Comparing the intra-annual wood formation of three European species (Fagus sylvatica, Quercus petraea and Pinus sylvestris) as related to leaf phenology and non-structural carbohydrate dynamics

Abstract

Monitoring cambial phenology and intra-annual growth dynamics is a useful approach for characterizing the tree growth response to climate change. However, there have been few reports concerning intra-annual wood formation in lowland temperate forests with high time resolution, especially for the comparison between deciduous and coniferous species. The main objective of this study was to determine how the timing, duration and rate of radial growth change between species as related to leaf phenology and the dynamics of non-structural carbohydrates (NSC) under the same climatic conditions. We studied two deciduous species, Fagus sylvatica L. and Quercus petraea (Matt.) Liebl., and an evergreen conifer, Pinus sylvestris L. During the 2009 growing season, we weekly monitored (i) the stem radial increment using dendrometers, (ii) the xylem growth using microcoring and (iii) the leaf phenology from direct observations of the tree crowns. The NSC content was also measured in the eight last rings of the stem cores in April, June and August 2009. The leaf phenology, NSC storage and intraannual growth were clearly different between species, highlighting their contrasting carbon allocation. Beech growth began just after budburst, with a maximal growth rate when the leaves were mature and variations in the NSC content were low. Thus, beech radial growth seemed highly dependent on leaf photosynthesis. For oak, earlywood quickly developed before budburst, which probably led to the starch decrease quantified in the stem from April to June. For pine, growth began before the needles unfolding and the lack of NSC decrease during the growing season suggested that the substrates for radial growth were new assimilates of the needles from the previous year. Only for oak, the pattern determined from the intraannual growth measured using microcoring differed from the pattern determined from dendrometer data. For all species, the ring width was significantly influenced by growth duration and not by growth rate, which differs from previous studies. The observed between-species difference at the intra-annual scale is key information for anticipating suitability of future species in temperate forests.

Temperate and boreal forest tree phenology: from organ-scale processes to terrestrial ecosystem models

“…These references document distinct patterns among tree functional types with regard to the relative onsets of cambium division and leaf appearance. In the majority of diffuse-porous trees, the onset of cambium division occurs simultaneously with or a few days after budburst (Suzuki et al 1996;Čufar et al 2008;Michelot et al 2012;Prislan et al 2013), though delays of several weeks have been observed in a number of species (e.g., as long as 8 weeks in Carpinus betulus; Delaporte (2010)). Ring-porous trees are relatively more vulnerable to freezing-induced embolism than diffuse-porous species (Cochard and Tyree 1990).…”

“…In certain ring-porous species (deciduous oaks), the onset of cambial division is the first step of spring resumption (Gričar 2010;González-González et al 2013), whereas in others (e.g., Fraxinus excelsior), overwintering vessels start to enlarge before budburst (SassKlaassen et al 2011) and cambial division is resumed after budburst (Frankenstein et al 2005). In conifers, the resumption of cambium activity generally occurs before budburst (Rossi et al 2009;Gruber et al 2010;Cuny et al 2012;Michelot et al 2012;Huang et al 2014).…”

Intra-annual radial growth of European beech – a case study in north easternmost stand in Europe

“…As demonstrated by Steppe & Lemeur (2004) and Michelot et al (2012), growth of both juvenile and mature beech trees was drought sensitive. Suffi cient water uptake ensures cell turgor pressure which is the main force providing cell expansion and division (Lockhart, 1967).…”

“…Earlier growth onset for DT can be explained by higher root competitiveness of dominant trees which are very competitive, ensuring better water absorption (Le Goff & Ottorini, 2001). During the observation period, cumulative changes of stem diameter formed a sawblade shaped curve with fl uctuations caused by daily variations of wood hydration (Steppe & Lemeur, 2004;Michelot et al, 2012). Pronounced leaps, corresponding to rain events and/or a decrease in VPD and air temperature, are distinguished as phases of increment.…”

“…Data on short term responses based on stem diameter variation (SDV) can be conveniently gathered by means of dendrometry. Several studies (Ceschia et al, 2002;Knott, 2004;Charru et al, 2010;Šimpraga et al, 2011;Michelot et al, 2012) have used it to assess intra-annual growth of European beech. Fluctuations of stem diameter are result of contraction and expansion caused by irreversible increment of xylem, changes in tissue water storage, wood thermal properties and internal tensions of conducting elements (Daudet et al, 2005).…”