I have growth rate data over 10 years which I would like to analyze against few variables like rain, temperature and soil nitrogen. But the growth rates are negative as well as positive. What are the possible ways I could analyze the data? Should I log transform the growth rate to make sure all data is positive? I understand that I cannot run a GLM with negative dependent variable. I would appreciate the help.
gr<-c(0.01,0.03,-0.10,0.01,0.07,-0.03,0.02,0.50,-0.02,-0.01)
rain<-c(200,250,450,310,120,230,440,130,220,320)
temp<-c(25,20,17,19,20,21,15,18,21,19)
nitro<-c(0.08,0.10,0.11,0.06,0.11,0.13,0.09,0.10,0.07,0.13)