异质景观条件下朱鹮再引入种群的繁殖扩散研究

Breeding dispersal, the movement from one breeding site to another, is one of the most important life-history traits of birds that caused by species’ adaptive utilization of resources or environmental interferences. It not only helps to expand the population distribution area, adjusts the age structure and genetic structure of the population, but also avoids inbreeding and species competition. Its evolutionary mechanism includes resource competition hypothesis, local mate competition hypothesis, and the inbreeding avoidance hypothesis. This study will adopt theories and methods of ethology, molecular biology and landscape ecology to analyze the breeding dispersal of reintroduced populations of Crested Ibis in Ningshan, Tongchuan, and Qianyang of Shaanxi Province. GPS tracking and bird banding will be used to quantify ibises’ dispersal distances and directions, and microsatellite technique will be used to analyze genetic diversity, inbreeding index, and inter-individual sibship. Spatial-temporal dynamics of habitat will be linked to the process of breeding dispersal to analyze the effects of habitat heterogeneity on individual’s fitness as well as the mechanism of adaption under different environmental pressure. In addition, a habitat suitability model will be established to select and evaluate potential release site for reintroduction campaign of the Crested Ibises.

繁殖扩散是由于某种干扰因素或资源的合理利用造成的繁殖季节之间成体在繁殖地之间的移动，是有机体最重要的生活史特征之一。它不仅有助于扩大种群分布区、调整种群年龄结构和遗传结构，而且还避免了近交衰退和种类竞争。其进化机制包括资源竞争假说、局部配偶竞争假说和近亲繁殖避免假说。本研究采用行为学、分子生物学和景观生态学的方法对陕西宁陕、铜川耀州和宝鸡千阳三个朱鹮再引入种群扩散生物学进行系统研究，利用GPS卫星跟踪器和环志标识探讨朱鹮的扩散距离、方向和产生扩散的原因如年龄、性别、繁殖成功率等，探讨扩散过程因景观异质性变化导致的栖息地适合度变化。利用微卫星分子标记分析不同再引入种群的遗传多样性、近交指数和个体间亲缘关系。最终阐释朱鹮再引入种群繁殖扩散模式及进化机制；通过朱鹮再引入种群释放地景观模型的建立为朱鹮再引入项目释放地选择以及种群维持提供科学依据。

繁殖扩散是由于某种干扰因素或资源的合理利用造成的繁殖季节之间成体在繁殖地之间的移动，是有机体最重要的生活史特征之一。它不仅有助于扩大种群分布区、调整种群年龄结构和遗传结构，而且还避免了近交衰退和种类竞争。其进化机制包括资源竞争假说、局部配偶竞争假说和近亲繁殖避免假说。研究内容包括扩散行为及扩散过程、扩散模式及其影响因素、再引入种群的遗传多样性、近交指数和个体间亲缘关系。研究结果表明，繁殖扩散不仅贯穿于朱鹮繁殖个体生活史周期的全过程，而且与野生种群相比，无论是扩散频率还是扩散距离均呈现偏雌性扩散；微卫星分子标记研究表明，朱鹮种群呈现整体的低水平的遗传多样性，各种群之间尚未形成显著的遗传分化格局且存在一定程度的近亲繁殖。最后通过构建朱鹮再引入种群释放地景观模型为朱鹮再引入释放地的选择以及种群维持提供科学依据。