Karl Foord, UMN Extension Educator
The arborist pursued two strategies, crown thinning (Figure 1) and crown raising (Figure 2) both taken from the USDA Forest Service publication, "How to Prune Trees".
The before and after pictures show that some lower limbs were removed and how the center of the tree was opened up, reducing wind resistance and the number of limbs available for ice accumulation.
The trees in the picture were planted in 2000. I have another set of Autumn Blaze maples planting in 1997. What is the value of the trees? If they are damaged in a storm, how much time has been lost? I would rather hedge my bets and see that they are properly pruned. The last photo shows one of the trees planted in 1997.