Silva Carmen Paz, García Cristóbal E, Estay Sergio A, Barbosa Olga
Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile, Valdivia, Chile.
Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile, Valdivia, Chile; Center for Applied Ecology and Sustainability (CAPES), Santiago, Chile.
PLoS One. 2015 Sep 30;10(9):e0138120. doi: 10.1371/journal.pone.0138120. eCollection 2015.
There is mounting evidence that urban areas influence biodiversity. Generalizations however require that multiple urban areas on multiple continents be examined. Here we evaluated the role of urban areas on avian diversity for a South American city, allowing us to examine the effects of urban features common worldwide, using the city of Valdivia, Chile as case study. We assessed the number of birds and their relative abundance in 152 grid cells of equal size (250 m2) distributed across the city. We estimated nine independent variables: land cover diversity (DC), building density (BD), impervious surface (IS),municipal green space (MG),non-municipal green space (NG), domestic garden space (DG), distance to the periphery (DP), social welfare index (SW), and vegetation diversity (RV). Impervious surface represent 41.8% of the study area, while municipal green, non-municipal green and domestic garden represent 11.6%, 23.6% and 16% of the non- man made surface. Exotic vegetation species represent 74.6% of the total species identified across the city. We found 32 bird species, all native with the exception of House Sparrow and Rock Pigeon. The most common species were House Sparrow and Chilean Swallow. Total bird richness responds negatively to IS and MG, while native bird richness responds positively to NG and negatively to BD, IS DG and, RV. Total abundance increase in areas with higher values of DC and BD, and decrease in areas of higher values of IS, SW and VR. Native bird abundance responds positively to NG and negatively to BD, IS MG, DG and RV. Our results suggest that not all the general patterns described in previous studies, conducted mainly in the USA, Europe, and Australia, can be applied to Latin American cities, having important implications for urban planning. Conservation efforts should focus on non-municipal areas, which harbor higher bird diversity, while municipal green areas need to be improved to include elements that can enhance habitat quality for birds and other species. These findings are relevant for urban planning in where both types of green space need to be considered, especially non-municipal green areas, which includes wetlands, today critically threatened by urban development.
越来越多的证据表明城市地区会影响生物多样性。然而，要进行概括就需要对多个大陆的多个城市地区进行考察。在此，我们以智利的瓦尔迪维亚市为案例研究，评估了城市地区对南美洲一个城市鸟类多样性的作用，从而能够考察全球常见的城市特征所产生的影响。我们评估了分布在全市的152个大小相等（250平方米）的网格单元中的鸟类数量及其相对丰度。我们估算了九个独立变量：土地覆盖多样性（DC）、建筑密度（BD）、不透水表面（IS）、市政绿地（MG）、非市政绿地（NG）、家庭花园空间（DG）、到城市边缘的距离（DP）、社会福利指数（SW）以及植被多样性（RV）。不透水表面占研究区域的41.8%，而市政绿地、非市政绿地和家庭花园分别占非人工表面的11.6%、23.6%和16%。外来植被物种占全市已识别物种总数的74.6%。我们发现了32种鸟类，除了家麻雀和原鸽外均为本地物种。最常见的物种是家麻雀和智利燕。鸟类总丰富度对IS和MG呈负响应，而本地鸟类丰富度对NG呈正响应，对BD、IS、DG和RV呈负响应。总丰度在DC和BD值较高的区域增加，在IS、SW和VR值较高的区域减少。本地鸟类丰度对NG呈正响应，对BD、IS、MG、DG和RV呈负响应。我们的研究结果表明，之前主要在美国、欧洲和澳大利亚进行的研究中所描述的并非所有一般模式都能应用于拉丁美洲城市，这对城市规划具有重要意义。保护工作应聚焦于非市政区域，这些区域拥有更高的鸟类多样性，同时市政绿地需要加以改善，以纳入能够提升鸟类和其他物种栖息地质量的要素。这些发现对于城市规划具有相关性，因为两种类型的绿地都需要被考虑，尤其是非市政绿地，其中包括如今受到城市发展严重威胁的湿地。
