What is the impact of urbanization on biodiversity?

Urbanization tends to decrease biodiversity in many cases because it leads to habitat destruction, fragmentation, and degradation. As urban areas expand, natural habitats such as forests, wetlands, and grasslands are cleared to make way for housing, roads, and other infrastructure. This loss of habitat directly reduces the number of species that can live in a given area, leading to declines in population sizes and the extinction of some species.

Additionally, urban environments often create conditions that are unsuitable for many native species. Factors such as pollution, increased human activity, and the introduction of invasive species can further exacerbate the decline in local biodiversity. Urbanization can also isolate populations of species, making it difficult for them to migrate, reproduce, or find food sources, which can further reduce genetic diversity and resilience.

The misconception that urbanization might enhance biodiversity arises from the observation that some species, particularly those that are adaptable and thrive in human-altered landscapes, may increase in numbers. However, this often comes at the expense of native species, leading to a net loss in overall biodiversity. Therefore, the impact of urbanization is more accurately characterized by a decrease in biodiversity in many contexts.