tpo 23Populations of the yellow cedar, a species of tree that is common in northwestern North America, have been steadily declining for more than a century now, since about 1880. Scientists have advanced several hypotheses to explain this decline.One hypo

The reading and lecture are both about yellow cedar which is drastically declined since 1880. The author of the reading feels that there are several reasons for this decline and presents some aspect. The lecturer challenged the claim made by the author. He is on the opinion that unfortunately, we do not know the cause and none of the reasons is adequate. To begin with, the author argues that some insects like beetle eat the yellow cedar and lay eggs inside of the wood. He also states that beetle is one of the causes of declination. The specific argument is challenged by the lecturer. He mentions that healthy yellow cedar is resistance and unlikely suffers by the beetle. He also elaborates by mentioning that beetle attack the died tree that already dead. Secondly, the author suggests that bears eat the sugar content of the tree bark and sometimes damage the tree with the claw. He also claims that this aggressive behave might damage the tree. The lecturer rebuts this by mentioning that bear might damage some of the trees but not the overall reason to decrease. He also additionally says in northwestern North America may be the cause of the bear but in other regions the tree also declines. Thus, the bear is not the main cause. Third, the author posits that due to the climate change root system of the yellow cedar start growing in the late winter. He also mentions that as a result, the root suffers from freezing and causing harm to the tree. In contrast, the lecturer position is that reading passage forgets to account some fact. He also adds that in the lower elevation where the tree dies climate is cold and higher elevation where the climate is warm. But, in this warm area trees are more declining. Thus, it is not the actual cause.