Department of Entomology, Purdue University, West Lafayette, Indiana, United States of America.
PLoS One. 2012;7(8):e41729. doi: 10.1371/journal.pone.0041729. Epub 2012 Aug 2.
Numerous studies have examined the effect of urbanization on species richness and most studies implicate urbanization as the major cause of biodiversity loss. However, no study has identified an explicit connection between urbanization and biodiversity loss as the impact of urbanization is typically inferred indirectly by comparing species diversity along urban-rural gradients at a single time point. A different approach is to focus on the temporal rather than the spatial aspect and perform "before and after" studies where species diversity is cataloged over time in the same sites. The current study examined changes in ant abundance and diversity associated with the conversion of natural habitats into urban habitats. Ant abundance and diversity were tracked in forested sites that became urbanized through construction and were examined at 3 time points - before, during, and after construction. On average, 4.3 ± 1.2 unique species were detected in undisturbed plots prior to construction. Ant diversity decreased to 0.7 ± 0.8 species in plots undergoing construction and 1.5 ± 1.1 species in plots 1 year after construction was completed. With regard to species richness, urbanization resulted in the permanent loss of 17 of the 20 species initially present in the study plots. Recovery was slow and only 3 species were present right after construction was completed and 4 species were present 1 year after construction was completed. The second objective examined ant fauna recovery in developed residential lots based on time since construction, neighboring habitat quality, pesticide inputs, and the presence of invasive ants. Ant diversity was positively correlated with factors that promoted ecological recovery and negatively correlated with factors that promoted ecological degradation. Taken together, these results address a critical gap in our knowledge by characterizing the short- and long-term the effects of urbanization on the loss of ant biodiversity.
许多研究都考察了城市化对物种丰富度的影响，大多数研究认为城市化是生物多样性丧失的主要原因。然而，没有研究明确指出城市化与生物多样性丧失之间的联系，因为城市化的影响通常是通过在单个时间点比较城乡梯度上的物种多样性来间接推断的。另一种方法是关注时间而不是空间方面，并进行“前后”研究，即在同一地点随时间记录物种多样性。本研究考察了由于将自然栖息地转变为城市栖息地而导致的蚂蚁丰度和多样性的变化。在通过建设而变为城市化的森林地区追踪了蚂蚁的丰度和多样性，并在 3 个时间点进行了检查-建设之前、建设期间和建设之后。平均而言，在建设之前的未受干扰的地块中检测到 4.3 ± 1.2 种独特的物种。在正在建设中的地块中，蚂蚁多样性下降到 0.7 ± 0.8 种，而在建设完成 1 年后的地块中则为 1.5 ± 1.1 种。关于物种丰富度，城市化导致了研究地块中最初存在的 20 个物种中的 17 个永久丧失。恢复缓慢，只有 3 种在建设完成后立即出现，4 种在建设完成 1 年后出现。第二个目标是根据建设后的时间、邻近栖息地质量、农药投入和入侵蚂蚁的存在，考察已开发住宅用地中蚂蚁动物群的恢复情况。蚂蚁多样性与促进生态恢复的因素呈正相关，与促进生态退化的因素呈负相关。综上所述，这些结果通过描述城市化对蚂蚁生物多样性丧失的短期和长期影响，填补了我们知识中的一个关键空白。
