大熊猫(Ailuropoda melanoleuca)生境选择研究进展

Review of habitat selection in the Giant Panda (Ailuropoda melanoleuca)

在回顾大熊猫生境选择研究历史的基础上,总结了大熊猫生境选择的考察因子、研究方法,概括了大熊猫对对觅食条件、隐蔽条件和气候条件的选择机制,并探讨了大熊猫生境选择的灵活性及大熊猫和与其同域分布的动物种的共存机制。作者认为,野外调查误差大、研究尺度单一等是目前大熊猫生境选择研究中存在的主要问题,应用目前较流行的已被证明比较优良的资源选择函数法、DNA指纹技术、无线电遥测、红外线自动感应照相系统、GIS与遥感成像等先进技术,并融合景观生态学理论,从较大尺度空间来研究大熊猫的生境选择,应是今后的发展方向。

This paper is a literature review on the characteristics of giant panda （Ailuropoda melanoleuca ） habitat selection. Habitat selection has been one of the main focuses of ecological research of the giant panda. These data can be used for many purposes, such as releasing or reintroducing giant pandas to the wild, which has been made a priority and major part of giant panda conservation programmes. The main aim of this paper is to summarize the characteristics of giant pandas＇ habitat selection to provide reference to guide conservation action, especially the release of pandas into the wild. The environmental variables that have been studied and the methods used are summarized. Previous research noted some important biotic and abiotic factors such as forest canopy, slope of terrain, slope orientation, forest type, bamboo density, bamboo height, and bamboo basal diameter. For the methods used in prior studies, we compile the commonly used techniques in field studies and in statistical analyses. Herein, we refine the generalities in giant panda habitat and food selection. The optimal habitat for the giant panda is bamboo forest of moderate density on gentle slopes in mixed coniferous- broadleaved forests with medium canopy cover. The bamboo in these areas tends to grow relatively tall with thick stems. Conversely, habitats disturbed by human activities are strongly avoided by pandas. It is believed that giant pandas smartly ＂weigh＂ the benefits and costs when selecting appropriate habitats; maximizing the rate of energy intake may be the driving force of habitat selection. More specifically, A. melanoleuca seems to follow the Optimal Foraging Theory. We attribute the mechanism of habitat selection to their selection for food, shelter, and climatic conditions. Many of the activities and behaviours of A. melanoleuca are associated with the quantity and quality of edible bamboo. Forest canopy is one of the most important variables since it influences the distribution of precipitation and light, consequently affecting the growth of understory bamboo. Ailuropoda melanoleuca prefer mild climates, which results in a seasonal shift between different elevations and its preference for sun-facing exposure. The flexibility of habitat selection is also discussed. The characteristic of pandas＇ habitat selection is genetic, but in no sense invariable. On the contrary, selection varies to some extent according to the region （e. g. between different mountain areas）, season, and environmental variation （e. g. bamboo flowering）. This flexibility in habitat selection is generally considered a kind of adaptation to the changing environment. Giant pandas live sympatrically with red pandas, bamboo mice, and cattle, all of which eat bamboo. However, significant differences in their microhabitat structure exist, reducing competition and allowing coexistence. For example, each chooses bamboo of different sizes, indicating that they partition one or more habitat resources. It is recognized that microhabitat separation resulting from competition between species is the dominating force that allows giant pandas to live sympatrically with other bamboo-eating species. Additional areas of future research needed to completely understand the habitat selection of the giant panda are also discussed. We agree that future research should use a combination of technological approaches, including RSFs, DNA fingerprinting, radiotelemetry, auto-trigger camera traps, and GIS integrated with landscape ecology theory, to more accurately determine the process involved in A. melanoleuca habitat selection.