When tornados strike forests, they can leave behind large gaps called blowdowns. In these gaps, most of the trees have been knocked over.
Fifteen years after a tornado had passed through a forest, scientists compared the characteristics of a blowdown to a similar area that the tornado had not impacted. The scientists measured the canopy cover, which is the percentage of ground area covered by trees. The canopy cover in the blowdown site was 45%, and the canopy cover in the non-impacted site was 80%. The table below shows the population densities of four forest species at the two sites.
Species Description Population Density
(number per 100 square feet)
Blowdown Non-Impacted Site
ash trees native hardwood 2 5
autumn olive non-native shrub 4 1
shagbark hickory native hardwood 1 3
Amur honeysuckle non-native shrub 5 2
Based on the information above, what is one way that a tornado impacts a forest community?
A.
It removes large hardwoods from the community, which decreases the habitat available to smaller plants.
B.
It increases light available on the forest floor, which can encourage the growth of non-native shrubs.
C.
It removes large hardwoods from the community, but these rapidly grow back to restore the forest.
D.
It decreases light available on the forest floor, which can encourage the growth of non-native shrubs.
