Equations For Aboveground Biomass Research Articles

Integrated individual tree biomass simultaneous equations for two larch species in northeastern and northern China

Forest biomass estimation at large scale has become an important topic in the background of facing global climate change, and it is fundamental to develop individual tree biomass equations suitable for large-scale estimation. Based on the measured data of biomass components and stem volume from 100 sample trees of two larch species (Larix gmelinii and L. principis-rupprechtii) in northeastern and northern China, an integrated equation system including individual tree biomass equations, stem volume equation and height–diameter regression model were constructed using the dummy variable model and error-in-variable simultaneous equations. In the system, all the parameters of equations were estimated simultaneously, so that the aboveground biomass equation was compatible to stem volume equation and biomass conversion factor (BCF) function; the belowground biomass equation was compatible to root-to-shoot ratio (RSR) function; and stem wood, stem bark, branch and foliage biomass equations were additive to aboveground biomass equation. In addition, the system also ensured the compatibility between one- and two-variable models. The results showed that: (1) whether aboveground biomass equations or belowground biomass equations and stem volume equations, the estimates for larch in northeastern China were greater than those in northern China; (2) BCF of a larch tree decreased with the growing diameter while RSR increased with the growing diameter; (3) the proportion of stem wood biomass to aboveground biomass increased with the growing diameter while those of stem bark, branch, and foliage biomass decreased.

Efficacy of generic allometric equations for estimating biomass: a test in Japanese natural forests

Accurate estimation of tree and forest biomass is key to evaluating forest ecosystem functions and the global carbon cycle. Allometric equations that estimate tree biomass from a set of predictors, such as stem diameter and tree height, are commonly used. Most allometric equations are site specific, usually developed from a small number of trees harvested in a small area, and are either species specific or ignore interspecific differences in allometry. Due to lack of site-specific allometries, local equations are often applied to sites for which they were not originally developed (foreign sites), sometimes leading to large errors in biomass estimates. In this study, we developed generic allometric equations for aboveground biomass and component (stem, branch, leaf, and root) biomass using large, compiled data sets of 1203 harvested trees belonging to 102 species (60 deciduous angiosperm, 32 evergreen angiosperm, and 10 evergreen gymnosperm species) from 70 boreal, temperate, and subtropical natural forests in Japan. The best generic equations provided better biomass estimates than did local equations that were applied to foreign sites. The best generic equations included explanatory variables that represent interspecific differences in allometry in addition to stem diameter, reducing error by 4-12% compared to the generic equations that did not include the interspecific difference. Different explanatory variables were selected for different components. For aboveground and stem biomass, the best generic equations had species-specific wood specific gravity as an explanatory variable. For branch, leaf, and root biomass, the best equations had functional types (deciduous angiosperm, evergreen angiosperm, and evergreen gymnosperm) instead of functional traits (wood specific gravity or leaf mass per area), suggesting importance of other traits in addition to these traits, such as canopy and root architecture. Inclusion of tree height in addition to stem diameter improved the performance of the generic equation only for stem biomass and had no apparent effect on aboveground, branch, leaf, and root biomass at the site level. The development of a generic allometric equation taking account of interspecific differences is an effective approach for accurately estimating aboveground and component biomass in boreal, temperate, and subtropical natural forests.

Cumulative continuous predictions for bole and aboveground woody biomass in Eucalyptus globulus plantations in northwestern Spain

At present there is increasing interest in modelling biomass to estimate carbon sequestration or the availability of forest products for use as bioenergy. The biomass of different tree components can be estimated to provide more detailed information. However, the different components have not been clearly defined. Moreover, the greater the number of components considered, the more difficult it is to fit the system of equations with any guarantee of statistical robustness. To overcome these limitations, we developed a continuous function that predicts cumulative biomass from the stump until any top diameter (including the biomass of branches). We also used two different methods to predict bole biomass: a cumulative continuous biomass function and conversion from volume to biomass by use of a taper equation and average wood density. We used a mixed-effects modelling framework to account for correlated errors in developing the taper equation. We developed a separate equation to estimate the foliar biomass for use in estimating total aboveground tree biomass. The cumulative aboveground woody biomass equation is implicitly additive, and no heteroscedasticity was observed, thereby resolving two of the main modelling goals in the development of biomass equations. For predicting cumulative bole biomass, estimation from volume generated less error, after bias correction, than direct estimation. Moreover, the indirect method also yields useful variables such as volume and height limits. Other variables such as carbon and nutrient contents, calorific power, ash content, etc. can be estimated by multiplying the mean contents by the predicted biomass or, for more accurate predictions, by using equations based on the relative diameter.

