How trees grow
A common misconception is that trees grow only using the contents from the soil.
As a result, when trees or new vegetation grow over time, it would deplete the soil.
Although there’s some truth to this, most of plant growth is taken from the contents of the air and rain water.
Photosynthesis and plant growth
The photosynthesis process produces sugars to create the trunk and other structures of the tree.
Instead, the nutrients that plants get from soils mostly aren’t used as part of the main body and structure of a tree.
Plants use these soil nutrients for the more complex structures within plants, such as functional proteins and enzymes.
This means that most of the dry mass of trees is made from the contents of the air and water.
Gas burnt in your car ends up in plant material
When your car burns gasoline, the fossil fuels are released into the air as carbon dioxide and water vapor.
It may stay in the atmosphere for awhile, but eventually plants consume it during photosynthesis.
So that same weight from the tank of gasoline gets converted into wood or plant material by photosynthesis.
Given how many cars are being driven daily, plants have access to plenty of “material” for their growth. They just need the ideal conditions to grow.