Insects and pests can damage birch tree's bark and leaves. Trees, like humans, can get sick. There are some diseases, like stem cankers, that can kill a whole birch tree!
The biggest threat to birch trees is climate change. The changing climate has made weather more severe. When temperatures are higher than usual in the summer, birch trees can be dehydrated. When there is more snowfall, the heavy weight can break the birch tree's branches. These make the trees an easier target for disease and insect invasions.
The good news is that Finland is very good at forestry. They make sure that they grow more trees than they cut down. Finns are also researching ways to use trees to solve some of these problems.