Operational biomass recovery of small trees: equations for six central Ontario tree species

Accurate estimates of the amount of biomass that can be recovered at the roadside are needed to make informed decisions about whether to implement an increased utilization harvesting system to supply additional bioenergy feedstocks. Current estimates of recovery are based on total aboveground biomass equations that do not always account for the volume lost to the unharvested stumps or to tops and branches broken during forestry operations. The study took place in a white pine (Pinus strobus L.) mixedwood forest at the Petawawa Research Forest in central Ontario. Equations to describe recoverable biomass were developed from 371 cut and skidded trees, which ranged from 3 to 24 cm in diameter at breast height, across six species. For each species and diameter size class, we evaluated the difference between estimates produced by locally developed equations and those from published equations produced for other locations and forest types. Our recovered biomass estimates were generally higher than the Canadian national averages but within the observed range of published values from across North America. We report that small trees are recovered nearly in their entirety, with little breakage and loss during operations. The high degree of variability among estimates produced by the various equations poses one of the biggest challenges in accurately estimating roadside biomass in an operational setting.

东北地区两个主要树种地上生物量通用方程构建

东北地区两个主要树种地上生物量通用方程构建

Allometric equations, stem density and biomass expansion factors for Cryptomeria japonica in Mount Halla, Jeju Island, Korea

This study was conducted to develop allometric equations and to determine the stem density and biomass expansion factor (BEF) for the estimation of the aboveground and belowground biomass of Cryptomeria japonica in Jeju Island, Korea. A total of 18 trees were harvested from the 40-year-old C. japonica stands in Hannam experimental forest, Jeju Island. The mean biomass of the C. japonica was 50.4 Mg ha in stem wood, 23.1 Mg ha in root, 9.6 Mg ha in branch, 4.6 Mg ha in needle and 4.3 Mg ha in stem bark. The diameter at breast height (DBH) was selected as independent variable for the development of allometric equations. To evaluate the performance of these equations, coefficient of determination (R) and root mean square error (RMSE) were used and results of the evaluation showed that R ranged from 71% (root biomass equation) to 96% (aboveground biomass equation) and the RMSE ranged from 0.10 (aboveground biomass equation) to 0.33 (root biomass equation). The mean stem density of C. japonica was 0.37 g cm and the mean aboveground BEF was 1.28 g g. Furthermore, the ratio of the root biomass to aboveground biomass was 0.32.

English

In forest biomass assessment studies, the selection or development of reliable allometric biomass equations is an essential step which determines largely the accuracy of the resulted biomass estimates. Unfortunately, only few studies on allometric biomass equations have been conducted for peat swamp forests and the results are usually not publicly accessible or well documented. Thus, the objective of this study was to develop site-specific allometric equations for above-ground biomass (AGB) estimations in tropical peat swamp forests in Indonesia. These equations were developed based on 51 destructively sampled trees. The results indicated that the developed site-specific allometric equations have coefficient of determination (R2) greater than 95%. The R2 values ranged from 97.0% to 98.7%, where the lowest R2 value resulted from the simplest model which used only DBH as a predictor. Model 5, which used DBH, H and ρ as predictive variables, provided best performance when estimating the AGB of the study area. Hence, as long as reliable data are available as input, Model 5 is recommended. The accuracy and applicability of the allometric equations for peat swamp forests could be improved further by adding more sampled trees from different tree species and/or with a wider DBH range. Considering the importance of wood density in the estimation of the AGB and the lack of this information for peat swamp forest tree species, research should be dedicated to analysing the wood density of the dominant tree species comprising the majority of the AGB density in the study area.

