大型食草动物的聚群规则:印度西部热带干旱森林中有蹄类动物局域和区域尺度的多样性格局

竞争能够塑造自然群落并由其给出可用备择模型检验的一般性聚集规则。关于多种动物集合的竞争结构证据至今还非常少见,我们给出了一个备择模型分析用于检验印度西部热带干旱森林中当地5种大型食草类动物(花鹿Axisaxis,印度大蓝羚Boselaphustragocamelus,水鹿Cervusunicolor,印度瞪羚Gazellabennetti,野猪Susscrofa)是否符合一般性集合规则。使用蒙特卡罗模拟分析了动物的生态位重叠和身体大小比率的类似性,结果表明当地这些种的集合不是竞争结构决定的,其内部阶元结构处于亚最适种丰富度。另外2种有蹄类(印度黑羚Antilopecervicapra,四角羚羊Tetracerusquadricornis)属于地域性种库的组成部分,但缺失于这种集合;身体大小组合在地域性物种集合中不是随机的,然而在当地集合中能够通过随机性机会获得。对于观察到的类型,我们认为由于灭绝留下的统计学空缺似乎最能解释现存集合。由于天敌(大型食肉类)能够减少猎物物种的种间竞争,使得这种无规则生态位配置具有成立的可能性。由于对四角羚羊(T.quadricornis)的生物学和保护现状知之甚少,未将该种包括在该聚集中。我认为对这类较少被人类了解的物种其保护问题被忽视了,今后获得这些稀少的地方特有物种的生态学资料是一项紧急课题.

Assembly rules in large herbivores: a null model analysis of local and regional diversity patterns of ungulates in dry tropical forests of western India

Competition can shape natural communities and give rise to general assembly rules that can be tested with null models. Yet, evidence for competitive structure is scarce from many animal assemblages. A null model analysis is done to test whether a local large herbivore assemblage of five ungulates ( Axis axis, Boselaphus tragocamelus, Cervus unicolor,Gazella bennetti and Sus scrofa ) in dry tropical forests of western India shows general assembly rules. Using Monte Carlo simulations, niche overlap and body size ratios are analysed in terms of limiting similarity. Results from niche overlap suggest the local assemblage is not competitively structured and has sub-optimal species richness with internal guild structuring. Two other ungulates are part of the regional species pool (Antilope cervicapra, and Tetracerus quadricornis ), but are absent from this assemblage. Body size relationships show that size-ratios are non-random in the regional assemblage;extant assemblage seems the most plausible explanation for the observed patterns. Since predators (large carnivores) can potentially reduce competition between prey species; this irregular niche-apportionment is possibly maintained. The absence of T. quadricornis from this assemblage raise concerns since very little is known about its biology, including its conservation status. An urgent need for generating more ecological information on this rare and endemic antelope is perceived since it appears that conservation concerns of such lesser-known species have gone unnoticed Acta Zoologica Sinica 52 (4): 634- 640, 2006].