1990~2013年来洞庭湖区鸟类生物多样性热点区时空动态及变动机理

评估与确定生物多样性分布格局与热点区是建立保护区、制定生物保护决策的基础。洞庭湖地区位处长江中游，是我国重要的淡水湖泊湿地生态系统，为中国乃至亚洲较大的鸟类越冬地之一。以洞庭湖地区14种Ⅰ、Ⅱ级重点保护鸟类为指示物种，基于1990~2013年间的多期遥感影像，运用物种生境分布MAXENT模型，选取地形、水系、植被、气候及人类干扰等共35个影响因子，对其进行生境适宜性评价及生物多样性热点区的筛选与制图，并对热点区时空动态特征进行分析。结果表明：（1）鸟类生物多样性热点区的分布范围呈现出组团状特征，1990~2013年来，热点区面积呈下降趋势；（2）鸟类栖息生境景观格局总体上趋于破碎，生境形状向简单且扁平化形态转变，生境格局呈复杂化；（3）经济与社会发展因素对研究区的鸟类生物多样性热点区变化影响显著，而自然因素产生的影响不明显。研究结果在制定区域生物多样性保护规划方案中可体现较好应用价值。

SPATIO-TEMPORAL DYNAMICS AND MECHANISM OF AVIAN BIODIVERSITY #br# HOTSPOTS IN DONGTING LAKE REGION DURING 1990-2013

Assessment and investigation of biodiversity distribution (and/or hotspots) are the foundations of conservation area establishment and biological protection decisions. Dongting Lake area located in the middle reaches of the Yangtze River, is an important wetland ecosystem in China. It is one of the major wintering habitats for the migrant birds of China or Asia. This study focused on the spatiotemporal characteristics of fourteen protected bird species (class I and II) in Dongting Lake area, analyzed total 35 environmental factors, such as topography, water types, vegetation, climate, human activities influences, etc. The Maxent model was used to access those birds habitats suitability. The results showed: (1) These bird biodiversity distributions were featured as group, and the bird habitat hotspot areas were decreasing from 1990 to 2013; (2) The landscape pattern of the bird biodiversity hotspots tended to break down, and these habitat shapes were becoming simple and flat; but the habitat patterns were turning to complex; (3) Economic and social developments showed significant influence on birds biodiversity hotspots of this region, but those naturally environmental factors didn't. These results may be useful for regional biodiversity conservation.