Developing Site-Specific Allometric Equations for Above-Ground Biomass Estimation in Peat Swamp Forests of Rokan Hilir District, Riau Province, Indonesia

In forest biomass assessment studies, the selection or development of reliable allometric biomass equations is an essential step which determines largely the accuracy of the resulted biomass estimates. Unfortunately, only few studies on allometric biomass equations have been conducted for peat swamp forests and the results are usually not publicly accessible or well documented. Thus, the objective of this study was to develop site-specific allometric equations for above-ground biomass (AGB) estimations in tropical peat swamp forests in Indonesia. These equations were developed based on 51 destructively sampled trees. The results indicated that the developed site-specific allometric equations have coefficient of determination (R2) greater than 95%. The R2 values ranged from 97.0% to 98.7%, where the lowest R2 value resulted from the simplest model which used only DBH as a predictor. Model 5, which used DBH, H and ρ as predictive variables, provided best performance when estimating the AGB of the study area. Hence, as long as reliable data are available as input, Model 5 is recommended. The accuracy and applicability of the allometric equations for peat swamp forests could be improved further by adding more sampled trees from different tree species and/or with a wider DBH range. Considering the importance of wood density in the estimation of the AGB and the lack of this information for peat swamp forest tree species, research should be dedicated to analysing the wood density of the dominant tree species comprising the majority of the AGB density in the study area.

Allometric relationships for volume and biomass for stone pine (Pinus pinea L.) in Italian coastal stands

Abstract: Tree biomass plays a key role in sustainable forest management and in determining forest carbon stocks. Accurate estimates based on species-specific empirical data are necessary for regional and national inventories and forest carbon management. In this study, we obtained allometric relationships for volume and aboveground biomass for stone pine (Pinus pinea) based on empirical data collected in four coastal stands in Italy. Root sampling was also performed. The results enabled generalized equations for volume and aboveground biomass to be developed. However, an analysis also showed several differences in biomass allocation in stone pine resulting from different stand characteristics, emphasizing the importance of stand-dependent factors for adjusting regional or national biomass calculations. Biomass expansion factors were also provided. This study provides tools to help forest managers in quantifying volume and biomass, thereby contributing to the accurate estimation of carbon sequestration and stocks in stone pine stands in Italy.

Canopy volume–aboveground biomass relationships of desert perennials and the effects of elevated CO2

AbstractKnown allometric relationships between aboveground plant biomass and canopy volume allow standing biomass and net primary productivity (NPP) to be estimated non‐destructively. Canopy volume–aboveground biomass relationships are published for many ecosystems, but not for most desert species. It is also unknown if elevated atmospheric carbon dioxide [CO2] affects canopy volume–aboveground biomass relationships in desert perennials, limiting efforts to model NPP in an elevated CO2 environment. We measured canopy volume and aboveground biomass for perennial plants in the Mojave Desert, USA, at the Nevada Desert FACE Facility (NDFF): four species before treatment and 22 species after 10 years (1997–2007) of elevated CO2. Canopy volume to aboveground biomass allometry was estimated for each of the nine most common species individually; the remaining 13 species and unidentified dead shrubs combined to form a single “other” group. The resulting slopes and intercepts, which were estimated using a robust version of major axis regression, were compared across treatments and time points. None of the species had altered allometry in elevated CO2 compared to ambient CO2 treatments, nor did the relationships change over time. Data for each species were therefore combined across treatments and time points to provide the best available predictive equations relating canopy volume and aboveground biomass. The data set contains the canopy volume and aboveground biomass for all 3702 individual plants that were measured. We provide the regression coefficients relating canopy volume to aboveground biomass for both treatment and time comparisons and a single equation that predicts aboveground biomass from canopy volume for each species group. Our results suggest that grasses, forbs, and cacti may increase more rapidly in canopy volume than aboveground biomass, resulting in more shallow slopes compared to woody shrubs. The most notable limitation of this data set is that the maximum plant size at this site may be smaller than at other locations with the same species. The canopy volume to aboveground biomass equations could be improved by adding data from additional locations. Our results suggest that aboveground biomass for desert perennial plants in elevated CO2 conditions may be reasonably estimated from the allometry of plants under ambient CO2.

