TPO 23 integrated essay

The author states some theories that may cause the decline in population of cedar trees. However, the professor argues that all these theories are not convincing.

First, the reading explains that cedar bark beetle may cause the reduction of cedar trees by eating the bark. On the other hand the lecturer refutes this point by saying that cedar trees have chemical substances which give the trees the protection they need against beetles. These chemicals are poisonous to beetles so they do not eat healthy trees. Beetles actually eat trees that are already sick. So beetles are not the primary cause of killing cedar trees.

The second theory according to the writer is that bears claw the cedar trees and may lead to decline in the trees. In contrast, the lecturer opposes this theory by telling us that the reduction in number of cedar trees not only in the mainland of northwestern coast, but also in Island. Bears are not found in Island. This lead us to conclude that bears are not the main cause of decreasing number of cedar trees since cedar trees are decreasing with and without the presence of bears.

Finally, the author claims that third theory of killing and declining trees may because of climatic changes. When roots are growing in the late of the winter instead of early spring, this may lead to freeze the roots and they may die eventually. On the contrary, the professor refutes the last theory by explaining that cedar trees may be affected by lower elevation of worn more than by higher elevation of cold. The roots may be impacted by changing worm which leads to kill them more than cold in winter.