Australian Research Centre for Urban Ecology, Royal Botanic Gardens Melbourne, c/o School of Botany, University of Melbourne, Victoria 3010 Australia.
Ecol Appl. 2011 Mar;21(2):378-90. doi: 10.1890/10-0390.1.
Urbanization is currently responsible for widespread declines of amphibian populations globally through the loss, isolation, and degradation of habitat. However, it is not clear how urbanization affects amphibian communities at both local (pond) and landscape scales. We assessed the breeding distribution of frogs in ponds along an urban-rural gradient in Greater Melbourne, Australia, and examined community relationships with habitat quality and landscape context. We sampled frog larvae at 65 ponds on four separate occasions and collected data on local pond and landscape variables. Using Bayesian Poisson regression modeling we found that species richness decreased at ponds surrounded by high densities of human residents and at ponds with high water conductivity, whereas species richness increased substantially at ponds surrounded by a high proportion of green open space. Ordination of individual species presence-absence data by canonical correspondence analysis largely confirmed these findings. Ordination also highlighted the negative influences of pond shading and density of predatory fish, and the positive influence of aquatic vegetation, on community composition. Individual species' responses to urbanization varied. Urbanization had strong negative effects on species that were associated with well-vegetated, sunny, fish-free ponds. Our study highlights the importance of strategic management actions in urban landscapes to improve terrestrial habitat and connectivity around ponds and other wetlands, and local management actions to improve water quality, remove predatory fish, and plant aquatic vegetation at breeding sites.
城市化是目前导致全球范围内两栖动物种群广泛减少的主要原因，其途径包括生境的丧失、隔离和退化。然而，城市化如何影响局部（池塘）和景观尺度上的两栖动物群落尚不清楚。我们评估了在澳大利亚大墨尔本地区城乡梯度上的池塘中青蛙的繁殖分布，并研究了与栖息地质量和景观背景相关的群落关系。我们在四个不同的时间点对 65 个池塘中的青蛙幼虫进行了采样，并收集了有关当地池塘和景观变量的数据。我们使用贝叶斯泊松回归模型发现，在被高密度人类居民包围的池塘和具有高电导率的池塘中，物种丰富度降低，而在被高比例绿地包围的池塘中，物种丰富度则大幅增加。通过典范对应分析对个体物种存在缺失数据的排序在很大程度上证实了这些发现。排序还突出了池塘遮荫和掠食性鱼类密度对群落组成的负面影响，以及水生植被对群落组成的积极影响。个别物种对城市化的反应各不相同。城市化对与植被良好、阳光充足、无鱼类的池塘相关的物种有很强的负面影响。我们的研究强调了在城市景观中采取战略管理行动以改善池塘和其他湿地周围的陆地栖息地和连通性的重要性，以及采取当地管理行动以改善水质、清除掠食性鱼类和在繁殖地种植水生植被的重要性。
