Sapwood Thickness Research Articles

Sapwood area~DBH allometries for 14 common tree species in a successional tropical forest in Thailand

AbstractSapwood area is an important parameter for estimating canopy transpiration in the forest water cycle. However, sapwood area highly varies across species and forest ecosystems and is difficult to measure directly. Therefore, species- and site-specific allometric equations are needed to estimate the sapwood area of all trees in a forest. Here, we conducted a comprehensive campaign to measure sapwood thickness and to estimate the sapwood area of 14 common tree species in a successional forest in Thailand. These data represent the first comprehensive measurements of sapwood area in south-east Asian successional forests growing under diverse environmental conditions in terms of soil moisture and canopy density. The results show that a power function can significantly explain the relationship between sapwood area and stem size, represented by diameter at breast height (DBH), in all species in both primary and secondary forests. Interestingly, a single equation could describe the sapwood area~DBH relationship in all species and forest stages, except for Dipterocarpus gracilis, an emergent, dominant species in the primary forest. The latter showed slower growth in sapwood area once the trees reached a DBH of ~30 cm. Overall, our results can benefit future studies that estimate canopy transpiration of tropical forests with similar conditions as in our study sites.

Development of heartwood, sapwood, bark, pith and specific gravity of teak (Tectona grandis) in fast-growing plantations in Costa Rica

To elucidate the development of heartwood, bark, sapwood, pith and specific gravity of wood in fast-growing teak (Tectona grandis) plantations in Costa Rica, we sampled three trees in each of 55 plantations and modelled each variable with age, site and different tree heights. Age and stand density of plantations were significant correlated with stem diameter at breast height and total height of the tree. Formation of heartwood was initiated at the age of 4-year-old and increased in direct proportion with age. The age of plantation had a significant relationship with stem diameter at breast height, heartwood percentage, sapwood thickness, sapwood percentage, percentage of bark, pith diameter and percentage, and specify gravity. The model for these tree parameters was model with these parameters as dependent variable and in relation to age as independent variable.

Top-down seasonal streamflow model with spatiotemporal forest sapwood area

Forest growth dynamics affect streamflow with changes in actual evapotranspiration (AET) during forest regeneration. Using a “top-down” model approach, we present a seasonal forest hydrology model that estimates streamflow in forested catchments containing sparse soil and climate data. Across a 1423 km2 remote study area, a rainfall interpolation procedure using available rainfall data and information on terrain was integrated into a new seasonal streamflow model, called ABCF, which uses catchment sapwood area (SA) as the emergent property that equilibrates with potential evapotranspiration (PET), and a soil storage threshold that reduces AET below PET when soil water is limiting. We produce seasonal estimates of streamflow with Nash Sutcliffe efficiencies of 0.85, 0.87, and 0.91 for three major catchments within the study area. A fundamental feature of the “top-down” model approach is the use of LiDAR data and forest inventory data to model forest structural properties that relate strongly with SA. Building on our previous work with this modelling framework, our representation of eco-hydrological properties of the forest has been refined with a more accurate procedure for estimating stand mean sapwood thickness, and hence SA, and a remotely sensed tree stocking density (N) of old-growth forests to correct the temporal evolution of N as a means to improve SA estimates. Regional consistency of model parameters shows that the “top-down” modelling framework may be used to estimate streamflow in ungauged catchments using a forest growth model. The seasonal model generalised for both water-limited and water-unlimited forest conditions has significant potential for application in water supply planning and drought security.

Heartwood formation and prediction of heartwood parameters in Tectona grandis L.f. trees growing in forest plantations in Costa Rica

La présente étude vise à établir les variations du duramen (pourcentage, diamètre, rayon, volume) rapportées à la hauteur des arbres et à l’épaisseur de l’aubier, ainsi que l’âge de début de formation du duramen et sa hauteur maximale pour les arbres de l’essence Tectona grandis. Les résultats de l’échantillonnage de seize plantations réparties dans différentes zones du Costa Rica, âgées de 2 à 22 ans, montrent que l’aubier est plus épais entre 2 et 10 ans d’âge qu’entre 10 et 22 ans. La formation du duramen commence à la base des arbres âgés de 2 à 3 ans, mais il n’apparaît à hauteur de poitrine qu’à partir de 3 à 4 ans. Le duramen disparaît à une hauteur allant de 0 à 90 % de la hauteur totale selon l’âge de l’arbre. Enfin, des modèles statistiques prédictifs ont été développés pour l’épaisseur de l’aubier et pour le rayon, la hauteur maximale et le pourcentage du duramen, en se basant sur le modèle Y = K0 + K1*(épaisseur de l’aubier) + K2*(hauteur relative de l’échantillonnage) + K3*(diamètre à hauteur de poitrine) + K4*(âge de l’arbre). Ces modèles indiquent des coefficients de détermination de 70 %, 90 %, 95 %, 73 % et 31 %, respectivement.

