The development of cities in the nineteenth century had significant effects on ecology. As urban populations grew rapidly due to industrialization and rural-to-urban migration, cities expanded and transformed landscapes, leading to various ecological changes.

1. Deforestation: The demand for timber and land for urban expansion led to extensive deforestation in many areas. Forests were cleared to make way for buildings, roads, and infrastructure, resulting in the loss of habitat for many plant and animal species.

2. Loss of wetlands: Wetlands were drained and filled to create space for urban development. Wetlands play a crucial role in maintaining water quality, regulating water flow, and providing habitat for a diverse range of species. Their loss led to the decline of wetland-dependent species and disrupted natural water cycles.

3. Air and water pollution: The rapid industrialization and increased use of fossil fuels in cities resulted in severe air and water pollution. Factories emitted toxic gases and pollutants, while urban waste and sewage were often disposed of in rivers and streams, contaminating water sources. This pollution negatively impacted the health and survival of both humans and wildlife.

4. Loss of biodiversity: Urbanization led to the destruction and fragmentation of natural habitats, resulting in the decline and extinction of many plant and animal species. As cities expanded, native vegetation was replaced by concrete and buildings, leaving little space for wildlife. Urban areas typically have reduced biodiversity compared to natural ecosystems.

5. Altered ecosystems: The construction of buildings, roads, and infrastructure disrupted natural ecosystems and altered the ecological balance. Urban areas often have altered microclimates, with increased temperatures due to the urban heat island effect. This change affects the distribution and behavior of plants and animals and can lead to the proliferation of non-native species.

6. Changes in hydrology: The alteration of landscapes through urban development can impact natural water cycles. The construction of impermeable surfaces like roads and buildings reduces the infiltration of rainwater into the ground, leading to increased surface runoff and the potential for flooding. Changes in hydrology can also negatively affect aquatic ecosystems and water availability.

Overall, nineteenth-century city development had detrimental effects on ecology, leading to deforestation, loss of wetlands, air and water pollution, loss of biodiversity, altered ecosystems, and changes in hydrology. These impacts continue to shape urban environments and pose ongoing challenges for sustainability and conservation efforts.