鄱阳湖非繁殖期水鸟多样性对水位的响应及优势水鸟生态位分化研究

Poyang Lake is the largest freshwater lake in China. It receives the water from Ganjiang River, Fuhe River, Xiushui River, Raohe River, Xinjiang River. Poyang Lake provides good resting and foraging habitats for tens of thousands wintering birds every year. Howevr, the researches of birds in Poyang Lake only focus on monitoring of the distribution and number. Some ecological theories on waterbirds in Poyang Lake are not clear. Based on some theories such as niche and guild, wintering waterbird diversity, niche separation, their response to water level will be studied in four regions (Poyanghu National Nature Reserve, Nanjishan National Nature Reserve, Duchang Migratory bird Nature Reserve, Poyang Lake in Poyang county) in Poyang Lake, using point count, instantaneous scan sampling in this project. ① From diversity level, waterbird distribution rule, migration dynamics and their response to water level will be analyzed through comparision of temporal and spatial varivtion of bird diversity in different regions of Poyang Lake during Non-breeding period.②From population level, population size, group size, behaviors of four representative rare waterbirds such as Grus leucogeranus, Ciconia boyciana, Platalea leucorodia, Cygnus columbianus will be studied. Wintering ecological requirement and ecological adaptation mechanism to water level changes will be understood after population size, group size, behaviors of these species are studied. ③Interspecific relationship, ecological coexisting mechanism of dominant waterbirds will be discussed by analysis of interspecific correlation, guild composition and niche. This project can solve some theoretical issues such as guild composition, ecological coexisting mechanism. This project can also provide scientific basis for bird diversity conservation and hydraulic project in Poyang Lake.

鄱阳湖是中国第一大淡水湖，为数十万候鸟提供良好的栖息场所。然而鄱阳湖鸟类研究仅局限于数量监测，对鸟类的生态学理论问题缺乏研究。本项目拟采用样点法、瞬时扫描法并结合生态位和物种集团等理论，对鄱阳湖4个区域（鄱阳湖国家级保护区、南矶山国家级保护区、都昌候鸟保护区和鄱阳县鄱阳湖湖区）的非繁殖期水鸟多样性与4种珍稀水鸟对水位的响应及优势水鸟生态位分化进行研究。①通过对比鄱阳湖不同区域水鸟多样性的时空变化，从多样性层面探讨越冬期水鸟分布规律、迁徙动态及与水位的关系；②通过4种代表珍稀水鸟种群大小、集群、行为与水位关系的研究，从种群角度探讨其生态需求、对水位变化的生态适应机制、及对水位的指示作用；③分析种间数量随时间变化的相关性、物种集团组成和生态位，揭示优势水鸟的种间关系、共存机制。本项目的实施可解决鄱阳湖水鸟的一些生态学理论问题，为水鸟多样性的保护提供依据，也为鄱阳湖水利枢纽工程的开展提供依据。

鄱阳湖是中国最大的淡水湖，国际重要湿地，每年有约50-60万水鸟在此越冬。鄱阳湖水鸟多样性已得到国内外学者的广泛关注，然而鄱阳湖鸟类研究主要集中在水鸟数量分布的报道，调查周期短，不能全面反映鄱阳湖水鸟多样性的时空动态。鄱阳湖水鸟的行为适应对策、对水位变化的响应和种间关系等理论问题的研究相对缺乏。本项目选择鄱阳湖国家级自然保护区、南矶湿地国家级自然保护区、东鄱阳湖国家湿地公园、都昌候鸟省级自然保护区等，开展以下研究工作：（1）鄱阳湖陆生鸟类与水鸟多样性及其对水位的响应：共记录陆生鸟类7目29科69种。其中国家Ⅱ级保护鸟类5种。记录水鸟65种，其中国家I级重点保护鸟类4种，包括东方白鹳Ciconia boyciana、黑鹳Ciconia nigra、白鹤Grus leucogeranus和白头鹤Grus monacha。豆雁Anser fabalis、小天鹅Cygnus columbianus和鸿雁Anser cygnoides是鄱阳湖的优势种。潜水取食的鸟类一般在越冬早期和后期较多，因为越冬中期的水位较低。鄱阳湖及其5个区域水鸟数量与水位表现出高度一致的趋势：水位越高，水鸟数量越少。水位与不同区域水鸟的数量分布主要呈负相关；（2）鄱阳湖珍稀水鸟对水位的响应及其行为适应对策：本项目对6种濒危水鸟的越冬行为、集群特征、年龄组成等越冬生态开展了大量的研究。其中鹤类和东方白鹳的分布区比较固定，每年均主要分布在某几个保护区或湖泊。小天鹅分布相对分散。行为方面，小天鹅和东方白鹳以取食和休息为主，鹤类则以取食和警戒为主。鄱阳湖鹤类集群均以家庭群为主，白鹤家庭群中2成2幼的比例较低。灰鹤Grus grus的幼体比例在14-25%，表明灰鹤种群有上升的趋势；（3）鄱阳湖优势水鸟生态位分化及种间关系：3种共存涉禽与2种共存游禽研究均表明，这些物种通过行为高峰期的错开以及生境利用的差异，达到减少中间竞争，达到共存。9种大中型涉禽有较为相似的资源偏好，潜在的竞争物种可通过空间、生境和时间差分化而共存；（4）鄱阳湖优势水鸟的种团划分：鄱阳湖的物种集团包含5类：浅水种团、浅水和草洲种团，草洲种团，深水种团，深水和浅水种团。