Predicting long‐term streamflow variability in moist eucalypt forests using forest growth models and a sapwood area index

AbstractA major challenge in surface hydrology involves predicting streamflow in ungauged catchments with heterogeneous vegetation and spatiotemporally varying evapotranspiration (ET) rates. We present a top‐down approach for quantifying the influence of broad‐scale changes in forest structure on ET and hence streamflow. Across three catchments between 18 and 100 km2 in size and with regenerating Eucalyptus regnans and E. delegatensis forest, we demonstrate how variation in ET can be mapped in space and over time using LiDAR data and commonly available forest inventory data. The model scales plot‐level sapwood area (SA) to the catchment‐level using basal area (BA) and tree stocking density (N) estimates in forest growth models. The SA estimates over a 69 year regeneration period are used in a relationship between SA and vegetation induced streamflow loss (L) to predict annual streamflow (Q) with annual rainfall (P) estimates. Without calibrating P, BA, N, SA, and L to Q data, we predict annual Q with R2 between 0.68 and 0.75 and Nash Sutcliffe efficiency (NSE) between 0.44 and 0.48. To remove bias, the model was extended to allow for runoff carry‐over into the following year as well as minor correction to rainfall bias, which produced R2 values between 0.72 and 0.79, and NSE between 0.70 and 0.79. The model under‐predicts streamflow during drought periods as it lacks representation of ecohydrological processes that reduce L with either reduced growth rates or rainfall interception during drought. Refining the relationship between sapwood thickness and forest inventory variables is likely to further improve results.

Use of a forest sapwood area index to explain long‐term variability in mean annual evapotranspiration and streamflow in moist eucalypt forests

AbstractMean sapwood thickness, measured in fifteen 73 year old Eucalyptus regnans and E. delegatensis stands, correlated strongly with forest overstorey stocking density (R2 0.72). This curvilinear relationship was used with routine forest stocking density and basal area measurements to estimate sapwood area of the forest overstorey at various times in 15 research catchments in undisturbed and disturbed forests located in the Great Dividing Range, Victoria, Australia. Up to 45 years of annual precipitation and streamflow data available from the 15 catchments were used to examine relationships between mean annual loss (evapotranspiration estimated as mean annual precipitation minus mean annual streamflow), and sapwood area. Catchment mean sapwood area correlated strongly (R2 0.88) with catchment mean annual loss. Variation in sapwood area accounted for 68% more variation in mean annual streamflow than precipitation alone (R2 0.90 compared with R2 0.22). Changes in sapwood area accounted for 96% of the changes in mean annual loss observed after forest thinning or clear‐cutting and regeneration. We conclude that forest inventory data can be used reliably to predict spatial and temporal variation in catchment annual losses and streamflow in response to natural and imposed disturbances in even‐aged forests. Consequently, recent advances in mapping of sapwood area using airborne light detection and ranging will enable high resolution spatial and temporal mapping of mean annual loss and mean annual streamflow over large areas of forested catchment. This will be particularly beneficial in management of water resources from forested catchments subject to disturbance but lacking reliable long‐term (years to decades) streamflow records.

General, physical and mechanical properties, termites resistance and drying defects of lumber of Tectona grandis from plantations of different climatic and sites fertility condition

The influence of climatic and site fertility conditions affect wood quality from fast growing trees. The change in tree diameter, thickness of sapwood, heartwood percentage and bark and pith tissue, physical and mechanical properties, resistance to termite attack and the presence of drying defects on lumber boards were evaluated. Four teak trees (Tectona grandis L.f.) from fast growing plantations in Costa Rica were selected for the study. Teak trees of 11 years old growing in two climatic conditions and two fertility types (high and low fertility) in Costa Rica were studied. The results showed that tree diameter, sapwood thickness, pith diameter and its percentage were higher in the climate with more rainfall and greater fertility. However, the percentage of heartwood and bark were higher at low fertility sites with less rainfall. It was also observed that only sites with low fertility produce modifications in specify gravity, fiber saturation point, initial moisture content, MOR in flexion in green and dry condition, MOE in bending and resistance to termite attack. Incidence and magnitude of defects increased with drying, and were mainly affected when wood comes from younger trees from high fertility sites and growing in tropical moist forest climate.

