碩士 / 國立中興大學 / 園藝學系所 / 100 / Abstract
The purpose of this study was to investigate typhoon effects on coastal windbreaks and bird diversity. This study focused on the coastal windbreaks located in Mailiao Township, Yunlin County and the three successive super typhoons that have hit Taiwan in 2005 including Typhoon Haitang from 16 to 20 July, Typhoon Talim from 30 August to 1 September and Typhoon Longwang from 30 September to 3 October. The change of windbreaks obtained from satellite image data and the formula for calculating bird diversity on environmental factors built from bird survey and multiple regression analysis were used to evaluate typhoon impacts on windbreaks and bird diversity, as well as the benefit to bird diversity from self-recovery process of windbreaks.
Results and discussion
The three successive typhoon events caused a continuous decline in the normalized difference vegetation index (NDVI) value of the coastal windbreaks, which indicated that the typhoon events had caused cumulative effects on coastal windbreaks. Further analysis of the cumulative effects on windbreaks with various widths showed that the narrower width of the windbreak, the stronger cumulative effects caused by the typhoons. In addition, the windward sides of windbreaks were the mostly affected followed by the leeward sides.
Five-year monitoring the NDVI value after the coastal windbreaks suffered from cumulative effects of the three typhoons showed a year-by-year gradual recovery. The windbreaks growth changing from initially damaged to gradually recovered then stabilized was consistent with the post-disturbance self-recovery process of landscape patches described in landscape ecology.
The Bird species and habitat relationship model was built from multiple regression analysis by using bird survey and field data from 2010 to 2011. Collected data revealed Pycnonotus sinensis was the dominant bird species in windbreaks and the analysis results showed that the increase in size of the well-conserved windbreaks area with better vegetation (NDVI value > 0.3) and the grassland area, and the increased temporal land mosaic of the grassland and study site favored an increase in the number of Pycnonotus sinensis. Data also revealed Streptopelia tranquebarica was the dominant species in the border area of windbreaks and the analysis results showed the number of Streptopelia tranquebarica grew as the size of farmland and its border area increased.
Backward extrapolation based on the relationship between bird species and their habitat in 2010 and 2011 was applied to investigate whether the resulting effects on windbreaks and the change of surrounding environment caused by the three typhoons had an influence on bird diversity and also the self-recovery process of the windbreaks. Our results showed that the windbreaks and the surrounding environment were affected by the three typhoons as well as the bird diversity decreased significantly; and the following recovery of windbreaks helped to increase bird diversity. The backward extrapolation results showed that the number of the dominant bird species in windbreaks and the border area (Pycnonotus sinensis and Streptopelia tranquebarica respectively) retuned to pre-typhoon level three years after the typhoon events (3 December 2008).
| Identifer | oai:union.ndltd.org:TW/100NCHU5378035 |
| Date | January 2012 |
| Creators | Yi-ru Chen, 陳怡茹 |
| Contributors | Chen-Fa Wu, 吳振發 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 110 |
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