Intra-specific differences in allometric equations for aboveground biomass of eastern Mediterranean Pinus brutia

Biomass prediction is important when dealing for instance with carbon sequestration, wildfire modeling, or bioenergy supply. Although allometric models based on destructive sampling provide accurate estimates, alternative species-specific equations often yield considerably different biomass predictions. An important source of intra-specific variability remains unexplained. The aims of the study were to inspect and assess intra-specific differences in aboveground biomass of Pinus brutia Ten. and to fill the gap in knowledge on biomass prediction for this species. Two hundred one trees between 2.3 and 55.8 cm in diameter at breast height were sampled throughout the eastern- and southernmost natural distribution area of P. brutia, in Middle East, where it forms different stand structures. Allometric equations were fitted separately for two countries. The differences in biomass prediction at tree, stand, and forest level were analyzed. The effect of stand structure and past forest management was discussed. Between-country differences in total aboveground biomass were not large. However, differences in biomass stock were large when tree components were analyzed separately. Trees had higher stem biomass and lower crown biomass in dense even-aged stands than in more uneven-aged and sparse stands. Biomass and carbon predictions could be improved by taking into account stand structure in biomass models.

Regional aboveground biomass equations for North American arid and semi-arid forests

Calculations of dry tree, plot and regional aboveground biomass, M, and assessments of complex diverse forests remain key challenges in the implementation of conventional and sustainable projects. This study reports a set of robust regional equations and the application of several allometric tree and plot M equations in Mexican arid and semi-arid forest communities. The data were collected from 1084 tree M fitting models, and 195 arid and semi-arid and 206 mesquite trees and 55 plot datasets were used to validate the models. Theoretical, semi-empirical and empirical models with exogenous variables, as well as wood specific gravity, diameter, top height, and form-factor values, were used to evaluate aboveground biomass. Empirical computer-based equations projected more consistently similar tree M assessments than did semi-empirical or theoretical models. Therefore, empirical models are recommended for assessments of tree and plot M, and future allometry research should properly address independent variables in more theoretical models. The large sample size, model richness, economic and ecological importance, and wide coverage of this dataset make it useful for estimating several biogeochemical and bioenergy density parameters and contribute to the body of knowledge regarding heterogeneity in dry forest stand structures.

Establishment of allometric models and estimation of biomass recovery of swidden cultivation fallows in mixed deciduous forests of the Bago Mountains, Myanmar

We established allometric models for fallow forests following swidden cultivation, to estimate biomass accurately in the fallows around a village in the Bago Mountains, Myanmar. By harvesting 160 individual trees from 53 species and 132 sample culms from four bamboo species, allometric equations were determined between tree/culm size variables, such as diameter at breast height (D130) and tree/culm height (H), and plant biomass components such as trunk/culm, branch, and leaf biomass in the fallows. The correlation coefficient for the allometric model for total above-ground tree biomass as a function of D1302H was high (0.956), although the value for leaf biomass was relatively low (0.626). In addition, best-fit allometric relationships for four bamboo species were established. All allometric models involving total above-ground biomass for all bamboo species had significantly high R2 values: 0.817 for G. nigrociliata, 0.877 for B. polymorpha, 0.910 for B. tulda, and 0.963 for D. strictus. A comparison between the present models and previously reported equations for above-ground biomass for tropical forests revealed that our allometric models followed the general trend for biomass estimation, with substantial differences among forest types. In addition, our results suggest that when allometric models are developed using destructive sampling methods, either all mixed species combined or select dominant species can be used, although the optimal approach would include models with all species combined to estimate biomass accumulation for mixed-species forests. Using the best-fit allometric models for trees and bamboo, we estimated tree and bamboo biomass at the community level, supplemented by understory and vine biomass. Biomass accumulation in the study area generally increased with fallow age, with a large contribution of bamboo in the fallows. To estimate biomass of secondary forests accurately, especially fallow forests, relevant allometric relationships and the intensity of swidden cultivation must be considered.

