a plant requires nutrients to grow & soil contains nutrients for plants ->  plants use the nutrients in soil to grow  using resources decreases those resources & nutrients are a kind of resource ->  using nutrients decreases those nutrients  plants use the nutrients in soil to grow & using nutrients decreases those nutrients ->  plants can decrese the nutrients in soil  a rainforest is a kind of forest & a forest contains lots of plants / trees ->  a rainforest contains lots of plants  plants can decrese the nutrients in soil & a rainforest contains lots of plants -> the soil in a rainforest can be low in nutrients