Answer:
The key concept is - causes and effects of deforestation.
Step-by-step explanation:
In this paragraph, the author is explaining the meaning, causes and effects of deforestation and why it should be stopped. He explained deforestation in initial sentences and then explained it can cause by humans or occur naturally. The author further explained that human is a key factor in the loss of forest for their livelihood and economic benefits.
The author explains in the concluding sentences that it should be stopped as the forest have an important role in life and the environment as it provides habitat and also maintains the ecosystem.