It is a common perception that the old forests of Europe were all large, deep and dark, and that they were made up of old trees. Naturally this is not the case. Many places in Europe there is not enough soil for trees to grow large no matter how old the trees are, and just like today forest fires caused by lightning every now and then burned down a few forests. After every Ice Age ended the forests had to start anew, so to speak, and crawl slowly northwards again, over the open landscape left by the retracting glaciers. The plains were eventually replaced by forests most places, but everything was alive, so nothing remained static for a very long time. Some types of trees took over - "conquered" - the forests and then after a while a whole new type of forest came about, possibly and probably even with a different fauna.
Today most (79%) of the trees in Norway are coniferous, but even in the Viking Age things were different; oak forests dominated the entire coastline. Then came the XVth
century, and the oak forests of Norway, and indeed of all of Europe, suffered greatly and most places disappeared altogether, because the Christianized nations of Europe greedily set out to colonize and Christianize the rest of the world - in wooden ships. The coniferous forests took over in Scandinavia.
Although most trees even in the Ancient World were not as old as we would like them to be there were still many very old trees - and a few very old forests too - and it is no wonder why they were seen as sacred and as manifestations of the deities.
Today we still encounter some of these very old trees, if we move about in the wilderness, and some places they are more common than other places, and when we do they still impress us, please us and make us feel something spiritual. Something Divine!
Some might see light, love and hope when kneeling in front of a crude representation of some crucified criminal foreigner, bleeding and dying slowly on a Roman execution device, but I have to say I prefer the sight of the sacred objects of Ancient Europe.
Man is capable of creating magnificent beauty in our world, but certainly so is nature on its own.