Journal Article climate change Ellenberg indicator values Europe European forests Picea abies Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Soil atmospheric nitrogen deposition bark beetles carbon sink climate change mitigation dendroecology disturbance legacies ecosystem services empirical disturbance data fire forest management forest natural disturbances forestREplot historical ecology management portfolios overstory buffering primary forest regional scale robust optimization substitution effects susceptibility temporal resurvey data