What Are Some Examples of Human-Environment Interaction in Rome, Italy?

The expansion of the Roman Empire was from about 60 B.C. till the Empire's dissolution in 476 A.D., and many of the innovations that Romans brought to other countries were fueled in part by dwindling resources in the area of Rome itself. As the people of Rome used up firewood, and grains became scarcer due to a rising population, it was the human-environment interaction which led to the political and military decisions to conquer other lands.