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 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 insectis 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 cold winter nights. This frozen root damage may be capable of undermining the health of the whole tree, eventually killing it.
The reading states that the population of the yellow cedar is declining and provides three hypotheses to explain the reason. However, the professor explains that the researchers still do not know what kill these trees and he thinks that the reasons that the reading are mentioned are not adequate and he refutes each of the author's hypotheses.
First, the article claims that the insect parasites, especially the cedar bark beetle is attacked the trees by eating the wood. The professor refutes this point by saying that even healthy trees are more resistant to this kind of insects. He states that the bark and leaves of these trees have some kinds of chemicals that are poisonous to these insects and this substance kills them. Thus, these beetles are not the cause for death of these trees.
Second, the reading avers the bears that eat the tree bark which contain a high sugar content for them attributes the decline. However, the professor says that even though the bears damage some trees, but these trees exist in both island and mainlands and the bears are not living in islands. According to professor as these trees are declining in both places, thus bears cannot be the reason for their drop.
Third, the article posits that the gradual changes in climate may to be to blame. The professor opposes this point by saying that the author forget to account one important thing. Based on the lecture if the author is true, the trees in high elevation would die, but they found that trees in low elevation are dying more. Thus, the climate changes cannot be responsible for declining in number of these trees.
Discourse Markers used:
['but', 'first', 'however', 'if', 'may', 'second', 'so', 'still', 'third', 'thus', 'kind of']
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance in Part of Speech:
Nouns: 0.252459016393 0.261695866417 96% => OK
Verbs: 0.177049180328 0.158904122519 111% => OK
Adjectives: 0.0393442622951 0.0723426182421 54% => OK
Adverbs: 0.055737704918 0.0435111971325 128% => OK
Pronouns: 0.0229508196721 0.0277247811725 83% => OK
Prepositions: 0.118032786885 0.128828473217 92% => OK
Participles: 0.0393442622951 0.0370669169778 106% => OK
Conjunctions: 2.21401635796 2.5805825403 86% => OK
Infinitives: 0.0229508196721 0.0208969081088 110% => OK
Particles: 0.0 0.00154638098197 0% => OK
Determiners: 0.167213114754 0.128158765124 130% => OK
Modal_auxiliary: 0.0131147540984 0.0158828679856 83% => OK
WH_determiners: 0.0131147540984 0.0114777025283 114% => OK
Vocabulary words and sentences:
No of characters: 1620.0 1645.83664459 98% => OK
No of words: 278.0 271.125827815 103% => OK
Chars per words: 5.8273381295 6.08160592843 96% => OK
Fourth root words length: 4.08329915638 4.04852973271 101% => OK
words length more than 5 chars: 0.327338129496 0.374372842146 87% => OK
words length more than 6 chars: 0.219424460432 0.287516216867 76% => OK
words length more than 7 chars: 0.125899280576 0.187439937562 67% => OK
words length more than 8 chars: 0.0935251798561 0.113142543107 83% => OK
Word Length SD: 2.21401635796 2.5805825403 86% => OK
Unique words: 140.0 145.348785872 96% => OK
Unique words percentage: 0.503597122302 0.539623497131 93% => More unique words wanted or less content wanted.
Word variations: 48.9276709769 53.8517498576 91% => OK
How many sentences: 13.0 13.0529801325 100% => OK
Sentence length: 21.3846153846 21.7502111507 98% => OK
Sentence length SD: 38.4227496714 49.3711431718 78% => OK
Chars per sentence: 124.615384615 132.220823453 94% => OK
Words per sentence: 21.3846153846 21.7502111507 98% => OK
Discourse Markers: 0.846153846154 0.878197800319 96% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 3.39072847682 0% => OK
Readability: 43.3270614278 50.5018328374 86% => OK
Elegance: 1.60256410256 1.90840788429 84% => OK
Coherence and Cohesion:
Essay topic to essay body coherence: 0.239131386906 0.549887131256 43% => OK
Sentence sentence coherence: 0.173345340596 0.142949733639 121% => OK
Sentence sentence coherence SD: 0.0674943614827 0.0787303798458 86% => OK
Sentence paragraph coherence: 0.654092934233 0.631733273073 104% => OK
Sentence paragraph coherence SD: 0.108937102641 0.139662658121 78% => OK
Sentence topic coherence: 0.125552675256 0.266732575781 47% => OK
Sentence topic coherence SD: 0.0436794756159 0.103435571967 42% => OK
Paragraph paragraph coherence: 0.519293781753 0.414875509568 125% => OK
Paragraph paragraph coherence SD: 0.0458375506351 0.0530846634433 86% => OK
Paragraph topic coherence: 0.180547992672 0.40443939384 45% => OK
Paragraph topic coherence SD: 0.0284324064549 0.0528353158467 54% => The ideas may be duplicated in paragraphs.
Task Achievement:
Sentences with positive sentiment : 2.0 4.33554083885 46% => OK
Sentences with negative sentiment : 9.0 4.45695364238 202% => OK
Sentences with neutral sentiment: 2.0 4.26048565121 47% => OK
Positive topic words: 2.0 3.49668874172 57% => OK
Negative topic words: 7.0 3.62251655629 193% => OK
Neutral topic words: 2.0 3.1766004415 63% => OK
Total topic words: 11.0 10.2958057395 107% => OK
What are sentences with positive/Negative/neutral sentiment?
---------------------
Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 Out of 30
---------------------
Note: This is not the final score. The e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.