Marcescent oak leaves

Even in today's blizzard with snow and 35+ mph wind gusts, the oak leaves are still hanging on. Withered and dry they are, but they will not fall off till spring when the spring buds push them off. Marcescent leaves, leaves that hang on even though they are dead, are a characteristic of younger oak tress. This particular tree was planted about 20 years ago. That is young for an oak tree. Another characteristic of marcescent leaves is that they occur on the lower branches as exemplified here. There are various theories about why certain trees, mostly oak, hornbeams, and beech do this and but not a lot of research has been done.