The first trophic level that would likely suffer would be the primary producers. The first thing that usually occurs as humans move into or influence an area would be clearing the land fir the purpose of creating infrastructure for development or for agricultural purposes. This is the primary cause of deforestation globally. As the first trophic level is affected so too are the other levels in an ecosystem.
Individuals with the most favorable traits survive and reproduce'
The forces of nature that are constantly reshaping the sandy beach are: the waves.
Answer: The correct answer is (a)Spring and fall when warm and cold water mixes
Spring and fall when the warm and the cold water mixes and the mixing of water evenly distributes the oxygen present in lake. During winter the cold water is below the ice and the different areas of lake have different concentration of dissolved oxygen. In summer the warm water lies above the cold water, here also the concentration of dissolved oxygen varies.
Hence, during spring and fall the warm water and cold water mixes which evenly distributes the dissolved oxygen present in lake.