>Axel Lindahl’s picture of Engabreen from 1889 shows the foot of the glacier, where there was only ice, glacial gravel, water and bare mountainsides in a seemingly cold and hostile landscape. Now, more than 120 years later, the valley has become far more fertile. Birch forest, shore meadows, willow thickets and marshland have established themselves, while the glacier arm has retreated far back up the mountainside.
"Imagine a time machine that could take you back 150 years. Open the door and look out at the slopes of Vermont, the Green Mountain State. In 1850, the slopes would be anything but green. Most would be barren, stripped of their trees, and trampled by grazing sheep."
Global changes aside, it takes awhile to form soils that will support plant life. Near the foot of a retreating glacier, you'll always have till and moraines. If they've been recently exposed, they'll always be bare. It takes a few decades for forests, etc to get established.
Deforestation was happening in the 1600s and 1700s and required the stopping of many saw mills.
I just say this because humanity really did horrible environmental things throughout our history. For example the ceders of Lebanon being completly cut down by 800 BC and the deforestation of Israel during the crusades which never came back.