Radial and Axial Variation of Heartwood Properties and Extractives in Mature Trees of Eucalyptus globulus

Mature 40-year-old trees of Eucalyptus globulus harvested in Portugal were studied to determine the heartwood development and variation of basic density and extractives content at different stem height levels. The heartwood radius decreased regularly from bottom to top in all the trees: for instance 22.2 cm, 13.0 cm, and 10.4 cm, respectively, at the 0%, 35%, and 60% height levels of tree 1. The average sapwood thickness was 2.8 cm at the stem base. The mean basic density fell in a range between 0.607 g cm-3 and 0.782 g cm-3 and was highest in the outer heartwood at all height levels. The total content of extractives varied axially and radially along the stem. It decreased until the 35% height level, and then it remained approximately constant upwards. The extractives content increased radially from the sapwood to the inner heartwood (6.2% to 12.5% at the base). Ethanol-soluble compounds were the major fraction at the base: 4.9%, 8.4%, and 10.9% of dry mass, respectively, for sapwood, outer heartwood, and inner heartwood. The non-polar extractives were obtained by dichloromethane extraction in very low amounts.

A new method for measuring stand sapwood area in forests

AbstractWe introduce a novel methodology for measuring stand sapwood area (SA), which provides a useful indicator of evapotranspiration from forest stands. The method is demonstrated in a 73‐year‐oldEucalyptus regnansforest comprising 784 stems over a 5 ha area. We used photos of stump cross‐sections to differentiate sapwood from heartwood and found 90% of stump segments to have a visible transition boundary. The digital images were corrected for lens distortion and scaled to an actual cross‐sectional area, with resulting stump perimeters corresponding well with field‐measured perimeters traced using string (root‐mean‐square error = 4 cm,R2 = 0.99). Calculated SA and basal area (BA) at stump height were coupled with tree and sapwood taper data to predict the SA:BA ratio at 1.3 m height (). Tree taper data were coupled with stump dimensions data in a mixed‐effects model to predict each stump's BA at 1.3 m, and sapwood taper data from buttress logs were used to improve each stems. Using this procedure, we found our study site to have anof 0.21 and total stand SA at 1.3 m height of 9.3 m2 ha−1.We quantified the bias in traditionalestimates that use cores to measure sapwood thickness and diameter tape to calculate SA. We show traditional methods underestimatethat increases with tree diameter and decreases with stem circularity, whereas our methodology gave more accurate measures of SA in large buttressing trees. Our methodology also provides a more efficient way of generating maps of SA variation across large forested catchments. Copyright © 2014 John Wiley & Sons, Ltd.

Sapwood and Heartwood Contents on the Logs and Sawn Boards of Manglid (Manglieta glauca Bl.)

The aim of this research is to identify the characteristics of sapwood and heartwood of manglid wood both in the logs and sawn boards; and to evaluate the differences of sapwood and heartwood content of sawn board from two sawing patterns: live sawing pattern and semi quarter sawing pattern. Totally 30 manglid logs coming from private forest in Sodonghilir sub-District, Tasikmalaya Regency were used as samples. About 35 sawn boards from each of sawing pattern were randomly chosen as specimens for sawn board observation. Result shows that manglid wood has thicker heartwood content than the sapwood on the log cross section, with the average of the heartwood and sapwood thickness is 17.04 and 6.57 cm, respectively. The thickness of heartwood part is positively correlated with the log diameter. Meanwhile, the percentage of the heartwood volume increases but the percentage of the sapwood decreases by the increasing of the log diameter. The higher thickness of the heartwood part compared to the sapwood part is consistent in the case of sawn board both from live sawing pattern and semi quarter pattern. Sawn board from the live sawing pattern has a lower sapwood percentage than the heartwood percentage on the width section. Key words: heartwood, live sawing, log, sapwood, semi quarter sawing

