clearing forests means cutting down a large amount of trees in a forest & cutting down trees in a forest causes the number of trees to decrease in that forest ->  clearing a forest causes the number of trees to greatly decrease in that forest  clearing a forest causes the number of trees to greatly decrease in that forest & deforestation is when the number of trees / organisms in a forest decreases ->  clearing a forest causes deforestation to increase  clearing a forest causes deforestation to increase & as the deforestation increases , the soil erosion will increase -> clearing a forest causes increased soil erosion