TPO-23 - Integrated Writing Task Populations 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 expla

The reading passage and lecturer are both discussing yellow cedar and its species and its species decline for more thatn a century now.

The lecturer cast doubt on the claims made in the reading. The author in the reading believes that one theory could be insect parasite. The lecturer says that insect infestation can not be the reason as it was mentioned in the reading. Because of the fact that cedar has powerful chemical which insects can not be the fundamental crisis.

Moreover the author states that brown bears also use food from cedar trees because bark contains sugar. The lecturer rebuts this argument by suggesting that bear can not also damage same kind of trees in Northwest America, no bears is there.

Finally, author mentions that gradual changes in climate caused this. These changes has affected the root system of cedar trees. The lecturer on the other hand states that roots can not be damaged of frost damage. He puts forth the idea that warmth was more responsible than cold weather.