What Stat test(s) is best for paired samples that also accounts for change overtime

#1
Hello,

I am new to this forum and a bit of a stat novice. I am a biogeochemical Research Technician studying environmental gas production.

We are performing a study on gases produced from soil over several weeks. We have an experimental and control treatment with four plots in each treatment. We take multiple samples from each plot over the course of a single sample day. I am trying to determine a robust statistical method to evaluate these data. There is a high degree of variability of gas concentration between dates and between the experimental plots. I need a method that quantifies the variability between plots and evaluates the differences between experimental and control plots.

I was intending to use a variation on the traditional anova to look at difference between plots and treatments. I considered a repeated measures ANOVA because my understanding is that this is the ANOVA version of a paired T-test and I would be able to pair samples by date then perform a second statistical analysis such as Fisher's LSD to look at the difference in mean concentration over time.

Because I am a stat novice I am uncertain of the pitfalls of these tests and their respective assumptions. I would greatly appreciate any advice and will provide sample data if needed. We are looking at the concentration of over two dozen gases so this is only the beginning approach which I may need to modify for each gas concentration we analyze. I am performing analysis in R.