纵向山脉对潜叶昆虫多样性及群落组成的影响机制

The longitudinal mountains refer to the mountains generally extending at a north - south direction. Significant water differentiation is often found between the windward slopes and leeward slopes, leading to distinct differences in the composition and distribution of animal and plant species. Leafminers, including Lepidoptera, Coleoptera, Diptera and Hymenoptera, are a group of insects which larvae live and feed inside the leaf tissue of plants, with the epidermis or the outer wall remaining intact. With such characteristics as habitat specific, range restricted, and limited mobility, leaf-mining species can be used as model organisms to study inter-specific relationship, environmental adaptability and coevolution. At present, there are quite a few researches on the leaf-mining insects richness and the corresponding latitudinal gradient patterns, but the studies on the effect of longitudinal mountains on the diversity and community composition of leafminers are still scanty.. In this project proposal, Wuyi Mountains are chosen as a representative of longitudinal mountains, to systematically study the differences among the diversity, community composition and community phylogeny of leafminers in different slope (windward slope vs leeward slope), to analyze the relationship between different habitat factors and leafminer diversity, to discover the differences in the geographical diffusion modes and response mechanisms of different leafminer groups based on phylogeographic analyses, to sort out the effects and the corresponding mechanisms of important biogeographic factors on the diversity and distribution of leafminer species, thus to improve our understanding on species diversification theory.

纵向山脉是指大致为南北走向的山脉。纵向山脉的迎风坡与背风坡常常存在显著的水分分异，进而导致动、植物的种类组成及分布等表现出明显的差异。潜叶昆虫是以幼虫潜食叶肉或表皮组织的一类昆虫，包含鳞翅目、鞘翅目、双翅目和膜翅目。其一般具有栖息地特异性、范围限制性及有限的移动性等特征，因此可作为一类研究种间关系、环境适应性和协同进化的模式生物。目前，关于潜叶昆虫物种丰富度及纬度梯度分布格局的研究不少，但有关纵向山脉影响潜叶昆虫多样性及其群落组成的研究稀少。本申请项目以武夷山脉为纵向山脉代表，系统研究我国东部亚热带常绿阔叶林纵向山脉不同坡向的潜叶昆虫多样性、群落组成和群落谱系差异，分析不同生境因子与潜叶昆虫多样性之间的关系；通过谱系地理分析，探讨不同潜叶昆虫类群对纵向山脉的地理扩散模式及响应机制差异；筛选影响潜叶昆虫多样性及分布的重要生物地理因子及其作用机制，深化对纵向山脉物种多样化理论的认识。

纵向山脉是指山脉延伸方向大致为南北走向的山脉，其迎风坡/背风坡存在典型的水分分异，进而导致动、植物的种类组成及分布等表现出明显的差异。本研究以武夷山脉为纵向山脉代表，系统研究了中国东部中亚热带纵向山脉不同坡向的潜叶昆虫多样性及群落组成差异，研究结果表明：.1）武夷山脉潜叶昆虫多样性及群落组成极其丰富。本研究采集、饲养、鉴定了4目（双翅目、膜翅目、鞘翅目及鳞翅目）15科200余种潜叶昆虫，发现了40余新种及20余种中国新纪录属、种。.2）武夷山脉迎风坡（东坡）/背风坡（西坡）的潜叶昆虫在目、科级阶元上无差异，原因在于武夷山脉大部分山峰海拔没有达到2000米的降水临界高度，没有显著改变降水分布格局，导致坡向的作用明显弱化，对潜叶昆虫在目、科高级阶元的扩散和分布没有造成较大影响。.3）迎风坡（东坡）无论是在属（尤其是特有属、种）还是在种级阶元上，其数量显著高于背风坡（西坡），原因在于纵向山脉的小区域隔离容易导致物种分化，且斜坡在物种分化中起了重要影响，东坡迎风坡斜坡较多，具有多样性的微环境和微气候，因此具有较高的物种多样性及群落组成，而背风坡则相反；由于坡向造成的温度差异导致迎风坡潜叶昆虫物种的地理分布格局更倾向于亚热带-热带成分，而背风坡的分布格局则倾向于温带-亚热带成分。.4）纬度梯度对纵向山脉潜叶昆虫多样性及群落组成也造成一定影响，在属、种阶元及特有种上则呈现两头高（并且北段最高、南段次之）、中间低的趋势，特有属全部集中于北段迎风坡，其它则为0。原因在于武夷山脉由北向南延伸无间隔、地理距离较近及海拔逐渐降低密切相关，在北段物种数量高与其小区域隔离、斜坡众多密切相关，在南段与其位于南岭与武夷山脉的交汇处有一定关系。研究结果深化了对纵向山脉物种多样性机理的认识。