Essay topics: 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 to explain this decline.

Essay topics:

Essay topics: 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 to explain this decline.

One hypothesis is that the yellow cedar decline may be caused by insect parasites, specifically the cedar bark beetle. This beetle is known to attack cedar trees; the beetle larvae eat the wood. There have been recorded instances of sustained beetle attacks overwhelming and killing yellow cedars, so this insect is a good candidate for the cause of the tree’s decline.

A second hypothesis attributes the decline to brown bears. Bears sometimes claw at the cedars in order to eat the tree bark, which has a high sugar content. In fact, the cedar bark can contain as much sugar as the wild berries that are a staple of the bears’ diet. Although the bears’ clawing is unlikely to destroy trees by itself, their aggressive feeding habits may critically weaken enough trees to be responsible for the decline.

The third hypothesis states that gradual changes of climate may be to blame. Over the last hundred years, the patterns of seasonal as well as day-to-day temperatures have changed in northwestern North America. These changes have affected the root systems of the yellow cedar trees: the fine surface roots now start growing in the late winter rather than in the early spring. The change in the timing of root growth may have significant consequences. Growing roots are sensitive and are therefore likely to suffer damage from partial freezing on clod winter nights. This frozen root damage may be capable of undermining the health of the whole tree, eventually killing it.

According to the lecturer and the reading, there are several positive points which have been discussed about yellow cedars and several negative point about yellow cedar. The lecturer explains that the three hypothesis about yellow cedar's decline that is mentioned in the reading are not accurate. However, the reading passage contends that Scientists have advanced several hypotheses to explain this decline.

The first point the lecturer makes it that we don't know the exact reasons of decline. According to the professor cedar bark beetle is more resistant than other trees, it's saturated with powerful chemicals. if the trees are attacked by parasite so maybe those trees were already sick. This point from the lecturer contrasts with the reading because the reading only says that yellow cedar's decline is caused by insect parasites.

Another point that the lecturer uses to cast doubt on the reading is there is no brown beers in northwestern North America. The lecturer claims that since that decline occurs with or without bear so the bear is not
responsible. However, the reading only states that Bears sometimes claw at the cedars in order to eat the tree bark, which has a high sugar content

finally the professor stated that, on the contrary of the reading, cedar trees primarily die at lower elevation where it is warmer than higher elevation where it is colder. In other words, if cold was the main cause of death so all the trees could be dead. This contradicts the final idea of the reading passage because it only says that Growing roots are sensitive and are therefore likely to suffer damage from partial freezing on clod winter nights. This frozen root damage may be capable of undermining the health of the whole tree, eventually killing it.

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Score: 25 in 30
Category: Very Good Excellent
No. of Grammatical Errors: 0 2
No. of Spelling Errors: 0 2
No. of Sentences: 13 12
No. of Words: 295 250
No. of Characters: 1447 1200
No. of Different Words: 160 150
Fourth Root of Number of Words: 4.144 4.2
Average Word Length: 4.905 4.6
Word Length SD: 2.283 2.4
No. of Words greater than 5 chars: 104 80
No. of Words greater than 6 chars: 79 60
No. of Words greater than 7 chars: 42 40
No. of Words greater than 8 chars: 25 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 22.692 21.0
Sentence Length SD: 5.511 7.5
Use of Discourse Markers (%): 0.692 0.12
Sentence-Text Coherence: 0.378 0.35
Sentence-Para Coherence: 0.593 0.50
Sentence-Sentence Coherence: 0.099 0.07
Number of Paragraphs: 4 4