I narrowed down my study area to a patch of trees within the small canyon that are all within 30m from each other. Within the study area, I noticed that in addition to the conifer trees, there were also several dead, fallen over trees and some tree stumps. For my project, I am interested in insect variety and abundance in relation to dead and living trees. The study locations will be a two tree stumps, two fallen over trees, and two living trees. Having two of each kind of tree will give more accurate data in case there is an outlier. There appeared to be many insects such as ants and beetles on the tree stump, so my hypothesis is that insects thrive more living inside of dead trees rather than living trees. For this study, the response variable is the variety and abundance of insects and the explanatory variable is the condition of the trees. The response variable is continuous because it is a measure of number of insect species and abundance while the explanatory variable is categorical because it is one of the three tree conditions.
Study area:
You need more than 2 replicates in each group. Five is a good minimum number where you might start to be able to talk about differences between groups and the more samples you have the better. Your response variable you need to be a bit more specific. Do you have 2 response variables – the total number of insects AND the number of different species??
Also, what is your hypothesis…what is the piece and what is the pattern and what is the underlying ecological process you think is driving that pattern. Make sure you spend some time on the hypothesis and experimental design tutorials in Moodle. The time you spend now will pay off later.