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 presents three hypotheses to explain the decline of a species of tree, named yellow cedar. However, the lecturer categorically refutes all the hypotheses, citing that they are not only inadequate but also problematic.
Firstly, the reading states that one of the hypotheses is that a particular type of insects is in charge of the yellow cedar decline. Conversely, the lecturer opposes this point by saying that these types of trees are more resistant to insects. he mentions leaves and barks of these trees and how resistant they are. Moreover, the professor explains that there is poisonous chemical substance under the bark of yellow cedars that protect them against insects. In addition, he states that insects attack the yellow cedar trees which are already damaged. Overall, insects cannot be the fundamental cause of the yellow cedar decline.
Secondly, the article avers that another hypothesis is that brown bears play a role in the decline. In contrast, the speaker contends that the decline has been occurring in both the mainland and island, and while there is no bear on the island, the populations of the yellow cedar are still declining on the island, as well. Therefore, again, brown bears cannot be responsible for the reduction.
Finally, the writer argues that the third hypothesis can be about climate change. On the contrary, the professor puts forth that although according to the hypothesis, the trees in higher elevation should be more affected by climate changes (i.e., it is more likely that their roots expose to the cold weather), the decline is more severe in lower and warmer origins. As a result, it is not probable that the sensitivity of growing roots kills the trees.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2020-01-24 | supergirl20 | 40 | view |
| 2020-01-11 | Raziya | 80 | view |
| 2020-01-05 | S M Naimul Mamun | 70 | view |
| 2019-11-27 | shingwa | 80 | view |
| 2019-11-21 | omarsamiiir | 73 | view |
Grammar and spelling errors:
Line 5, column 1, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...y inadequate but also problematic. Firstly, the reading states that on...
^^^^^^^
Line 9, column 251, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: He
...of trees are more resistant to insects. he mentions leaves and barks of these tree...
^^
Line 13, column 1, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...cause of the yellow cedar decline. Secondly, the article avers that an...
^^^^^^^
Line 21, column 1, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
... be responsible for the reduction. Finally, the writer argues that the...
^^^^^^^
Transition Words or Phrases used:
also, but, conversely, finally, first, firstly, however, moreover, second, secondly, so, still, therefore, third, well, while, in addition, in contrast, as a result, on the contrary
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 18.0 10.4613686534 172% => OK
Auxiliary verbs: 4.0 5.04856512141 79% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 15.0 12.0772626932 124% => OK
Pronoun: 26.0 22.412803532 116% => OK
Preposition: 30.0 30.3222958057 99% => OK
Nominalization: 4.0 5.01324503311 80% => OK
Performance on vocabulary words:
No of characters: 1466.0 1373.03311258 107% => OK
No of words: 282.0 270.72406181 104% => OK
Chars per words: 5.19858156028 5.08290768461 102% => OK
Fourth root words length: 4.09790868904 4.04702891845 101% => OK
Word Length SD: 2.56958145535 2.5805825403 100% => OK
Unique words: 153.0 145.348785872 105% => OK
Unique words percentage: 0.542553191489 0.540411800872 100% => OK
syllable_count: 446.4 419.366225166 106% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 4.0 3.25607064018 123% => OK
Article: 12.0 8.23620309051 146% => OK
Subordination: 2.0 1.25165562914 160% => OK
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 3.0 2.5761589404 116% => OK
Performance on sentences:
How many sentences: 14.0 13.0662251656 107% => OK
Sentence length: 20.0 21.2450331126 94% => OK
Sentence length SD: 59.0453388577 49.2860985944 120% => OK
Chars per sentence: 104.714285714 110.228320801 95% => OK
Words per sentence: 20.1428571429 21.698381199 93% => OK
Discourse Markers: 12.9285714286 7.06452816374 183% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 4.0 4.19205298013 95% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 8.0 4.45695364238 179% => OK
Sentences with neutral sentiment: 5.0 4.27373068433 117% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.258954058841 0.272083759551 95% => OK
Sentence topic coherence: 0.0802605800555 0.0996497079465 81% => OK
Sentence topic coherence SD: 0.0597964741822 0.0662205650399 90% => OK
Paragraph topic coherence: 0.136398887288 0.162205337803 84% => OK
Paragraph topic coherence SD: 0.0271276312187 0.0443174109184 61% => OK
Essay readability:
automated_readability_index: 13.1 13.3589403974 98% => OK
flesch_reading_ease: 51.18 53.8541721854 95% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 11.1 11.0289183223 101% => OK
coleman_liau_index: 12.88 12.2367328918 105% => OK
dale_chall_readability_score: 8.88 8.42419426049 105% => OK
difficult_words: 76.0 63.6247240618 119% => OK
linsear_write_formula: 8.5 10.7273730684 79% => OK
gunning_fog: 10.0 10.498013245 95% => OK
text_standard: 9.0 11.2008830022 80% => OK
What are above readability scores?
---------------------
Rates: 65.0 out of 100
Scores by essay e-grader: 19.5 Out of 30
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Note: 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.