Model analysis of temperature impact on the Norway spruce provenance specific bud burst and associated risk of frost damage

• Temperature sums required for bud burst can be used to predict risk of spring frost. Provenances with earlier timing display a higher frost damage. Increased events after is projected in warmer climate. A link between growth rhythm provenances and seed orchards needed. The annual cycle boreal trees synchronized seasonal changes photoperiod temperature. climate lead an increased damage caused by temperature backlashes. In this study we analysed site- provenance specific responses interannual variation temperature, using data from 18 Swedish East-European Norway spruce ( Picea abies ), grown three different sites southern Sweden. sum requirements burst, estimated the trials, were correlated place origin, terms latitudinal longitudinal gradients. Frost had significant effect on tree height development. Earlier was linked damage, one being more prone than other two. parametrize model timing, which then together ensemble gridded (RCP8.5) assess change impact associated respect, simulated occurrence periods 2021–2050 2071–2100 compared 1989–2018. response climate, total number Sweden will decrease, while increase due timing. assessments under selection sources forestry. selecting suitable provenances, knowledge local conditions importance, as may differ conditions. comparison logger ten indicated that good proxy daily mean temperatures, but minimum temperatures tended underestimate events, particular at measurements 0.5 m above ground representing newly established seedlings.