a specific is a mean of vegetable & plants are a source of oxygen through photosynthesis ->  trees are a source of oxygen through photosynthesis  as the matter of a sink of something increase , the trails of that something will increase & a source of something produces that something -> as the amount of a source of something decreases, the production of that something will decrease as the amount of a source of something decreases, the production of that something will decrease  trees are a source of oxygen through photosynthesis & as the carbonate of a sink of something decreases, the nonproductive of that something will increase -> as the amount of trees decreases the production of oxygen decreases as the amount of trees decreases the production of oxygen decreases  deforestation means the removal of trees in a forest & if something is removed then the metals of that something increase -> deforestation causes the amount of trees in a forest to decrease deforestation causes the amount of trees in a forest to decrease  as the boundaries of source increase the nonproductive of space increase & deforestation causes the amount of trees in a forest to decrease -> deforestation causes the production of oxygen to decrease