局部尺度的地景組成對台灣北海岸山村鳥類多樣性及鳥種組成之影響

Effects of the Local-Scale Landscape Composition on Bird Diversity and Species Composition in Mountain Villages of Northern Coastal Taiwan

傅淑瑋(Shu-Wei Fu) ； 王相華(Hsiang-Hua Wang) ； 蘇聲欣(Sheng-Hsin Su) ； 葛兆年(Chao-Nien Koh)

《台灣林業科學》 37卷4期 (2022/12) Pp. 309-335

https://doi.org/10.7075/TJFS.202212_37(4).0005

摘要

北海岸山村地區多樣鑲嵌的地景組成，提供人民生活所需的資源，同時也是低海拔野生動物棲息空間。規劃適宜的山村地景組成比例，將可兼顧資源利用與生物多樣性保育。為研究北海岸地區山村地景變數與鳥類多樣性的關係，2019～2021年間於新北市淡水、三芝、石門、金山與萬里區的鑲嵌地景設置不同森林－農田覆蓋比例的樣點進行調查，並從棲地偏好、食性與覓食層次等不同功能群加以探討。結果顯示，100與300 m尺度地景組成因子均顯著影響北海岸山村的鳥類多樣性及鳥種群聚組成，其中以森林覆蓋比例為關鍵因子。森林覆蓋比例較高的樣點雖然整體陸域鳥種數比較少，但森林棲息鳥種種類數較多，而隨著森林覆蓋比例的減少，偏好農田、灌草叢與廣域等棲地類型鳥種數，肉食、蟲食、穀食性的鳥種數，以及於多層次、灌叢、地表及空中覓食的鳥種數則逐漸增加。鳥種組成的分析結果亦呈現多數的森林棲息鳥種、冠層覓食鳥種、果食及蟲食性鳥種、蜜食性鳥種傾向出現於森林覆蓋比例較高的樣點。另外，特有種鳥種數隨森林覆蓋等級降低而減少。進一步計算在300 m尺度下森林棲息鳥種數隨森林覆蓋比例變化之門檻值，結果顯示當森林覆蓋比例低於49.9％時，鳥種數明顯開始減少。根據上述結果，北海岸地區山村鑲嵌地景建議維持五成以上的森林覆蓋比例，以維持對於森林棲地專一性高的鳥種多樣性，此項建議亦可能有助於維持當地特有鳥種的棲息環境。

關鍵字

鳥類 ； 物種多樣性 ； 物種組成 ； 山村 ； 地景組成

並列摘要

Diverse mosaic environments within mountain village landscapes in northern coastal Taiwan can simultaneously provide resources for human livelihood and support various habitats for wildlife at low elevations. To achieve both sustainable use of resources and biodiversity conservation, assessing and planning appropriate proportions of landscape composition in mountain villages is of critical importance. To explore relationships between landscape variables and avian biodiversity in mosaic landscapes of mountain villages, we conducted bird surveys in sample plots of different forest-agriculture landscape mosaics in the Tamsui, Sanzhi, Shimen, Jinshan, and Wanli Districts of New Taipei City in 2019~2021. Bird species were classified into different groups according to 3 functional categories (habitat preference, diet, and foraging stratum) and separately analyzed. Results showed that the 100- and 300-m-scale landscape composition variables significantly affected bird diversity and composition. Among them, forest cover was a key factor. Terrestrial total bird species richness decreased with higher forest cover, whereas the richness of forest bird species increased. In contrast, the richness of farmland, shrub and grassland, and general bird species, the richness of bird species belonging to foraging strata other than the canopy, and the richness of carnivorous, insectivorous, and granivorous bird species all gradually increased with decreasing forest cover. Analyses of bird species composition also showed that most forest species, canopystratum species, frugivorous/insectivorous species, and nectarivorous species occurred at sampling plots with higher forest cover. In addition, numbers of endemic species in landscapes decreased with decreasing forest cover. We estimated the threshold value of forest cover that may largely alter the species richness of forest birds and found that forest bird species richness significantly decreased when the forest cover was < 49.9% at the 300-m landscape scale. Therefore, we suggest that retaining > 50% of forest cover in mosaic landscapes in mountain villages of northern coastal Taiwan would help maintain bird diversity of forest specialists and might also support habitat conditions for local endemic species.

並列關鍵字

bird ； species diversity ； species composition ； mountain village ； landscape composition