Above-ground biomass estimation at tree and stand level for short rotation plantations of Eucalyptus nitens (Deane & Maiden) Maiden in Northwest Spain

Above-ground allometric biomass and BEF equations were developed in Eucalyptus nitens crops, in age sequence from 2 to 5 years and tree density between 2300 and 5600 ha−1. All models were fitted for crown, stem and total above-ground biomass at tree and stand level and explained a high percentage of data variability (R2adj > 0.90). Biomass Expansion Factors (BEFs) were calculated for all categories and showed great variation, mainly for crown and total biomass. BEFs and stand-tree variable behaviour was analysed to develop BEF models to improve the predictions of constant BEF calculated here. Although all studied variables had significant relationships with BEF, dominant height showed the closest correlation with the crown and total biomass, the equations explaining 99% of biomass variability. Quadratic mean diameter, basal area and age were selected for the stem model. They explained more than 87% of the stem biomass variability. The comparison of the three approaches, biomass and BEF equations and constant BEFs, showed that biomass equations provided the most accurate predictions for stem and total components, followed by BEF equations. Constant BEFs proved the least accurate method for estimating biomass and only provided satisfactory results in relation to stem biomass. In contrast, for the crown component, BEF equations provided slightly more accuracy predictions than biomass equations. The best methodology for biomass production estimation depends on available resources and the level of required accuracy; however, our results suggest that constant BEF should be avoided whenever possible, at least for crown and total aerial biomass.

Improving the accuracy of tree-level aboveground biomass equations with height classification at a large regional scale

A nonlinear simultaneous equations system based on diameter at breast height (DBH), used to ensure additivity for biomass of individual tree components, was fitted for Cunninghamia lanceolata. The data consisted of measurements taken from 600 sample trees in southern China. All sample trees were harvested and measured for biomass of stem wood, stem bark, branches and foliage. Tree height was classified into 2–5 levels based on the height–diameter relationship across a large geographical area. The nonlinear extra sum of squares method and the Lakkis–Jones test were used to evaluate significant differences between biomass equations with DBH only and classified equations and to assess whether height classification had a significant effect on improving the accuracy of the biomass equations. Based on the PRESS residuals, several statistical indicators, e.g. prediction determination coefficient and root mean square error, were used to evaluate model performance. The results show the height classification obviously improved model performance of the fitted equation by increasing the prediction determination coefficient, decreasing root mean square error and reducing bias and absolute bias by DBH class, especially for total aboveground biomass, stem wood biomass and stem bark biomass. Three-levels of height classification was the best for the total aboveground biomass, following by 4-levels, 5-levels and 2-levels. Although statistically significant differences between the classified equations and the equations with DBH only were found for measurements of branch biomass and foliage biomass, their proportions of total aboveground biomass was small and had only a small effect on improving the accuracy of total aboveground biomass estimates. Height classification increased the stability of parameters for the estimation of stem wood and stem bark biomass. The classified biomass equations could be applied to estimate individual tree biomass in the Chinese National Forest Inventory and the method of height classification may be used with other tree species.

Modeling compatible single-tree aboveground biomass equations for masson pine (Pinus massoniana) in southern China

Because of global climate change, it is necessary to add forest biomass estimation to national forest resource monitoring. The biomass equations developed for forest biomass estimation should be compatible with volume equations. Based on the tree volume and aboveground biomass data of Masson pine (Pinus massoniana Lamb.) in southern China, we constructed one-, two- and three-variable aboveground biomass equations and biomass conversion functions compatible with tree volume equations by using error-in-variable simultaneous equations. The prediction precision of aboveground biomass estimates from one variable equation exceeded 95%. The regressions of aboveground biomass equations were improved slightly when tree height and crown width were used together with diameter on breast height, although the contributions to regressions were statistically insignificant. For the biomass conversion function on one variable, the conversion factor decreased with increasing diameter, but for the conversion function on two variables, the conversion factor increased with increasing diameter but decreased with increasing tree height.

