Final answer:
The primary reason for the decline in species diversity due to deforestation is habitat destruction. Forests provide critical habitat for numerous species, and when they are cut down, it disrupts the interconnected web of life within ecosystems.
Step-by-step explanation:
The primary reason for the decline in the diversity of species due to deforestation is habitat destruction. When forests are cut down, the habitat critical for the survival of native species is reduced. This affects a wide range of organisms that rely on forest ecosystems for food, shelter, and breeding grounds.
For example, tropical rainforests in the Amazon Basin are being cut down at an unsustainable rate. This leads to the loss of habitat for numerous species, many of which are endemic to these forests. The cleared areas are often converted into cattle ranches or plantations, further reducing the suitability of the habitat for forest-dwelling species.
Overall, deforestation disrupts the interconnected web of life within ecosystems, resulting in a decline in species diversity.