The Relationship between Avian Community and Forest Landscapes in Guanwu, Tawain
|Keywords:||地景;海拔;地理資訊系統;鳥類群聚;生態同功群;人造針葉林;geographic information system;landscape;elevation;conifer plantation;bird community;guild||Issue Date:||2004||Abstract:||
Due to the long term forestry activities, the mid-elevation zone of mountain area in Taiwan is now dominated by mosaic landscapes composed of grasslands, plantations and natural forest of different serial conditions. However, researches in Taiwan scarcely take notion to bird communities inhabiting these mosaic environments. Thus, in order to seek for the relationship between mosaic forest landscape and bird community, an one year round bird survey in 8 different landscapes at Guanwu (Hsinchu, Taiwan) was conducted in 2003, and a vegetation map of these landscapes was created using remote sensing technology and geographic information system.
37 bird species were recorded in the whole year. According to canonical correspondence analysis (CCA)，when study site extends an elevation range larger than 450 meters, elevation is the most important factor affecting the composition of bird community; but when elevation range is less than 250 meters, landscape composition turns to be the primary affecting factor, landscape configuration and elevation is less important. The bird community of different landscapes changes immensely only when (1)elevation of landscape shifts more than 200 meters and when (2) the landscape is composed by >40% grassland or conifer plantations. Bird species richness decreases in high elevation and grassland landscapes, and landscape dominated by conifer plantation supports a bird community with several high elevation bird species that scarcely occurs in other landscapes. Comparing guild composition reveals a food resource view of the difference between each landscape: grassland landscape supports proportionally more shrub insectivores than other landscapes; conifer plantation landscape supports more ground feeders and also shrub insectivores; natural forest landscapes support bole insectivores that almost never inhabit conifer plantation nor grassland. In the other hand, tree feeders, which constitutes the major composition of bird communities doesn’t have a clear difference between each landscape. In conclusion, this research restates the importance of elevation to bird communities; and when elevation extent is small, bird communities will change notably when the proportion of grassland or conifer plantation in the landscape exceeds a certain threshold.
|Appears in Collections:||生態學與演化生物學研究所|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.