Climate‐related trends in sapwood biophysical properties in two conifers: avoidance of hydraulic dysfunction through coordinated adjustments in xylem efficiency, safety and capacitance

In the Pacific north-west, the Cascade Mountain Range blocks much of the precipitation and maritime influence of the Pacific Ocean, resulting in distinct climates east and west of the mountains. The current study aimed to investigate relationships between water storage and transport properties in populations of Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) adapted to both climates. Sapwood thickness, capacitance, vulnerability to embolism, and axial and radial conductivity were measured on samples collected from trunks of mature trees. The sapwood of ponderosa pine was three to four times thicker than Douglas-fir. Radial conductivity was higher in west-side populations of both species, but axial conductivity was higher in the east-side populations and in Douglas-fir. Eastern populations of both species had sapwood that was more vulnerable to embolism than west-side populations. Sapwood capacitance was similar between species, but was about twice as great in east-side populations (580 kg m⁻³ MPa⁻¹) as in west-side populations (274 kg m⁻³ MPa⁻¹). Capacitance was positively correlated with both mean embolism pressure and axial conductivity across species and populations, suggesting that coordinated adjustments in xylem efficiency, safety and water storage capacity may serve to avoid embolism along a gradient of increasing aridity.

Parâmetros dendrométricos e correlações com propriedades tecnológicas em um híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis

A qualidade da madeira aparentemente está associada às características dendrométricas, que por sua vez são influenciadas pelas condições de crescimento. Os objetivos deste estudo foram a caracterização dendrométrica e a realização de correlações de Pearson entre alguns parâmetros tecnológicos da madeira do híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis sob três estratos silviculturais. Os dados dendrométricos foram analisados mediante a análise de regressão. Os resultados mostraram que o híbrido apresenta comportamento similar ao das demais madeiras da mesma espécie que cresceram em outras regiões, destacando-se a espessura do alburno no E1 (talhadia simples, 70 meses e com um desbaste), com pouca variação ao longo do fuste. Todas as árvores apresentaram, em geral, baixa conicidade ao longo do fuste e baixo volume de casca entre os estratos. Na correlação de Pearson foram avaliados entre si nove parâmetros dendrométricos, sete físicos e três mecânicos, longitudinalmente em seções de 3 m e na posição medula-casca nas duas primeiras toras. Os coeficientes encontrados demonstram haver fortes correlações entre as propriedades, destacando-se a densidade básica em relação às demais características e o coeficiente de anisotropia, ambas importantes no processo de desdobro e secagem da madeira. Não houve correlações significativas nas contrações lineares e volumétricas ao longo do comprimento do fuste. A variação radial mostrou boas correlações entre todas as propriedades mecânicas avaliadas nas duas primeiras toras. Em contrapartida, as propriedades físicas avaliadas na posição radial não apresentaram correlações significativas.

Improving models of forest nutrient export with equations that predict the nutrient concentration of tree compartments

• The objective of this study was to explore the distribution of major nutrients (N, P, K, Ca and Mg) in the aboveground compartments of an intensively managed tree species (Pinus pinaster Ait.). A total of 53 trees were cut down in even-aged stands respectively 8, 16, 26, 32 and 40 years old. The nutrient concentrations of the aboveground compartments were analysed. • Nutrient concentrations of foliage did not vary with any of the variables used, except needle age. Nutrient concentrations of living branches, stem bark, stem sapwood, stem heartwood, stemwood and stem decreased with increasing branch diameter, bark thickness, sapwood thickness and heartwood thickness, respectively. Beyond a certain value of the predictive variable (stem diameter ≈ 15 cm; branch diameter ≈ 2.5 cm), the concentration of all the nutrients stabilised. • A 50 year-old pine stand was used to obtain a validation dataset for nitrogen concentration. For this nutrient, the regression relationships gave satisfactory estimates for most compartments (mean error = 12–25%) and particularly for the stem. • A procedure is proposed to estimate the nutrient exports associated with harvests of Pinus pinaster biomass.

Stem respiratory potential in six softwood and four hardwood tree species in the central cascades of Oregon.

