Differing growth responses to climatic variations and soil water deficits of Fagus sylvatica, Quercus petraea and Pinus sylvestris in a temperate forest.

摘要

In addition to global warming, the frequency and the intensity of droughts will probably increase in central and southern Europe. Resulting climate changes and soil water deficits could alter tree growth, according to sensitivity of each species. The aim of this study was to compare the growth response of three European species (Fagus sylvatica, Quercus petraea and Pinus sylvestris) to climatic variations and soil water deficits in the same temperate forest. Three mature stands per species were sampled to obtain earlywood, latewood and total ring chronologies from 1960 to 2007. Climate-growth relationships were established by bootstrapped correlations and response function analysis. Monthly bioclimatic regressors were simulated by a physiological water balance model that used daily climatic data and stand parameters to estimate soil water deficits. Our results highlighted a common sensitivity to precipitation from May to July for the dominant tree growth of the three species but also differences in the species vulnerability to climate and soil water deficits. Beech was the most sensitive species to the climatic conditions of the current growing season. Beech growth was positively correlated with precipitation from May to July and negatively with maximal temperatures in June and July. Oak growth was negatively correlated with minimal temperatures in the previous August and September and positively with precipitation in the previous October and December during pointer years. This led to long-term consequences for growth, probably due to carbon reserve depletion. Pine growth was positively influenced by warm December but was also vulnerable to maximal temperatures and soil water deficits from June to August. The climate in August only influenced the pine growth probably because the growing season of pine was longer than that of the deciduous species. For both oak and pine, latewood was the component that was most sensitive to climatic variations and soil water deficits. According to the study findings, an increase in the frequency and the intensity of droughts could affect the three species. Maximum summer temperatures could have negative impacts for beech and pine growth. Dry and warm autumns could lead to long-term consequences and decrease the oak growth.