进行了较为深入的研究，开发了鱼类栖息地适宜度模型，并得到很好的应用。相关成果发表论文15篇，其中以第一作者发表SCI论文4篇；发表EI论文10篇，专著2部，参加国际会议4次。本研究拟在鱼类栖息地模拟的基础上，开发河岸带植被生境模拟模型。模拟不同水库调度情景下植被生境适宜度水平，提出保护植被种群数量与分布的水库调度安全阈值，进一步完善水库生态调度理论与方法体系。

生境的数量、质量对物种的“存在—缺失”、丰度有显著影响。水利工程建设、气候变化等导致物种适宜的栖息地面积减小、质量下降。目前，生境丧失已成为导致物种濒危灭绝的主要原因。生境适宜度评价根据目标物种所需的生境条件，选取关键的生境因子代表生境状态，并与物种的生境偏好相关联，评价生态环境条件对于该目标物种栖息的适宜程度。生境适宜度模型以非生物和生物变量为基础，预测物种的出现频率，加深对物种—生境关系的理解，将生境要求定量化。本项目以河岸带植被水杨柳为例，基于最大熵原理建立了生境适宜度模型，筛选出各个环境因子对于水杨柳生境适宜度的响应曲线，计算各环境因子对模型的贡献，并对三个历史时期（1950-1959、1975-1985、2000-2009）及两个未来气候变暖情景（RCP 2.6和RCP 8.5）下云南省水杨柳生境适宜度的分布情况进行模拟。研究结果显示水杨柳的最适宜生境分布在：距离最近的河流的垂直距离小于150 m，年均温 Bio1在25℃—27℃的范围内，温度季节变化方差 Bio4约为3.2℃，最干月降水量 Bio14约为20 mm，降水季节性变异系数 Bio15在60—65，以及最冷季度降水量 Bio19在112 mm—120 mm的范围内时。三个历史时期，南部适宜度高于北部，离河流越近适宜度越高，从1950—1959到2000—2009，气候影响下水杨柳生境适宜度逐渐提高。气候变暖对水杨柳生境适宜度的变化起正效应。然而建坝带来的河岸带地表水位和地下水位的变化、土地利用的变化等人类活动破坏了部分水杨柳的生境，造成种群数量减少。.研究成果共发表SCI论文11篇，中文论文1篇，获得实用新型专利3项，获得软件著作权2项，合作出版专著1部，国际会议大会报告6次。项目主持人在项目执行期间获得德国“洪堡学者”和中国教育部“青年长江学者”称号。