There are about 3 trillion trees on Earth, or roughly 400 per capita, according to estimates published in Science. Nearly half of the trees stand in tropical or subtropical forests. In a typical year, 15 billion trees are cut down. At the start of human civilization, the number of trees was approximately twice as high as today.
A few miles east of today’s Belgrade lies a Vinča settlement that dates back to 5000 BC. The Vinča civilization relied on fishing, farming and mining (copper); the Vinča people built houses along streets; and they exchanged goods. They also used an early form of proto-writing (sources: Belgrade tourism site, Wikipedia).
Alex Whitaker writes on his site Ancient Wisdom:
In 1908, the largest prehistoric Neolithic settlement in Europe was discovered in the village of Vinca, just a few miles from the Serbian capital Belgrade, on the shores of the Danube. Vinca was excavated between 1918 and 1934 and was revealed as a civilisation in its own right. Indeed, as early as the 6th millennium BC, three millennia before Dynastic Egypt, the Vinca culture was already a fully fledged civilisation. A typical town consisted of houses with complex architectural layouts and several rooms, built of wood that was covered in mud. The houses sat along streets, thus making Vinca the first urban settlement in Europe, but being far older than the cities of Mesopotamia and Egypt. And the town of Vinca itself was just one of several metropolises, with others at Divostin, Potporanj, Selevac, Plocnik and Predionica.