Answer:
The presence of predators of deer which does not allow increase in the population of deer year after year.
Explanation:
In an forest ecosystem, one animal controls the population of another organisms and thus there is no increase in the population of that organism and the ecosystem is in equilibrium state. The population of deer did not increase due to the presence of predators such as lion, cheetah etc and the net population is 0.
D phytoplankton i believe
Answer: the answer is water storage
Explanation: i just got it right
Hmmm let me think.........