Summary: | 碩士 === 國立臺灣師範大學 === 生命科學研究所 === 94 === Abstract
Ecologists are interesting to know how sympatric species can coexist to decrease interspecific competition. Because of having high specie and habitat diversity in Taiwan, it is appropriate to investigate about resource partitioning among species in a community. This study was conducted from April 2004 to August 2005, in Wu-too-ku stream of Taipei County .The main purpose of this research was to investigate the resource partitioning among sympatric frogs in a stream by using the index of niche breadth and niche overlap. Meanwhile we also explored the effects of human disturbance in resources utilization of Buergeria robustus in Wu-too-ku stream.
A total of 7 species were recorded from study site, Rana adenopleura, Rana kuhlii and Chirixalus idiootocus, were present only in small numbers. Their data were not analyzed. The major food items of Buergeria robustus and Rana latouchi were Lepidoptera larvae, Chilognatha for Bufo bankorensis, Blattodea for Rana swinhoana, calculated by the IRI index. Indexes of niche breadth indicated that the temporal (0.502), habitat (0.403), and diet (0.418) breadth of Rana latouchi were the widest among 4 species. Indexes of niche overlap indicated that the highest niche overlap was seen between Bufo bankorensis and Rana latouchi in temporal aspect (0.778), Buergeria robustus and Rana swinhoana with the greatest niche overlap in habitat aspect (0.854), and Buergeria robustus and Rana Rana latouchi with the greatest niche overlap in diet aspect (0.779).Results from our study suggests that sympatric species reduce interspecific competition by shifting in niche overlap in various aspects.
The component of rocks and difference in vegetation along riparian zones were considered the main reasons which decrease on amphibian abundance in human disturbance area. The density of vegetation affected the components of diet on Buergeria robustus. These findings suggest that difference in feeding habitats is the main mechanism to decrease the interspecific competition among sympatric frog species in a stream. It seems that human disturbance may provide some benefits for certain species of frogs.
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