Mature and old growth trees of varying sapwood thickness were compared with regard to stem respiration. An increment core-based, laboratory method under controlled temperature was used to measure tissue-level respiration (termed respiratory potential) of ten different tree species. Bark (dead outer and live inner combined), sapwood, and heartwood thickness measurements were used to predict sapwood volume from stem diameter (including bark) for four of the ten species. These predictions of sapwood volume were used to scale respiratory potential to the main-bole level (excluding all branches). On the core level, species that maintained narrow sapwood (8-16% of bole radius) such as Pseudotusga menziesii, Taxus brevifolia, and Thuja plicata, had sapwood respiratory potentials in the lower bole that were 50% higher (P<0.05) than species with wide sapwood (>16% of bole radius), such as Abies amabilis, Pinus monticola, and Tsuga heterophylla. This pattern was not observed for inner bark respiratory potential, or for sapwood respiratory potential within the crown. On the main-bole level, respiratory potential per unit volume was inversely correlated to the live bole volumetric fraction (inner bark plus sapwood divided by whole bole volume) (Adj. R(2)=0.6). Specifically, tree species with 18-20% of the main bole alive potentially respired 1.3-3 times more per unit live bole volume than species with over 40%, suggesting that the live bole was less metabolically active in tree species that maintained large volumes of sapwood.

Vertical heartwood variation patterns and prediction of heartwood volume in Pinus canariensis Sm.

Heartwood and sapwood distribution along the stem were assayed in 26 Canary Island pines growing along the natural range of the species at the Canary Archipelago. Trees were sampled at breast height and approximately every 2 m up to the lowest section without heartwood. Heartwood and sapwood thickness, together with age and radial growth traits were measured in each section. Heartwood tapered towards the top of the tree and disappeared at a certain height. Sapwood distribution was more variable among individuals; sapwood width was almost constant in some individuals but tapered slightly or with a curvilinear variation in others. Two general patterns of heartwood and sapwood variation were defined, one characterised by a constant decrease in heartwood percentage and subsequently a slight sapwood variation along the stem (uniform pattern) and another one with a peak in heartwood percentage at a height between 4 and 8 m (irregular pattern). The relative crown height to total tree height was significantly higher in the second group, averaging 49% versus 32% in the uniform group. A mechanical–physiological hypothesis is given to explain this result in the light of similar results in other species. A model including heartwood radius at breast and tree height as predicting variables was able to explain 90% of heartwood radius at a given height in the stem. A similar model with sapwood width at breast height explained 80% of sapwood width variation along the stem. Heartwood volume was predicted by means of log–linear regression models including heartwood diameter at breast height and tree height ( r 2=97.5%). Sapwood volume was better predicted through stem diameter at breast height and tree height ( r 2=92.7%).

Radial variation in sap velocity as a function of stem diameter and sapwood thickness in yellow-poplar trees.

Canopy transpiration and forest water use are frequently estimated as the product of sap velocity and cross-sectional sapwood area. Few studies, however, have considered whether radial variation in sap velocity and the proportion of sapwood active in water transport are significant sources of uncertainty in the extrapolation process. Therefore, radial profiles of sap velocity were examined as a function of stem diameter and sapwood thickness for yellow-poplar (Liriodendron tulipifera L.) trees growing on two adjacent watersheds in eastern Tennessee. The compensation heat pulse velocity technique was used to quantify sap velocity at four equal-area depths in 20 trees that ranged in stem diameter from 15 to 69 cm, and in sapwood thickness from 2.1 to 14.8 cm. Sap velocity was highly dependent on the depth of probe insertion into the sapwood. Rates of sap velocity were greatest for probes located in the two outer sapwood annuli (P1 and P2) and lowest for probes in closest proximity to the heartwood (P3 and P4). Relative sap velocities averaged 0.98 at P1, 0.66 at P2, 0.41 at P3 and 0.35 at P4. Tree-specific sap velocities measured at each of the four probe positions, divided by the maximum sap velocity measured (usually at P1 or P2), indicated that the fraction of sapwood functional in water transport (f(S)) varied between 0.49 and 0.96. There was no relationship between f(S) and sapwood thickness, or between f(S) and stem diameter. The fraction of functional sapwood averaged 0.66 +/- 0.13 for trees on which radial profiles were determined. No significant depth-related differences were observed for sapwood density, which averaged 469 kg m(-3) across all four probe positions. There was, however, a significant decline in sapwood water content between the two outer probe positions (1.04 versus 0.89 kg kg(-1)). This difference was not sufficient to account for the observed radial variation in sap velocity. A Monte-Carlo analysis indicated that the standard error in estimated mean f(S) declined rapidly with increasing sample size. At n = 10, the coefficient of variation in mean f(S) was 7% and at n = 15 it was slightly less than 5%. These observations indicate that radial variation in sap velocity is an important, albeit often overlooked, source of uncertainty in the scaling process. Failure to recognize that not all sapwood is functional in water transport will introduce systematic bias into estimates of both tree and stand water use. Future studies should devise sampling strategies for assessing radial variation in sap velocity and such strategies should be used to identify the magnitude of this variation in a range of non-, diffuse- and ring-porous trees.

