Hello all: I would like to test whether there are treatment effects on decomposition rate, and I would like to inquire about the best, most appropriate means using R.
I have plant decomposition data that is generally considered to follow an exponential decay model as follows: Wt = Wi * exp(-k * t) Where Wt and Wi are the weights of the plant material at time t and 0, respectively. k is a constant describing decomposition rate and is usually reported in the literature. Is it possible to fit a non-linear model as above and test for effects of two, independent, treatment factors + the interaction? I have used nls() to fit the above model for each treatment and approximate k, but I would like to examine treatment effects on these fits as I might using glm(). If I can get passed this hurdle, I may also inquire about adding a random effect as well. If it helps, I can post a subset of data. Thanks for any help. - Justin Montemarano Graduate Student Kent State University - Biological Sciences http://www.montegraphia.com [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
