base your answer on the topographic map below and on your knowledge of earth science points XYZ indicate Service locations elevations are shown in meters calculate the gradient of Otter Creek in meters per kilometer between points y and z.

the answer is trees if i'm not mistaken

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link:

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs