CBSE Class 10 Science 2019 · Paper 31/4/3 · Question 6

Roles of forests in conserving the environment (any three): 1. They bring rainfall and keep the water cycle going, through transpiration. 2. They purify the air and reduce pollution, taking in carbon dioxide and giving out oxygen. 3. Their roots hold the soil, preventing soil erosion and floods, and help rainwater soak into the ground. (They are also home to many plants and animals.) How forests get depleted: By deforestation, the cutting and clearing of trees for timber, fuel wood and paper and for land for farming, housing, roads, industries, mining and dams, to meet the needs of an increasing population; overgrazing and forest fires also destroy forests. Consequences of deforestation (any two): 1. Less rainfall and a disturbed water cycle. 2. Soil erosion and floods, with loss of soil fertility. Other consequences that also earn credit: loss of wildlife and imbalance in the ecosystem, more carbon dioxide in the air (global warming), and fewer forest products.