TPO 23

The reading passage and the listening section are both discussing what causes populations of the yellow cedar decline. The article gives some convincing arguments but the speaker casts doubt on them and proposes several statements to refute them.

First of all, the essay mentions that the beetle is one of the reasons that reducing the yellow cedars. However, the lecturer disagrees with the argument by arguing that yellow ceders contain some toxic content. To be more specific, this toxic content would help the trees to kill the insects. Therefore, the parasites would cause the yellow cedars decline is not a fundamental reason.

Secondly, the article suggests that the brown bears' feeding habits would make the cedars decline, but the speaker disapproves on it by contending that the trees plant in both island and mainland of North America. To elaborate, the island does not have any brown bears, but the trees also decline. That is, the brown bears might not the reason that cause the yellow cedars decline.

Last bu not least, the reading proposes that climate change may be the reason that causes the cedars decline. Once again, the lecturer does not agree the essay, and provides that the lower temperature may be harmful for the trees is wrong. Furthermore, the speaker continues saying that the evidence shows that the trees in the higher elevation die more than the lower elevation. Therefore, this theory is totally not convincing.