Allocation of above-ground growth in Pinus sylvestris – impacts of tree size and competition

Abstract

Vanninen, P. 2004. Allocation of above-ground growth inPinus sylvestris -impacts of tree size and competition. Silva Fennica 38(2): 155-166.The effect of tree age, size and competition on above ground growth allocation was studied with 69 Pinus sylvestris trees. Competition was described by tree-level indicators (needle density, crown ratio and height-diameter ratio). The stem, branch and needle growth were determined by stem and branch radial increments and tree level biomass analysis. Combined growth of compartments was strongly correlated with needle mass. Furthermore, tree age, size and competition indicators affected the allocation of growth among the compartments. The allocation of growth to stem and needle increased with tree age and size while the allocation of growth to branch decreased. The increasing crown ratio increased allocation of growth to branches. The combined growth of the components and separate growth of needles, branches and stem were related to needle mass. However, competition and tree size were significant additional explanatory variables when the stem, branch and needle growth were estimated according to needle mass. The growth efficiency increased with relative tree height and decreased with increasing needle density. Allocation of Above-ground Growth in Pinus sylvestris -Impacts of Tree Size and Competition

Response of biomass allocation patterns to thinning in Pinus halepensis differs under dry and semiarid Mediterranean climates

“…Regarding allocation patterns, the concepts and mechanisms involved in the ecophysiological processes underlying allocation to different biomass components are not well understood and are not, therefore, included in practical growth forest models (Landsberg and Sands 2011). Changes in the allocation of biomass components have been previously related to factors such as tree age, size and the competitive status, supported by the pipe model theory and functional carbon balance (Vanninen 2004). Following functional carbon balance (Brouwer 1983), we expected root partitions to increase under limited nutrient or water availability, i.e.…”

“…By considering that allocation patterns differ within tree species (Vanninen 2004), we hypothesised that inherited adaptive traits to fire regimes in P. halepensis, such as precocious and copious cone production, could also shape biomass allocation patterns, particularly at younger stages, and that these patterns could be modulated by climate and competition.…”

Genetic variation in the diameter–height relationship in Scots pine (Pinus sylvestris)

“…Furthermore, allocation of biomass to stem growth is likely to occur when greater intertree competition is present, and suppressed trees then become more slender (Sumida et al 1997;Vanninen 2004), although it has been suggested that the lack of independence between neighbouring units can cause biased treatment effects in forest genetic experiments (Magnussen 1993). To control for microsite heterogeneity and intertree competition, spatial indices were used as covariates in the models in an iterative nearestneighbour analysis (NNA).…”

“…The inverse of the d-h relationship is often used and is referred to as ''stem slenderness'' or ''slenderness coefficient'' (the ratio of total height to diameter at 1.3 m). Both the d-h relationship and the corresponding inverse expression of stem form (stem slenderness) are well-studied tree characteristics in the area of stem biomass allocation (e.g., Ilomäki et al 2003;Vanninen 2004) and in forest-tree growth modeling (e.g., Sharma and Zhang 2004). Waghorn et al (2007) revealed that stem slenderness was a substantially more important indicator of wood stiffness than diameter.…”

Optimizing stand structure for trade‐offs between overstory timber production and understory plant diversity: A case‐study of a larch plantation in northwest China

“…An increase in tree density reduces the single tree volume, especially in higher density ranges, due to stronger competition of light, water, and nutrition (Bauhus et al, ); furthermore, it increases the total timber volume per unit area (Litton, Ryan, & Knight, ) with a varying rate due to the interaction of increasing tree numbers and decreasing tree size (Miller & Bender, ; Vanninen, ). Such a tree density effect has been well modeled by a power function, as shown by Smith et al ().…”