TPO23(integrated)

In this set of materials, both the reading passage and the lecture discussed the possible reasons for the decline occurred recently in the population of yellow cedar trees. The reading firmly stated that there are some hypotheses found by scientists for that phenomenon. However, the professor repudiated what stated in the reading resting upon fallacious premises and provides three counterclaims proofing that there is no definite explanation for that declination.

Firstly, the article argued that insect parasites, specially beetles, are to be blamed. The professor contradicted this point by acknowledging that as the stem of this plant are saturated with powerful chemicals; they considered to be more resistant than other plants of that region. Consequently, beetles might harm themselves after attacking a plant like the yellow cedar trees.

Secondly, the article claimed that brown bears have been accepted as a factor that attributes in the population decline of the aforementioned plant. Notwithstanding, the lecture highlighted that as there are no bears on islands of North America, but there has been an overall decline in the number of that plant both on main lands and islands, therefore, there is no relation between this declination and existance of bears.

Lastly, the reading contended that climate changes are another factor that contributed in decreasing the number of yellow cedar trees. This seemed to be incorrect as explained in the lecture. The speaker articulated that if the climate is effective on the freezing the roots of that tree, the number of these species have to be unchanged in low elevation parts of the region. But this is not what happened in reality.