Answer:
The population of the species.
Explanation:
This one took a bit of thought, but here is my conclusion.
If there is more population, there is higher demand on resources such as food, water, and shelter. With less to go around, the species will start to compete more for the limited resources, therefore increasing the competition.
Hope this helps!
Answer:
i stongly belive that "Lungs of the Earth" refers to the trees
Explanation: because trees act just like lungs
