Final answer:
Human activities like dam construction and farming can transform ecosystems, creating habitat patches, while activities like deforestation or introducing non-native species can fragment habitats and contribute to species extinction.
Step-by-step explanation:
Human and natural forces can combine to create habitat patches through various mechanisms, where both ecological changes and anthropogenic activities alter the landscapes. One example includes the construction of dams, which is a human activity that alters the flow of rivers — humans respond to population pressures and the need for water in growing cities by building these structures.
The result is a transformation of ecosystems, such as turning wetlands into deserts or deserts into urban areas demanding high resources. In addition, farming impacts ecosystems by modifying environments through the clearing of land, like prairies and forests, to make way for agriculture. This can lead to fragmented habitats where only certain areas remain suitable for wildlife, thereby creating patches of natural habitat surrounded by human-altered landscapes.
Moreover, foundation species, such as certain types of trees in a forest, can physically modify the environment and create beneficial habitats for other species. However, when humans destroy these habitats, either by deforestation or other means, it can lead to the extinction of species that can't adapt to the altered conditions. Humans also engage in activities such as introducing non-native species which can disrupt local ecosystems and contribute to habitat fragmentation, thereby forming patches of the original habitat.