Timing and Order of Extreme Drought and Wetness Determine Bioclimatic Sensitivity of Tree Growth

Tree resistance to extreme droughts and post-drought recovery are sensitive the drought timing. However, how bioclimatic sensitivity of tree growth may vary with timing order wetness is still poorly understood. Here, we quantified in period 1951–2013 under different seasonal drought/wetness regimes over extra-tropical Northern Hemisphere, using 1,032 ring chronologies from 121 gymnosperm angiosperm species. We found a negative asymmetry droughts. With drought, arid temperate dry regions more negatively impacted by pre-growing-season (PGS) Clade-wise, angiosperms PGS water availability, gymnosperms legacy effects preceding conditions humid regions. Our finding divergent underscores contrasting trends forest responses across ecoregions functional groups climate.