Douglas-fir(Pseudotsuga menziesii(Mirb.)Franco)is an important exotic tree species that was planted across a large part of Europe during the last century.In both experimental trials and conventional forest plantations...Douglas-fir(Pseudotsuga menziesii(Mirb.)Franco)is an important exotic tree species that was planted across a large part of Europe during the last century.In both experimental trials and conventional forest plantations,the trees grow at a high rate and produce high-quality timber.The present study investigated climate-growth relationships of Douglas-fi r at two Italian sites that contrast in climate:a Mediterranean area in southern Italy(Mercurella site)and a cooler,moister site in the northern Apennines without summer aridity(Acquerino).The relationship between tree-ring chronologies and monthly climatic variables was evaluated by a moving average and correlation analysis.Results showed that the minimum temperature in February and in March play a key role for Douglas-fi r at both sites,with a positive eff ect on growth.At the northern site,it is also highly sensitive to late summer temperatures(negative correlation)and spring–summer precipitation(positive correlation).Growth rates in southern latitudes were high even in Europe and in the Mediterranean environment,with low sensitivity to climatic fl uctuation.On the basis of our results,further common garden experiments should test adaptation and the interaction between genetics and environment of second-or third-generation seeds from old stands across Europe such as done by the old International Union of Forest Research Organizations(IUFRO)or the European Douglasfi r Improvement Research Cooperative(EUDIREC)experimentation programmes.展开更多
基金Besides of the fi nancial support from the RGVFAO Project,Cristiano Castaldi has received the support by University of Tuscia(Italy)as Ph.D.student.The authors thank an anonymous reviewer for helpful suggestions on an earlier draft of this paper.
文摘Douglas-fir(Pseudotsuga menziesii(Mirb.)Franco)is an important exotic tree species that was planted across a large part of Europe during the last century.In both experimental trials and conventional forest plantations,the trees grow at a high rate and produce high-quality timber.The present study investigated climate-growth relationships of Douglas-fi r at two Italian sites that contrast in climate:a Mediterranean area in southern Italy(Mercurella site)and a cooler,moister site in the northern Apennines without summer aridity(Acquerino).The relationship between tree-ring chronologies and monthly climatic variables was evaluated by a moving average and correlation analysis.Results showed that the minimum temperature in February and in March play a key role for Douglas-fi r at both sites,with a positive eff ect on growth.At the northern site,it is also highly sensitive to late summer temperatures(negative correlation)and spring–summer precipitation(positive correlation).Growth rates in southern latitudes were high even in Europe and in the Mediterranean environment,with low sensitivity to climatic fl uctuation.On the basis of our results,further common garden experiments should test adaptation and the interaction between genetics and environment of second-or third-generation seeds from old stands across Europe such as done by the old International Union of Forest Research Organizations(IUFRO)or the European Douglasfi r Improvement Research Cooperative(EUDIREC)experimentation programmes.
