You are employed as a consultant at a large paper company, because the company is concerned about defoliation caused by insects in its poplar plantations. Insect damage can have severe effects on tree health, and can even cause tree mortality in large areas of forest. The paper company is considering altering the way it grows trees from a one-species plantation to more of a natural multi-species forest setting, in response to the insect damage. After consulting with a forest entomologist, you find out that the insect most prevalent in the poplar plantations is the poplar tentmaker ( Icthyura inclusa ), but you also find the cottonwood leaf beetle ( Chrysomela scripta ) present. Most trees can reproduce both vegetatively (asexual clones) and sexually; poplar trees are known to produce huge tracts of clonal shoots, and a single tree can produce hundreds of thousands of seeds per year.

Given that there can be both sexual and asexual reproduction in poplar trees, you decide that it would be a good idea to test the changing-environment hypothesis for this site, in comparison to a nearby natural forest that has a mixture of poplar, red oak, and black cherry. You collect data at ten 10-m2 plots at each site (plantation and forest) based on two factors: percentage of infected trees and percentage of trees that are clonal versus sexually reproduced. The data you collect are provided in the chart below.

	Plantation Site		Forest Site
	Percent infected trees	Percent clonal	Percent infected trees	Percent clonal
Mean	24.6	80.2	12.1	49.8
Deviation) SD (Standard	3.27	4.52	3.90	4.18
samples) N (Number of	10	10	10	10
Error) SE (Standard	1.03	1.43	1.23	1.32

a) In your own words, describe the changing-environment hypothesis (in reference to sexual vs. asexual reproduction, was discussed in the lecture video or you can look it up in the textbook or internet).

b) Do the data above support or refute the changing-environment hypothesis? What would you recommend to the paper company?

Answer rating: 100% (QA)

a An associated statistic that is also relevant is the standard deviation because it is in the same ... View the full answer