The second book Dune Messiah doesn’t go into much of the science of the universe , but Children of Dune and God Emperor of Dune and the other two go into more detail on the ecology because it cycles through the desertification of Dune through the regular climate back to desert, again. Herbert ties to give the details of the changes from one climate to another and back. I read, somewhere, that Herbert posited and imagined that goats were the ecological template for the worms.