The effects may be good or bad. We alter habitats to fit our own needs for food, materials, and space. Mining, filling in wetlands for buildings and farming, and making roads and new towns change wildlife habitat, often causing harm. When a wetland is filled, ducks can't feed or nest. Other animals lose their homes, too.
Habitat management is the science and art of changing habitat.
The goal of habitat management is to increase wildlife populations. We must take care of the habitat that is left so we don't lose plants and animals from the earth forever. Habitat management includes building nest boxes. It includes planting trees and grasses in some places, and cutting trees in other places. Cutting trees to open forests helps white-tailed deer but not some owls, warblers, and woodpeckers.