Final answer:
Urban environmental modifications, such as the removal of native vegetation cover and urbanization, lead to changes in habitat conditions and climatic processes, affecting plant species distributions, seed dispersal, and the introduction of invasive species.
Step-by-step explanation:
Urban environmental modifications significantly alter vegetation cover and climatic processes, leading to various ecological changes. The removal of large tracts of native vegetation in urban areas, which can be seen as extreme forms of habitat modification, has long-term impacts on physical processes such as solar radiation and the movement of wind and water. These changes are particularly pronounced at the edges of habitat fragments, with phenomena like 'edge effects' causing variations in light, humidity, temperature, and wind compared to the forest interior. Such physical changes can influence biological processes, affecting plant growth, reproduction, and ecological interactions.
Urbanization does not only cause immediate transformation of natural habitats, but also implies a permanent replacement by artificial structures. This results in substantial disturbances to the existing plant species and paves the way for new, often invasive, species to colonize these areas. Furthermore, climate change is expected to exacerbate these disruptions by modifying disturbance regimes including events like floods, cyclones, and fires which selectively affect both native and invasive species. The climatic stresses and altered disturbance patterns contribute to changes in the distribution and abundance of alien plant species.
At larger scales, changes in temperature and rainfall patterns are expected to shift plant species distribution, impact seed dispersal mechanisms, and influence the success of plant establishment and regeneration. Urban ecosystems, as well as the introduction of invasive species, can significantly alter these ecological dynamics, presenting unique challenges to the conservation of native biodiversity.