The adjustment of growth, sapwood area, heartwood area, and sapwood saturated permeability of balsam fir after different intensities of pruning

Abstract

Balsam fir trees established from advanced regeneration following a clear-cut in 1970 were pruned in June 1985 to live crown ratios of 0.6, 0.4, and 0.2 compared with control trees, which had live crown ratios of 0.8. After two growing seasons, we investigated the homeostatic adjustment of these trees to the loss of their foliage. The height growth, basal area growth, sapwood cross-sectional area, heartwood area, and sapwood saturated permeability of the trees that were pruned to a 0.6 live crown ratio were not significantly different from those of the controls. On the other hand, height growth increment following pruning was reduced 16.7 cm (23%) and 19.5 cm (27%) for the trees pruned to 0.4 and 0.2 live crown ratios, respectively. Furthermore, basal area growth following pruning was reduced 3.2 cm2 (30%) and 6.5 cm2 (61%), respectively. While trees in both the 0.4 and 0.2 live crown ratio pruning treatments did adjust their breast height sapwood area in response to the removal of foliage, the nature of this adjustment differed between the two treatments. For the trees with the 0.4 live crown ratio, sapwood area was reduced because of a reduction in basal area growth but the area of heartwood remained unchanged. For the trees with the 0.2 live crown ratio, the changes in sapwood area were due both to a reduction in basal area growth and an expansion of the heartwood. The saturated permeability of sapwood was not significantly affected by pruning. The adaptive implications of balsam fir's response to the loss of foliage are discussed in terms of the optimizing the allocation of a limited amount of available carbon.

Stand growth scenarios for Tectona grandis plantations in Costa Rica

“…Ericsson (1966) reported lower heartwood content in thinned stands (33%) than in unthinned stands (40%) in a survey study on Pinus sylvestris stands. Margolis et al (1988) reported an increased heartwood area in heavily pruned Abies balsamea trees. In a study on the effects of pruning regimes in 25-year-old Pinus sylvestris by Långström and Hellqvist (1991), pruning reduced growth and increased heartwood area.…”

Effect of pruning on tree growth, yield, and wood properties of Tectona grandis plantations in Costa Rica

“…For species other than teak, Margolis et al (1988) consider that the unstained center of the stem, which can be interpreted as heartwood, may be temporarily immobilized sapwood rather than true heartwood; this explains the difficulty to establish the boundary between heartwood and sapwood, and could be used eventually as an indicator of stress. These authors report an increment in heartwood area in heavily pruned Abies balsamea (L.) Mill.…”

Variation of conducting area in stems of European larch (Larix deciduas) growing in fresh mixed coniferous forest and fresh mixed forest sites

“…The area of sapwood ring is frequently calculated by researchers as a value used to describe conducting area and relate it to biometric traits of tree crowns (Ganskopp, Miller 1986;Dean et al 1988;Margolis et al 1988;Mörling, Valinger 1999;McDowell et al 2002;Medhurst, Beadle 2002;Sellin, Kupper 2003;Stancioiu, O'Hara 2005;Longuetaud et al 2006). However, the areas of late wood ring contained within sapwood, neither participating nor involved in water conduction to a limited extent, result in a situation when the sapwood area reduced by the area of late wood, i.e.…”