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.
Both the lecture and the reading material discuss the population of yellow cedar, a tree species that is native to northern America. The reading to be more specific argues that the decline of yellow cedar population is resulted from three main factors namely the attack of yellow bark beetle, the feeding of brown bears and the change of climate. On the contrary the lecturer holds the belief and states that all the factors mentioned in the reading are incorrect.
The reading begins by stating that insects such as cedar bark beetle are responsible for the reducing number of the yellow cedar species. This is challenged by the professor, who feels strong that this theory is wrongly depicted. He further explains that yellow cedar is extremely resistant to insects as it let off a powerful chemical that is harmful to insects. Hence, the trees that cedar beetles are able to attack are the ones which are already week and about to die.
The reading passage then points out that the brown bears is another factor causing the yellow cedar population to fall. The professor, in contrast, asserts that bears are not causing the mass declination of northwestern North America native trees. He supports this argument by discussing the fact that bears do not live on the islands, yet the quantity of yellow cedar trees is still dropping there.
The reading finishes by arguing that yellow cedar trees are declining in number as a result of climate change as it causes the change in the timing of root growth leading to the partial frozen roots. The lecturer refutes this idea by claiming that the trees on the low elevation which are exposed to a warmer climate are dying even more than trees on high elevation Thus, it is not the climate change to blame for on the declination of yellow cedar population.
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Discourse Markers used:
['hence', 'if', 'so', 'still', 'then', 'thus', 'in contrast', 'in fact', 'such as', 'as a result', 'on the contrary']
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance in Part of Speech:
Nouns: 0.272727272727 0.261695866417 104% => OK
Verbs: 0.163636363636 0.158904122519 103% => OK
Adjectives: 0.0969696969697 0.0723426182421 134% => OK
Adverbs: 0.0454545454545 0.0435111971325 104% => OK
Pronouns: 0.0151515151515 0.0277247811725 55% => OK
Prepositions: 0.133333333333 0.128828473217 103% => OK
Participles: 0.0454545454545 0.0370669169778 123% => OK
Conjunctions: 2.36438410053 2.5805825403 92% => OK
Infinitives: 0.030303030303 0.0208969081088 145% => OK
Particles: 0.00606060606061 0.00154638098197 392% => OK
Determiners: 0.139393939394 0.128158765124 109% => OK
Modal_auxiliary: 0.0 0.0158828679856 0% => OK
WH_determiners: 0.0181818181818 0.0114777025283 158% => OK
Vocabulary words and sentences:
No of characters: 1809.0 1645.83664459 110% => OK
No of words: 310.0 271.125827815 114% => OK
Chars per words: 5.83548387097 6.08160592843 96% => OK
Fourth root words length: 4.19604776685 4.04852973271 104% => OK
words length more than 5 chars: 0.383870967742 0.374372842146 103% => OK
words length more than 6 chars: 0.254838709677 0.287516216867 89% => OK
words length more than 7 chars: 0.138709677419 0.187439937562 74% => OK
words length more than 8 chars: 0.0677419354839 0.113142543107 60% => OK
Word Length SD: 2.36438410053 2.5805825403 92% => OK
Unique words: 150.0 145.348785872 103% => OK
Unique words percentage: 0.483870967742 0.539623497131 90% => More unique words wanted or less content wanted.
Word variations: 48.1434552253 53.8517498576 89% => OK
How many sentences: 12.0 13.0529801325 92% => OK
Sentence length: 25.8333333333 21.7502111507 119% => OK
Sentence length SD: 47.8808561837 49.3711431718 97% => OK
Chars per sentence: 150.75 132.220823453 114% => OK
Words per sentence: 25.8333333333 21.7502111507 119% => OK
Discourse Markers: 0.916666666667 0.878197800319 104% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 3.39072847682 0% => OK
Readability: 51.3172043011 50.5018328374 102% => OK
Elegance: 2.01351351351 1.90840788429 106% => OK
Coherence and Cohesion:
Essay topic to essay body coherence: 0.286836823543 0.549887131256 52% => OK
Sentence sentence coherence: 0.180187854024 0.142949733639 126% => OK
Sentence sentence coherence SD: 0.0782612453696 0.0787303798458 99% => OK
Sentence paragraph coherence: 0.697237497848 0.631733273073 110% => OK
Sentence paragraph coherence SD: 0.123128654383 0.139662658121 88% => OK
Sentence topic coherence: 0.16053362628 0.266732575781 60% => OK
Sentence topic coherence SD: 0.0517901830136 0.103435571967 50% => OK
Paragraph paragraph coherence: 0.498200834454 0.414875509568 120% => OK
Paragraph paragraph coherence SD: 0.0241832395309 0.0530846634433 46% => OK
Paragraph topic coherence: 0.221505613451 0.40443939384 55% => OK
Paragraph topic coherence SD: 0.0218885662988 0.0528353158467 41% => The ideas may be duplicated in paragraphs.
Task Achievement:
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 4.0 4.26048565121 94% => OK
Positive topic words: 2.0 3.49668874172 57% => OK
Negative topic words: 5.0 3.62251655629 138% => OK
Neutral topic words: 4.0 3.1766004415 126% => OK
Total topic words: 11.0 10.2958057395 107% => OK
What are sentences with positive/Negative/neutral sentiment?
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Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 Out of 30
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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.