Sources of within- and between-stand variability in specific leaf area of three ecologically distinct conifer species

Abstract

of within-and between-stand variability in specific leaf area of three ecologically distinct conifer species. Annals of Forest Science, Springer Verlag/EDP Sciences, 2008, 65 (1), pp.1-10. <hal-00884146>Ann. For. Sci. 65 (2008) Laws.) were used to estimate variability of SLA within a canopy and its relationship to tree-and stand-level covariates, and to predict SLA at various locations in tree crowns. Also, in the case of hybrid spruce, variation in SLA due to different relative horizontal lengths from the bole was examined. In all species, SLA systematically increased from tree tip to crown base and decreased with foliage age class. Cardinal direction did not have a highly significant influence in either Douglas-fir or hybrid spruce, but SLA did significantly decrease from branch tip to bole in hybrid spruce. Tree-and stand-level (e.g. density, site index) factors had relatively little influence on SLA, but stand age did have a significant positive influence. For ponderosa pine, a significant relationship between canopy mean current-year SLA and carbon isotope discrimination was also found, suggesting the importance of water stress in this species. An equation was fitted to estimate SLA at various points in the canopy for each species and foliage age class using absolute height in the canopy, relative vertical height in the tree, and stand age. Les relations entre SLA et des covariables à l'échelle de l'arbre ou du peuplement ont été précisées, un modèle prédictif de SLA à différents niveaux dans les couronnes a été construit. Dans le cas de l'épicéa, l'impact de la distance de branche entre l'aiguille et le tronc a également été testé. Dans toutes les espèces, SLA augmentait systématiquement du sommet des arbres à la base de la couronne, et diminuait avec la classe d'âge des aiguilles. La direction cardinale n'avait guère d'influence sur SLA ni dans le cas du Douglas ni dans celui de l'épicéa ; mais SLA diminuait systématiquement depuis l'extrémité des branches vers le tronc. Les facteurs arbre et peuplement (comme la densité, l'indice de productivité de la station) n'avaient que peu d'impact sur SLA alors que l'âge du peuplement avait un effet significatif et positif. Pour le pin ponderosa, une relation significative a été détectée entre la valeur moyenne de SLA des aiguilles de l'année et la discrimination isotopique du carbone, ce qui suggère l'impact des contraintes hydriques pour cette espèce. Un modèle de prédiction de SLA à différentes positions dans la canopée a été ajusté sur les données de chaque espèce et classe d'âge, en se basant sur la hauteur dans la canopée, la hauteur relative dans l'arbre et l'âge du peuplement.surface spécifique foliaire / masse surfacique des aiguilles / sapin de Douglas / épicéa hybride / pin ponderosa / modèles mixtes

Needle-Age Related Variability in Nitrogen, Mobile Carbohydrates, and δ13C within Pinus koraiensis Tree Crowns

“…Leaf N concentration was found to be strongly positively correlated with leaf photosynthetic capacity both in tropical and temperate forest trees [58], [64], [68], [69]. Schoettle [45] found that current-year needles had higher N concentration and higher photosynthetic capacity than 1-yr-old needles in adult Pinus aristata trees.…”

Structural controls on photosynthetic capacity through juvenile‐to‐adult transition and needle ageing in Mediterranean pines

“…Needle age also influences foliage structural traits and nutrient content (Mediavilla et al, 2014;Niinemets, 2002;Niinemets, García-Plazaola, & Tosens, 2012;Teskey, Grier, & Hinckley, 1984;Weiskittel, Temesgen, Wilson, & Maguire, 2008), but the effects of these modifications on age-dependent changes in needle photosynthetic potentials are still not fully resolved. Thus, in mature trees we studied variation in foliage photosynthetic potentials in non-senescent adult current-year, 1-year-old and 2-year-old needles.…”

Within-stand and seasonal variations of specific leaf area in a clonal Eucalyptus plantation in the Republic of Congo

“…Plant water status during leaf development, and/or the amount of photosynthetically active radiation (PAR) absorbed by the leaf during its formation have been identified as important factors influencing the SLA of adult leaves (Le Roux et al, 1999;Niinemets, 2007). Specific leaf area is generally known to decrease from the bottom of the canopy to its top (Le Roux et al, 1999;Marshall and Monserud, 2003;Sellin and Kupper, 2006;Weiskittel et al, 2008;Davi et al, 2008;Cavaleri Forest Ecology and Management 259 (2010) [1796][1797][1798][1799][1800][1801][1802][1803][1804][1805][1806][1807] et al, submitted for publication), or from the interior of individual tree crowns to their periphery (Han et al, 2003;Sellin and Kupper, 2006;Weiskittel et al, 2008), and these variations are considered either as an adaptation to a varying light environment within the canopy (e.g., Niinemets, 1997;Kenzo et al, 2006;White and Scott, 2006), allowing optimization of carbon gains (e.g., Rambal et al, 1996;Meir et al, 2002), or as a result of increased leaf water stress (decreased leaf water potential) with height or branch length, due to gravity or path length resistance (Koch et al, 2004;Woodruff et al, 2004;Ryan et al, 2006;He et al, 2008;Du et al, 2008). Height-related variation in SLA is commonly described by exponential functions relating SLA or LMA to the cumulative leaf area index (from the top of the canopy to its bottom), similar to the functions used to model light attenuation inside forest canopies (Rambal et al, 1996;Davi et al, 2008), or by exponential functions relating SLA ...…”