Is the felling of trees and bushes which grow on private property subject to permission?

Yes, you need permission to fell all woody plants growing outside of the forest regardless of the ownership situation. On private property (land which is owned by private individuals) you can only fell trees with a circumference of less than 80 cm at 130 cm above ground level and contiguous stands of bushes of less than 40m2 without permission. This is valid for plots of land which the private individual utilises, and in the case that we are not talking about significant landscape elements, tree monuments, or in the case of specially protected plant species!