TPO.23

The article states about three hypotheses that are responsible to reduce the yellow cedar trees in northwestern of North America. However, the professor in the lecture casts serious doubt on the passage by using a number of points that are contrary to each of the author's reasons.

First of all, the reading claims that trees diminishing is related to insect parasite population especially cedar bark beetle. In contrast, the professor refutes this point by saying that it is not true because yellow cedar trees are more resistant than other trees. He mentions that it is unlikely for yellow cedar trees to suffer from these parasites. As a result, beetle in not fundamental reason to decline trees.

On another hand, the article posits that brown bears are responsible for this catastrophe due to the fact that they like to eat tree bark's sugar. However, the teacher describes that beers are not responsible because the population of yellow cedar trees have decreased in entire the region. However, we cannot find ant beer in some islands. As a result we should not blame beers for this situation.

Finally, the article makes it clear that we can argument climate changes causes some damages towards yellow cedar trees. On the other hand, the lecturer opposes this point by explaining that it is not realistic. We also learn that freezing is not responsible because more die in trees have happened in low districts instead of high elevations.