Question

a large tree was blown over in a forest during a storm. the data table below shows the number of plants and plant species in the immediate area before and after the large tree fell. vegetation before and after tree falling
before: number of plants 4, number of plant species 3; 3 months after: 11, 5; 6 months after: 14, 6
which of the following explains why the population changed after this disruption?
a. the gap created when the large tree fell allowed sunlight to reach the previously shaded forest floor
b. the impact of the large tree when it fell caused many of the smaller plants below it to die.
c. the large tree covered up the soil after it fell and made the area unusable by other plants
d. the large tree released many of its seeds when it fell and those seedlings replaced the tree

Explanation:

• Option A: When the large tree fell, the gap created allowed sunlight to reach the previously shaded forest floor. This increased sunlight availability can promote the growth of more plants and the emergence of new plant species (as seen in the data where both number of plants and species increased over time), which explains the population change.
• Option B: If the large tree falling caused smaller plants to die, we would expect a decrease in plant numbers and species, but the data shows an increase, so B is incorrect.
• Option C: If the area became unusable for other plants, plant numbers and species should decrease, not increase, so C is incorrect.
• Option D: The tree falling and releasing seeds would likely lead to its own seedlings replacing it, but the data shows an increase in plant species (implying new species, not just the tree's seedlings), so D is less likely.

Answer:

A. The gap created when the large tree fell allowed sunlight to reach the previously shaded forest floor