| Summary: | 碩士 === 靜宜大學 === 生態學系 === 100 === This study was to establish the relationships between the avian biodiversity, the bird community structure and the habitat factors on the low-altitude tableland in South West Da-Du Mountain and to understand the changes in bird community in various stages of fire on the grassland. The survey on bird community and habitat factors was conducted from January to September 2008. Three sets of habitats were chosen respectively in grassland, transit area and woods. A total of 36 sampling points were set up for bird density survey by point count, each having been stayed for ten minutes. The survey on avian biodiversity lasted for nine months, each covering 36 point-attempt. The survey results recorded 53 species in 31 families; in terms of species composition, 30 species in 19 families were recorded in each the woods and the transit area, and 20 species in 22 families in the grassland. Similarity index was high in the transit area situated between the woods and the grassland, and was not high in either the grassland or the woods. Total bird quantity and total density were both the highest in the woods, having significant differences from the other two types of habitats. Number of species was the highest and significant in the transit area. Shannon-Wiener diversity index and Shannon-Wiener evenness index were the highest in the transit area. When the 41 species were divided into 13 guilds, seven guilds differed significantly.
The habitat factors survey recorded 14 species of woody plants in 10 families. Out of the three habitats, some 22 facts were significant, while the relative herb layer foliage was not. The total density and evenness were reversely related to relative herb layer foliage to as significant extent and positively related to foliage closeness (herb layer, shrub layer, sub canopy, canopy, total foliage volume, and relative shrub layer), ground coverage, vegetation height (shrub layer and canopy), vegetation composition and biomass. And the Shannon-Wiener evenness index was positively related to foliage closeness (sub canopy, canopy, total foliage volume, and relative canopy layer), average canopy height, coefficient of variation of woody plant diameter at breast height, and tree quantity. Accordingly, it was revealed that total density and evenness were influenced by habitat factors, while the number of avian species and diversity index were neither related to habitat factors nor the main factor of the avian community.
The post-fire avian species eigenvalue became lower right after fire, either it be severe or light fire. After the severe fire, the bird community eigenvalue was the lowest, with the evenness index being the greatest at this time. In the habitat with light fire, the community eigenvalue dropped in the same month, but soon recovered in the following month. To conclude, despite the fire scales, both the eigenvalue in the two distinct habitats would drop. In terms of the post-fire plantation and avian species recovery speed, the eigenvalue would recover speedily in the post-fire period, particularly after the light fire, while in the habitat after the severe fire, it would recover slowly.
Keywords：Interference, fire, guild, bird community, habitat factor
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