Bark

About: Bark is a research topic. Over the lifetime, 12004 publications have been published within this topic receiving 147931 citations.

Fire‐induced tree mortality in a neotropical forest: the roles of bark traits, tree size, wood density and fire behavior

Abstract: Large-scale wildfires are expected to accelerate forest dieback in Amazonia, but the fire vulnerability of tree species remains uncertain, in part due to the lack of studies relating fire-induced mortality to both fire behavior and plant traits. To address this gap, we established two sets of experiments in southern Amazonia. First, we tested which bark traits best predict heat transfer rates (R) through bark during experimental bole heating. Second, using data from a large-scale fire experiment, we tested the effects of tree wood density (WD), size, and estimated R (inverse of cam- bium insulation) on tree mortality after one to five fires. In the first experiment, bark thickness explained 82% of the variance in R, while the presence of water in the bark reduced the difference in temperature between the heat source and the vascular cambium, perhaps because of high latent heat of vaporization. This novel finding provides an important insight for improving mechanistic models of fire-induced cambium damage from tropical to temperate regions. In the second experiment, tree mortality increased with increasing fire intensity (i.e. as indicated by bark char height on tree boles), which was higher along the forest edge, during the 2007 drought, and when the fire return inter- val was 3 years instead of one. Contrary to other tropical studies, the relationship between mortality and fire intensity was strongest in the year following the fires, but continued for 3 years afterwards. Tree mortality was low ( � 20%) for thick-barked individuals ( � 18 mm) subjected to medium-intensity fires, and significantly decreased as a function of increasing tree diameter, height and wood density. Hence, fire-induced tree mortality was influenced not only by cambium insulation but also by other traits that reduce the indirect effects of fire. These results can be used to improve assessments of fire vulnerability of tropical forests.

Specific gravity and other properties of wood and bark for 156 tree species found in North America

Abstract: This paper reports information for the estimation of biomass for 156 tree species found in North America for use in national forest inventory applications. We present specific gravities based on average green volume as well as 12 percent moisture content volume for calculation of oven-dry biomass. Additional information is included on bark thickness, bark voids, and bark percentages by species and green and dry weight of wood and bark.Note: Values in Table 5 were corrected on Feb. 10, 2010. See page 35 of this publication.

Bark thickness and fire regime

Abstract: Summary 1. Bark is a vital and very visible part of woody plants, yet only recently has bark characteristics started to be considered as key traits structuring communities and biomes. Bark thickness is very variable among woody plants, and I hypothesize that fire is a key factor selecting for a thick bark, and thus, at the global scale, a significant proportion of the variability in bark thickness is explained by the variability in fire regimes. Previous research has focused on the importance of bark thickness mainly in surface-fire regimes; here I generalize this idea and present a conceptual framework to explain how the different drivers that affect fire intensity have shaped bark thickness, in conjunction with other plant traits. 2. I first review methods used to study bark thickness and then provide examples of bark thickness patterns from a wide range of ecosystems subject to different fire regimes (understorey fires, grass-fuelled surface fires, grass-fuelled crown fires and infrequent fires). 3. There are some fire regimes that select for thick barks, while some only in the base of the trunk (e.g. understorey fires), others select for a thick bark on the whole plant (e.g. grassfuelled crown fires). There are also fire regimes in which allocating resources to a thick bark is not adaptive (e.g. woody-fulled crown fires). 4. Fire regime can explain a large proportion of the variability of bark thickness at the global scale, and thus, this trait varies across ecosystems in a predictable manner; however, the current paucity of data limits a fully accurate analysis.