A ‘State of the World’ report warns that a third of the world’s wild tree species are threatened with extinction. Agriculture and logging are the main culprits. They were in the ancient world too.
It is hard to overestimate the importance of trees for past societies: they were the only source of fuel for heating, cooking, potting, including tiles and bricks, and smelting (coal came into play only from the 16th century), and of timber for building. The emergence of palace states and the growth of trade during the Bronze Age from c. 3000 bc — bronze, made by smelting tin and copper, was far more durable than copper — increased its use dramatically. During the classical period large navies made heavy demands on timber supplies; so did Roman armies with camps, siege works, bridge and road-building, forest clearances to deny the enemy cover, as did the vast urban centres, with building, rebuilding after fires and fuel (those huge bath complexes!).
Further, clearing trees, first from the plains, then from the lower slopes of the mountains, also cleared the ground for farming, essential if the population was to grow. In 146 bc Rome defeated Carthage and made North Africa (Tunisia) a province. The land was cleared and made cultivable: by c. ad 100 it was providing Rome, a city of a million people, with two thirds of its grain.
In ad 111 Romans legislated that anyone who cleared public land for cultivation (up to 20 acres) legally owned it. However, while we hear of replanting of olives and trees for estates, sources are silent on building timber. The main constraint on logging was location: proximity to sea or river was essential if the huge beams Romans used for building basilicas and temples (we know of one 100ft long) were to be transported any distance.
So what were the long-term results? Both Greece and Italy suffered some depletion, but not much. The big losses were the famous cedars of Lebanon: ancient Middle Eastern states so depleted them that in ad 138 Hadrian declared them his property. But it made little difference. Only 17 square kilometres now remain.