Crown architecture of grafted Stone pine (Pinus pinea L.): shoot growth and bud differentiation

Abstract

The singular umbrella-like crown shape of Stone pine can be interpreted as a consequence of primary shoot-growth patterns and posterior axis differentiation due to differential secondary growth and down-bending of branches. This paper centres on the first aspect, analysing the growth, branching and flowering behaviour of about 5,000 individual shoots on 27 grafted Stone pines. The data measurement on standing trees allowed to study correlations of topologic and geometric variables in the shoot and their ancestors. The only significant correlations were found with parameters of the mother shoot formed the previous year and with the number of cones born 3 years before by the respective ancestor. The fitted relationships between geometric and topologic shoot and branch variables are the first step of a structural model construction that can be completed with functional components like a radiation and a carbon allocation submodel, stressing the importance of the heavy Stone pine cones as carbon sinks, with a total annual allocation similar to stem wood. In conclusion, the Stone pine crown shape emerges as consequence of the lack of initial vigour differentiation between stem and main-branch apical meristems that favour the generalized sylleptic reiteration in the open-grown trees.

Biomass allometry and carbon factors for a Mediterranean pine (Pinus pinea L.) in Portugal

“…The higher BEF aboveground found is in consistence with the species structure and geometry -lack of apical dominance with a polyarchic ramification resulting in a crown shape wider than deeper (Mutke et al, 2005c) and with a proportionally heavier crown compared with the rest of the aboveground woody tissues. Biomass allocation pattern for P. pinea changes significantly with stand density (Fig.…”

“…However at these stages, the absence (or reduced) competition for light, and probably the efficient access to water, allow codominant branches to stiffen due to secondary growth and to be maintained in the canopy surface in the best light conditions, suffering less down-bending. These heavier and stronger branches are the ones able to sustain more and heavier cones (Mutke et al, 2005c). This explains why higher cone productions can only be achieved in open stands (usually with less than 100 trees ha -1 ).…”

Enhanced tools for predicting annual stone pine (Pinus pinea L.) cone production at tree and forest scale in Inner Spain

“…This effect has been interpreted as reduction in the number of female flowers induced by the high physiological cost during the ripening of heavy crops (Mutke et al, 2005b). This inhibitory effect of depletion has been largely described in other species (e.g.…”

Selection of Mediterranean stone pine clones for cone production

“…Más allá de los requerimientos básicos de cualquier cultivo leñoso -producción de plantones de primera calidad, preparación del terreno, control de la vegetación competidora y de plagas del árbol y del producto-, las cuestiones pendientes van desde una caracterización de las clases de territorio aptas para las plantaciones injertadas de carácter comercial, la definición del espaciamiento correcto para evitar efectos de sombreo que desencadenen el desarrollo de ramas dominadas sin floración femenina (Mutke et al, 2005c), la aplicación de podas de aclareo para equilibrar el interior de la copa y evitar precisamente estas ramas de sombra, hasta la necesidad de ensayar fertilizaciones para garantizar el estado nutricional ópti-mo del arbolado, influyendo todas ellas muy posiblemente en la moderación del carácter vecero (Baldini, 1986). A escala experimental cabe plantearse incluso el riego, aunque como remarcan Castaño et al (2004) su aplicación encarecería en demasía una explotación que en tierras de regadío difícilmente podrá competir con otros cultivos o con usos de suelo más rentables.…”