Reading Passage Analysis

e author of the reading passage thinks that there are some reasons to explain the decreasing population of the yellow cedar. Meanwhile, the professor states that there reasons in the reading passage are not convincing and we still do not know about the decline.
To begin with, while the passage states that the decline may be caused by insects, such as cedar bark beetles. The lecture argues that healthy cedars are not easily attacked by beetles. There are powerful chemicals in their leaves which are poisonous to the insects. Those which are killed by insects are sick when it is attacked. So, the decline is not caused by insects.
In addition, the author says that the brown bears may be responsible for the decrease, for they may eat the tree bark
for sugar. The professor states that the brown bears will not cause an overall decline the yellow cedar's population. Not only the number of the cedars on the mainland decreases, the cedar population on islands declines as well. As there are no brown bears on the islands, the decline is not caused by brown bears.
In the end, the author suggests that the climate change may make the roots more sensitive and cause the decrease. The lecture, however, argues that the number of death in warmer areas is larger than the number in colder areas. If the decline is caused by climate change, it will affect trees in colder areas more. So the climate change is not responsible for the decline.
To conclude, the author thinks the decline of yellow cedars is caused by several reasons, but the lecture thinks that they are not convincing.