Ist at the end of the word means the study of so we have a tree civilization studied by arborists. The tree will be cut and used by mankind. An arborist however, is concerned with keeping trees around. Tree preservation is his or her game. An arborist would be concerned about tree planting, the care of an aging giant tree, helpful and harmful insects, bacteria and fungus that try to break the tree down, proper pruning to prolong a tree's health, fertilization, protection against the most harmful opponent, mankind, and a legion of other subjects.
Arboriculture is a new science.
Up until recently, mankind has been mostly concerned about harvesting trees or their fruits. Building and fuel needs were and continue to be great. The tree civilization has decreased to such an extent that mankind is beginning to miss those woody pals that were once so common. The fact that our air quality is decreasing along with tree decline pushes us more into the corner to where tree preservation is not a mere luxury. It's tied directly to the survival of mankind.