Terrestrial bird species richness in urban riparian zone: hypotheses of area, isolation, productivity, heterogeneity and disturbance.

對於都市鳥類群聚研究，過去著重於探討都市化對於鳥種多樣性的影響。如何更積極地維持並提高都市的鳥種多樣性，已成為都市生態學的主要議題。都市河濱地區擁有大面積且連續的綠地，並具有連結山區與都市綠地的生態廊道功能。不定期的洪氾擾動，更形成了多種類型棲地與較高的植被覆蓋度，提供都市鳥類潛在可能利用資源與棲息場所。但鄰近都市的特性，也使得人為干擾相對較高。儘管如此，目前對於都市河濱鳥類群聚受那些環境因子所影響，目前還不清楚。 若要有效管理河濱地區，並提出有效且適當的經營策略，首先必須釐清各環境因子對河濱的鳥種多樣性的影響與重要性階層。因此，本研究目的為：以地景的角度，將河濱地區的環境變數區分為在地（local）與外在（regional）因素，針對河濱的陸域繁殖鳥種數與棲地同功群，檢測島嶼生物學中的面積效應與隔離度、初級生產力、棲地異質性以及人為干擾假說的關係及其影響程度。 研究地區位於臺北市的河濱地區，於2013年3月到6月間，每月以定點調查法記錄半徑50公尺圓內的鳥類物種與數量，共調查72個樣點。環境因子選取河濱內部河岸寬度、植生指數、地景異質性指數、樹種多樣性、人工建物面積以及與山區距離。統計分析以廣義線性模型與AIC數值挑選最佳模式，並以Akaike weight排序環境因子的相對重要性階層。 研究結果顯示河濱地區的陸域繁殖鳥類物種數同時受到內在因素與外在因素的影響。離山區距離與樹種多樣性為影響陸域繁殖鳥類物種數的主要因子，其效應分別為負向與正向。不同棲地同功群的反應則不一致，棲地專一性鳥種偏好植被覆蓋度較高的河濱環境，棲地廣適性鳥種則以離山區的距離為最重要的影響變數。 本研究結果釐清影響臺北市河濱地區陸域繁殖鳥種多樣性的環境因子，並了解棲地異質性與隔離度為影響河濱陸域繁殖鳥種的重要假說。期盼在未來河濱地區的經營管理上，若能考慮與山區的距離，建立良好的連結性，並提升河濱地區內部的棲地品質，將有效地透過河濱地區維持並增加臺北市的鳥類多樣性。The relationship between bird species richness （BSR） and urban environment is important for concerns about the negative impact of urbanization. However, recent studies have started to focus on the maintenance of urban BSR in the face of increasing human population and expanding cities, and have proposed hypotheses that could lead to an increase in BSR. Cities are typically located near large water bodies. Urban riparian zone is the hotspot of BSR. Compared with urban green spaces, riparian zones have contiguous and larger areas. In addition, habitat heterogeneity caused by irregular flood and disturbance provides various resources for birds, with many specialists living only in this area. We examined patterns of habitat use by birds at the local and landscape level during 3-6 months 2013 at 72 riparian plots along an urban gradient in Taipei city. Using generalized linear regression, we test the hypothesis of area （surrogated by width of riparian）, isolation （surrogated by distance from mountain）, productivity [surrogated by normalized difference vegetation index （NDVI）], heterogeneity （surrogated by habitat heterogeneity index and tree diversity）, and disturbance （surrogated by percentage of built area） respectively for BSR and bird guilds. Besides, ranking the relative importance of environmental factors by Akaike weight. We found that distance from mountain was the most important predictor of BSR. We suggest isolation is the primary process of BSR. Tree diversity, the second most important factor, was positively correlated with BSR; on the other hand, habitat specialist prefer the higher NDVI, and the distance from mountain are most important factor for habitat generalist. The results of this study to clarify the effects of environmental factors on the riparian zone of BSR and bird guild in Taipei, and construct relative importance of hierarchy. We also suggest establish connectivity with mountain, and improve habitat quality inside the riparian zone. It will effectively maintain and increase BSR. for building a biodiversity-friendly city.in Taipei前言 1 研究方法 4 研究樣區 4 鳥類資料 4 鳥類棲地同功群 5 環境變數 6 資料分析 8 結果 10 鳥類調查 10 鳥類棲地同功群分類結果 11 環境變數相關性 11 全模式診斷 11 複迴歸分析結果 11 環境變數之相對重要性結果 12 討論 13 環境因子與河濱地區鳥種多樣性的關係 13 環境因子與河濱地區鳥類棲地同功群的關係 16 保育之建議 18 參考文獻 1