Major consequences of deforestation are

Major consequences of deforestation are destruction of natural habitat of wild species, soil erosion, biodiversity loss (All of the above).

Forest is an area dominated by trees and vegetation. Various living organisms inhabit forest and survive on its resources, including humans. Cutting of trees on a large scale is called deforestation. When these large number of trees of an area are cut, it leads to mass destruction of not only trees but also the wildlife, hence there is biodiversity loss along with the destruction of natural habitat. Since plant roots helps in keeping the soil firm to prevent soil erosion, the cutting down of trees loosens the soil leading to soil erosion.

Wordcheck: Biodiversity - Variety of animals, plants, and microorganisms generally found in a region.
                      Habitat - Natural home or environment of a living organism.
                      Soil Erosion - Loss of top layer of soil.