Make the given paragraph clearer:
It hindered growth and weakened the vitality of entire stands of trees. Early on resin collecting was restricted to stands that were not easily felled and transported i.e. those that were a long way from rivers.
It hindered growth and weakened the vitality of entire stands of trees. As a result, early on resin collecting was restricted to stands that were not easily felled and transported i.e. those that were a long way from rivers.