Simplify the following text for a Grade 7 native English-speaking person.
Original: The winters are mild at low altitude but become snowier and colder with higher elevation , mountains may have up to 6 months of snow and naturally the area would be a vast birch , pine and montane shrub forest , such as those surviving in glen affric .
Simplified: Mountains may have up to 6 months of snow . Naturally the area would be a vast birch , pine and montane shrub forest , such as those surviving in Glen Affric .