以嵌套結構檢視都市綠地對群集生態的影響

Abstract

都市化常造成自然環境改變，影響原先物種的組成與生存，導致多樣性降低。在維護生態上，都市綠地扮演至關重要的角色。本研究為探討都市綠地對於動物群集的影響，選取於台北市公園自2008年至2020年鳥類、蝴蝶、爬蟲類、蛙類群集生態調查資料有交集之 16 處公園，進行嵌套結構分析，以瞭解臺北市各公園綠地群集的相互隸屬程度，並利用斯皮爾曼相關性分析與雙樣本中位數差異檢定，檢視都市綠地對於嵌套結構及物種組成的影響性。研究結果顯示臺北市公園中的鳥類、蝴蝶、爬蟲類、蛙類均具有顯著的嵌套結構，儘管少部分物種有獨特的棲息偏好，但整體而言公園綠地可幫助整體群集存續，而棲地破碎化引起之邊緣效應則出現負相關。此外，移動能力較低的爬蟲類與蛙類有較強的嵌套結構，需更加審慎考量開發與棲地破碎化對群集造成的影響。根據此研究結果，建議保存或營造可供生物利用之水域及面積大、邊緣比例小的綠地，並營造多層林相結構、廣為種植原生樹木與蜜源植物，增進公園內現存植被的綠地品質，增強公園綠地在都市中維護生物多樣性的潛力。

Urbanization often causes changes in the natural environments, affects species composition and survival, and results in biodiversity reduction. Urban green space plays a critical role in biodiversity conservation. To investigate the influence of urban green space on community ecology, this study applied the nestedness analysis using the ecological survey data of birds, butterflies, reptiles, and frogs across 16 parks in the Taipei city from 2008 to 2020, to understand the affiliation of the inhabitant metacommunities in these parks. Then, I performed the Spearman’s rank correlation test and Mann-Whitney U test to investigate influence of urban green space on nestedness and species composition. Results found that birds, butterflies, reptiles, and frogs have significant nestedness among these parks. Although few species appeared unique habitat preferences, in general, parks and green spaces possessed a positive influence on the incidence of the community, while the fragmentation-induced edge effects showed a negative correlation. Besides, groups with lower mobility showed stronger nestedness, such like reptiles and frogs. This calls for careful consideration of urban development and habitat fragmentation on their impacts to these communities. Based on the results, during park planning and design, I suggest preserving or creating water zones and green space with large areas and low boundary proportion, improving the quality of the existing vegetation within parks by creating multilayer forest forms and planting native vegetation or nectariferous plants. These applications can help enhance the potential of parks in conserving biodiversity in urban areas.