Sensitivity of French temperate coniferous forests to climate variability and extreme events (Abies alba,Picea abiesandPinus sylvestris)

Abstract

Questions: (1) How do extreme climatic events and climate variability influence radial growth of conifers (silver fir, Norway spruce, Scots pine)? (2) How do elevation and soil water capacity (SWC) modulate sensitivity to climate? Location: The sampled conifer stands are in France, in western lowland and mountain forests, at elevations from 400 to 1700 m, and an SWC from 50 to 190 mm. Methods: We established stand chronologies for total ring width, earlywood and latewood width for the 33 studied stands (985 trees in total). Responses to climate were analysed using pointer years and bootstrapped response functions. Principal component analysis was applied to pointer years and response function coefficients in order to elucidate the ecological structure of the studied stands. Results: Extreme winter frosts are responsible for greater growth reductions in silver fir than in Norway spruce, especially at the upper elevation, while Scots pine was the least sensitive species. Exceptional spring droughts caused a notable growth decrease, especially when local conditions were dry (altitude<1000 m and SWC<100 mm for silver fir, western lowlands for Scots pine). Earlywood of silver fir depended on previous September and November and current‐year February temperature, after which current June and July water supply influenced latewood. Earlywood of Norway spruce was influenced by previous September temperature, after which current spring and summer droughts influenced both ring components. In Scots pine, earlywood and latewood depended on the current summer water balance. Local conditions mainly modulated latewood formation. Conclusions: If the climate becomes drier, low‐elevation dry stands or trees growing in western lowlands may face problems, as their growth is highly dependent on soil moisture availability.

Growth patterns of Scots pine (Pinus sylvestris L.) under the current regional pollution load in Lithuania

“…However, in our study tree growth increment was positively correlated to warming in the dormant period. Evergreen conifers can photosynthesize all year around, and warm winters can increase the synthesis and storage of carbohydrates to be used in the next growing season (Lebourgeois et al 2010). Indeed, this promoted the earlywood formation in spring when combined with abundant precipitation, which increases the water availability in the soil.…”

“…Soil water shortage is a major limiting factor for tree growth (Michelot et al 2012), making trees growing on sites with lower water availability more sensitive to climatic variations (Lebourgeois et al 2010). The lack of precipitation may be considered a limiting factor for tree growth at seaside in Lithuania, where forest stands are located on sandy soils.…”

Xylogenesis: Coniferous Trees of Temperate Forests Are Listening to the Climate Tale during the Growing Season But Only Remember the Last Words!

“…Moreover, the relationships were species specific because of slightly different levels in the wall deposition rate and different climatic sensitivities between species. Notably, the higher slope was observed in silver fir, which is known to have the highest climatic sensitivity of the three species, whereas the lowest slope was observed in Scots pine, which is the least sensitive species (Lebourgeois et al, 2010).…”

The effect of climatic factors on height increment of Scots pine in sites differing by continentality in Latvia

“…The linkage of HI to nutrient reserves also seems to be influenced by the effect of precipitation in the previous August (Figs. 3, 4 B) which might be explained by decreased assimilation due to water deficit (Pallardy 2008), as observed for radial growth of Scots pine in Central Europe (Oberhuber et al 1998;Lebourgeois 2010). The availability of water during shoot elongation also has affected HI as suggested by significant correlation with precipitation in the current May and June (Fig.…”