tpo 23

The lecture and the reading discuss possible reasons which cause the decline of yellow cedar trees. Although the reading passage provides three theories for declining the yellow cedar, the speaker refutes this idea for several reasons, which I will describe in this report.

First, the passage points out that some insects like the cedar bark beetle were attacked by the yellow cedar, and they ate the wood of trees and kill of them. The lecturer, in contrast, rejects this by claiming that the healthy yellow cedar more resistant to insects, and the tree produces the saturate liquid that can protect the tree from the attack of insects because this powerful liquid is poisoning insects and defend trees. However, if trees do not healthy, they would not produce powerful liquid, so cedar trees were not healthy, and they damaged from the attack of insects.

Furthermore, the passage states that beers claw trees and start to eat the tree bark as food, and it caused trees to become weakened. However, the speaker argues that all yellow cedar trees in the world were died and declined. Yellow cedar trees were located in the mainland and islands. In the islands, beers do not live and exist. So, the decline of trees in this place was not related to beers.

Finally, although the reading passage says that climate change is another reason for declining of cedar trees because the roots of trees were sensitive to the warm weather. The professor disagrees by mentioning that cedar trees have died in both higher elevation with a cooler climate and lower elevation with warmer weather. Thus this declining pattern counters the hypotheses of climate change role in yellow cedars' population decrease.