碩士 / 國立臺灣大學 / 森林環境暨資源學研究所 / 101 / Natural forests have been diminishing rapidly worldwide, often replacing by monocultural plantations, which take about 20% of the forested areas of Taiwan. Natural forests make up the biggest proportion of forests of Taiwan, but more than half of them are secondary forests. Usually, people consider that secondary forests contain higher biodiversity than plantations. Nevertheless, there has been a lack of concrete evidence for this assumption and few studies have been conducted in Taiwan to examine this assumption. I compared birds, a taxonomically diverse group, of plantations and secondary forests in the low-elevation areas of Northern Taiwan. Twelve sets of paired sampling stations were established from neighboring plantations and secondary forests that have same development time and environmental condition. I used circular-plot method and direct focal observations of foraging behaviors to investigate the bird density, species richness, habitat selection, and resource utilization in the forests. The 45 bird species showed non-significant differences in population densities between plantations and secondary forests, except that Muller’s Barbet (Megalaima oorti), Grey-chinned Minivet (Pericrocotus solaris), and Varied Tit (Parus varius) had significantly higher densities in secondary forests. The 38 bird species were grouped into 10 ecological guilds based on their resource utilization patterns of habitats. The guild density of stations did not differ between plantations and secondary forests, excepting canopy insectivores and hawk insectivores. Similar forest foliage structure and coverage of understory layers may be the key reasons that the bird communities were similar between plantations and secondary forests. Although some habitat variables significantly differed between plantations and secondary forests, the differences in habitat structure might not be enough to significantly affect the composition of bird communities. Besides, birds might have weak discrimination in selecting these habitats; mosaic structure of plantations and secondary forests might increase the avian diversity in plantations. I conclude that, with appropriate silvicultural practices that create more heterogeneous floristic composition and vertical foliage structure, plantations can achieve greater contribution in conserving biodiversity.
| Identifer | oai:union.ndltd.org:TW/101NTU05359019 |
| Date | January 2013 |
| Creators | Wei-Jen Cheng, 鄭惟仁 |
| Contributors | 丁宗蘇 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 80 |
Page generated in 0.0143 seconds