Macroscopic characteristics in stems of Castanea creanata x C. sativa

Thirty trees of Castanea crenata x C. sativa from three stands located in Galicia were selected. Both stand and height effect on follows characteristics were studied: thickness and percentage of bark; thickness, rings number and percentage of sapwood; growth rate, green moistue content and wood basic density. Except wood basic density and bark percentage, all the variables studied show significant differences among stands. Height in the stem have no significant effect on growth rate, both thickness and rings number of sapwood, and both percentage and moisture content of bark. At 1.5 m height, average diameter and growth rate show a significant positive correlation coefficient with both bark and sapwood thickness, and they are inversely correlated with bark percentage. No relationship has been found between wood density and growth rate.

Formation and vertical distribution of sapwood and heartwood in Cryptomeria japonica D. Don

The formation and vertical distribution of sapwood and heartwood were studied with a 45-year-old Cryptomeria japonica D. Don. The tree was grown at a plantation with 1.5 m × 3.0 m spacing near Miao-Li, Taiwan and was felled on 27 February 1992. The thickness of sapwood and heartwood was expressed by a ring count and a linear measurement. The east-west (E-W) wood strips were collected from 0.3 m above ground upwards to the top of the tree at 2.5 m intervals. The sapwood thicknesses from the base to the 10.3 m tree level height are around 20–22 growth rings and 42±2 mm. At the top of the tree, the sapwood thickness is narrower. The heartwood, which decreases in thickness with increasing tree level heights is not found at the top of the tree. The heartwood appears as a conical shape in the tree trunk. There is no statistical difference in sapwood/heartwood thickness between E-W aspects. Tree level heights and the tree level age were found to be important parameters in determining the thickness of sapwood/heartwood.

Heartwood, Sapwood, and Fungal Decay Associated with Red-Cockaded Woodpecker Cavity Trees

Provision of suitable sites for red-cockaded woodpecker (Picotdes borealis) cavity excavation is essential for successful management of the woodpecker. To evaluate internal characteristics of pines used by the woodpecker, we increment-cored longleaf pines (Pinus palustris) to determine heartwood diameter, sapwood thickness, and presence of fungal heartwood decay at 1.3, 6.0, 9.0, and 12.0 m aboveground in 53 red-cockaded woodpecker cavity trees and 53 similar control pines in eastern Texas. Red-cockaded woodpecker cavity trees had thinner sapwood and greater heartwood diameter at all heights than did control trees (P 100 years and did not occur with any regularity until pines were >120 years. J. WILDL. MANAGE. 58(4):728-734

Sapwood thickness in Pinuscontorta var. latifolia

The vertical variation in the number of sapwood growth rings and sapwood thickness in Pinuscontorta Dougl. var. latifolia Engelm. was studied in relation to aspect, tree age, bole diameter, sapwood radial growth rate, and whole-xylem radial growth rate. Samples from 19 trees growing on the western slope of the Rocky Mountains near Kamloops, British Columbia, Canada, formed the data base. Sapwood width for individual trees ranged from 20 to 26 mm for both the east and west aspects, and was constant at various heights of the tree bole. Sapwood width for this species was found to be independent of age, diameter, sapwood radial growth rate, and whole-xylem radial growth rate. Sapwood consisted of 25 to 50 growth rings and decreased from the ground level upward to the tree crown. The number of sapwood growth rings was strongly correlated with age, diameter, and radial growth rates for both sapwood and the whole tree. No significant correlation existed between sapwood width and sapwood growth-ring counts.