Question

figure 1 shows changes in forest floor biomass over 50 years. figure 1 which event could be represented by the graph in figure 1? secondary succession after a fire primary succession after a volcanic eruption secondary succession after a glacier recedes primary succession after a mudslide

Explanation:

1. Secondary succession occurs in an area that has pre - existing soil and some remaining organisms. A fire can destroy above - ground vegetation but leave the soil and root systems intact, leading to secondary succession. The graph shows a decrease in forest floor biomass (like after a fire) followed by an increase as new plants grow.
2. Primary succession occurs in areas with no pre - existing soil, such as after a volcanic eruption (lava covers the area creating new, barren land), after a glacier recedes (leaving bare rock), or after a mudslide that removes all soil and organisms. These scenarios do not match the graph as they start from a more barren state.

Answer:

secondary succession after a fire