Journal Article climate change Research Support, Non-U.S. Gov't phenology Betula pendula FORBIO Fagus sylvatica Quercus robur autumn senescence autumnal phenology biodiversity breakpoints budburst canopy dynamics carryover effect of leaf unfolding common garden cooling degree days forest ecology leaf coloration and fall leaf phenology leaf senescence leaf senescence model leaf-out microclimate model evaluation mortality open-top chamber photoperiod productivity seasonal warming