Question

An ecologist wants to know if diversity in a forest system is likely to decrease when an invasive species is introduced. This invasive species is a fast-growing annual plant that grows on oak trees and kills them. The invasive species can only survive on living oak trees. The ecologist has the original model from this lab and another version of the model which includes transitions that involve the invasive species. To answer the research question, the ecologist should compare species diversity generated by the original model to diversity generated by which model described below?
1) A model in which oak has a positive transition rate to the invasive and the invasive has a positive transition to grass.
2) A model in which oak has a positive transition rate to the invasive and the invasive has a positive transition to oak.
3) A model in which the invasive has a positive transition rate to oak and oak has a positive transition to grass.

Answer 1

Answer:

A model in which oak has a positive transition rate to the invasive and the invasive has a positive transition to oak.

Explanation:

An invasive species is the one which is non-native to the given ecosystem. Its growth hampers balanced ecological parameters and disturbs food web as well as normal flora.The overall effect of invasive species is decreasing biodiversity in selected ecosystem. As the ecologist needs to understand effect of this invasive species, firstly it is important to understand the transition of oak tress to invasive form. The transition rate is one of the deciding factor to introduce diversity in ecosystem. Also if the invasive form has the ability to revert back to original oak tress it would restore the original ecosystem. Thus a model in which oak has a positive transition rate to invasive and the invasive has a position transition to oak can be selected for the analysis. In other models, the final trnasition to grass would introduce lot of biodiversity in selected ecosystem which would be of little importance to understand transition rate.