Adaptation of Ash (Fraxinus excelsior) to Climate Change

Summary Description:

The aim of this part-time PhD is to test the adaptability of native ash from a range of UK locations to the predicted climate in 2080.
The specific objectives are to:

• identify provenances of ash that may be closely matched to the future climate and to test them in the current climate through a series of reciprocal transplant experiments
• determine the phenology of ash provenances in relation to their suitability for growing in the predicted climate of 2080
• determine the stratification (cold pretreatment) requirements of the seed of ash provenances
• determine levels and effects of outbreeding depression

Project Outcomes:

Climate-matching data were used to identify ten provenances and five sites for a series of reciprocal transplant experiments along a latitudinal gradient from northern Scotland to the Pyrenees.  Survival and growth have been measured over three years (2009-2011).  So far there is very little indication that local provenances grow better than non-local ones, but monitoring of the experiments will continue.

It has been shown that provenances have different chilling requirements for both bud burst and seed germination, with northerly provenances requiring a longer period of chilling than southerly ones.  If winters in the UK become warmer, as predicted by climate change models, bud burst of trees in native populations of ash may be delayed and natural regeneration may be less successful