Thank you very much, I tried using install.packages("gbm") and it worked.
My other query is, I would like to use the gbm package and regression trees packages to model and predict land cover change (y) using predictor variables (x) such as distance to road, soil type, elevation, average rainfall and fire frequencies. Do you have any R scripts and suggestions as to how I can succesfully create this model and predict the land cover?
Thanks
Edward