TPO 38 https zabanexam com toefl sec 4

The reading passage is talking about protecting the western forests of US from a fungus called P. ramorum that causes serious damage to oak trees and shows three methods to overcome this problem. The speaker in the lecture goes against the ideas and refutes each method mentioned in the passage.

First, the passage assumes that the trees can be protected by preventing human-assisted spread of the fungus spores through enforcing the hikers to wash their shoes and installing new bike scrubbers on bicycle trails. The speaker, on the other hand, reckons that this way has limitations and ineffective in protection as the studies showed that spores are transferred mainly by streams and rain water more than the hikers which is hard to control.

Secondly, the reading suggests using fungicides to kill the fungus. The lecturer thinks that although this method can be effective only for few trees, it is not practical for the whole forest that contains thousands of trees as the fungicide needs to be directly injected in the trees. It will be very expensive and impractical as the effect of the fungicide does not remain so long and the injection should be repeated every few months.

Lastly, the third method the passage shows is to cut and burn the infected trees as well as the surrounding vegetation that may be infected even if they look healthy. On the contrary, the speaker dissents from this idea as it is not logic to sacrifice with the healthy plants to stop a disease. He also states that the species of the trees in this area of US are rare and can not be returned again, besides, the ecological damage that will occur overrides the benefits.