广西白头叶猴与黑叶猴生态位需求的比较研究

In natural conditions each species has a unique ecological niche as a response to the habitat in which it live. Generally, the more closely related species share more common in morphological and physiological characters than those with less related, and the ecological niche two species occupy also have the similar trend; there is no completely niche overlap between two species. White-headed langur (Trachypithecus leucocephalus) and Fran?ois' langur (T. francoisi) are closely related rare and threatened primate species. White-headed langur is endemic to Guangxi, China; Fran?ois' langur only survives in southwest China and north Vietnam. Both of them are endemic to limestone forest ecosystem. Zuojinag River, together with its upstream, Mingjiang River forms the distinct boundary of their habitats.Their classification status is still disputable. Understanding their niche requirement and similarity in similar but allopatric habitat is interesting. To date no synchronous study by same method has been conducted, thus no comparable niche requirement comparison data between white-headed langur and Fran?ois' langur are available. In this proposal we will adopt niche theory and methodology to synchronously and systemically study the niche requirement of white-headed langur and Fran?ois' langur via the same methodology. The study includes: (1) habitat characters of with-headed langur and Fran?ois' langur; (2) plant phenology of food species, especially the key food species; (3) food and spatial niche breadth and its seasonal variation; (4) niche similarity between white-headed langur and Fran?ois' langur; (5) their food quality indicated by available nitrogen (Avail N). Basing on the study of their niche requirements and their niche similarity, we aim to reveal their specific adaptive strategies to limestone environment and their sensibility to the environment change; we will also provide valuable behavioral information for further clarity of their classification status, as well as for habitat and population conservation of the two langurs.

自然状态下每一个物种都有自己独特的生态位以适应自己所处的环境，亲缘关系越近，结构和生理越相似，其生态位越近，没有哪两个物种生态位完全相同。白头叶猴与黑叶猴是分类地位一直存有争议的近缘珍稀灵长类动物，它们均为喀斯特森林生态系统所特有，其生活环境相似；左江及其上游明江是现生白头叶猴与黑叶猴的天然界线。本研究采用生态位相关的方法和思路，拟在相同的时间内利用相同的方法对左江两岸白头叶猴与黑叶猴生境的特征、物候变化规律、营养生态位和空间生态位的宽度及其季节性变化作比较研究，分析两者生态位需求、相似性及其变化规律，探讨它们适应喀斯特特殊环境的能力及方式。本研究将为今后进一步探讨白头叶猴与黑叶猴的分类地位及其特殊的分布格局提供行为学的数据资料，也为今后它们的生境和种群保护提供重要的参考依据。

白头叶猴仅分布于广西，黑叶猴仅分布于中国西南部和越南北部，它们的亲缘关系非常近，同属北热带喀斯特森林生态系统的珍稀灵长类动物，左江及其上游的明江是它们天然的分布界线。这两种猴形态大小相似，彼此之间的分类地位一直存在争议。因此，从比较它们生态位相似性的角度研究其适应方式，在这两种叶猴的分类中有重要的参考意义。研究表明，白头叶猴与黑叶猴的家域内植物种类分别是112种和195种，其中共有植物种数为58种，Jaccard相似性指数为0.23。白头叶猴与黑叶猴栖息地中食物物候动态变化的模式相似。白头叶猴与黑叶猴食物选择的策略都是选择地利用栖息地中植物，在主要食物种类中，植物生态位宽度与取食的时间呈显著的正相关（p<0.05），选择生态位较宽的植物种类为主要食物，食物种类的相似指数（J）为0.52，远高于栖息地植物种类的相似指数。保证有充足的食物来源；白头叶猴与黑叶猴的Shanon-Weaner食物生态位宽度指数（B）分别是4.02和3.71，白头叶猴与黑叶猴的食物部位组成极其相似（树叶：67.4% VS 67.7%；果实：13.0% VS 17.9%；花：6.7% VS 8.0%；种子：2.7% VS 1.2%），Renkonen百分比相似性系数（PS）平均值高达0.73。在空间生态的需求方面，两种叶猴在山体的利用上，其Shanon-Weaner空间生态位宽度指数（B）非常接近（1.74 Vs 1.66），而在树层的利用方面，白头叶猴的生态位宽度（B）比黑叶猴宽（1.34 Vs 1.10），两者的生态位相似性指数（PS）在0.76-0.94之间变化。食物营养成分分析表明，在有单宁阻剂聚乙二醇的条件下，食物中测定的蛋白含量更高，证实食物次生化学物质单宁物质对食物中的可利用性氮有影响。总之，虽然白头叶猴与黑叶猴栖息地中植物种类的相似指数小，但取食种类的相似性指数却非常高；另外，相对于其他已经开展过研究的灵长类，白头叶猴与黑叶猴在食物生态位和空间生态位相似程度都非常高。因此，基于它们对喀斯特环境相同的适应策略，结合它们相似的身体大小和生理结构，可以推测它们可能有相似的进化历程。