Modeling Compatible Single-Tree Aboveground Biomass Equations of Masson Pine (Pinus massoniana) in South China

AbstractIn the background of facing up to the global climate change, it is becoming the inevitable demand to add forest biomass estimation to national forest resource monitoring. The biomass equations to be developed for forest biomass estimation should be compatible with volume equations. Based on the tree volume and aboveground biomass data of Masson pine (Pinus Massoniana Lamb.) in south China, the one, two and three-variable aboveground biomass equations and biomass conversion functions compatible with tree volume equations were constructed using the error-in-variable simultaneous equations in this paper. The results showed: (i) the prediction precision of aboveground biomass estimates from one variable equation was more than 95%; (ii) the regressions of aboveground biomass equations improved slightly when tree height and crown width were used together with diameter on breast height, although the contributions to regressions were statistically significant; (iii) for biomass conversion function on one variable, the conversion factor was decreased with growing diameter, but for conversion function on two variables, the factor was increased with growing diameter while decreased with growing tree height.

Improvement in accuracy of aboveground biomass estimation in Eucalyptus nitens plantations: Effect of bole sampling intensity and explanatory variables

Two sets of aboveground biomass equations were fitted for stem only and stem plus crown predictive variables in Eucalyptus nitens plantations in Northern Spain. A sample of 40 trees was chosen after a complete study of variation in tree height and diameter in the region. The trees were felled and the biomass was divided into the following components: wood, bark, thick branches, thin branches, twigs, leaves and dead branches along the stem. Bole biomass was estimated by systematic subsampling of one 5 cm-thick disk every 0.5 m. Such intensive subsampling enabled determination of the effect of subsampling intensity on accuracy and bias of wood estimation, considering two ratio-type estimators: stem weight to dry matter, determined by the complete weighing (CW) method (i.e. of the fresh weight of the entire stem) and volume to dry matter, determined by the partial weighing (PW) method. The changes in moisture content and basic density along the stem explained the serious risk of dry mass or weight overestimation when a systematic subsample is considered. The average basic density was usually found at a relative height of 30–35% along the stem. The default choice of the bottom disk or log as the first section resulted in overestimations for the CW method and underestimations for the PW one. The biomass equations were fitted by seemingly unrelated regression, with corrections for heteroscedasticity carried out by weighted fitting. Diameter at breast height was the best explanatory variable, and the inclusion of height did not improve the accuracy, except for wood. The inclusion of crown variables improved the predictive ability for crown fractions, increasing the accuracy for estimating thick branches (by 10.8%), twigs (by 19.1%) and leaves (by 17.3%). The biomass of each fraction decreased in the following order: wood > bark > thick branches > dead branches along the stem > leaves > thin branches > twigs. The changes in these percentages with diameter class and the predictive ability of the fitted equations were also studied.

Productivity, aboveground biomass, nutrient uptake and carbon content in fast-growing tree plantations of native and introduced species in the Southern Region of Costa Rica

Early growth performance of four native and two introduced tree species was studied during six years at 13 sites in the southern region of Costa Rica. Selected study sites represent a wide environmental gradient.The selected species were: Pinus caribaea Morelet var hondurensis (Barret y Golfari) and Gmelina arborea Roxb as the introduced species, and Terminalia amazonia (J.F. Gmelin) Exell, Vochysia ferruginea Mart., Vochysia guatemalensis Donn. Sm. and Hieronyma alchorneoides Fr. Allemao. A study about the distribution of aboveground biomass, nutrients and total carbon content of these young plantations by compartments (branches, stem, bark and leaves) was also conducted. Biomass equations for tree compartments were fitted simultaneously using the data corresponding to 24 trees felled. Total export quantities of nutrient from stem and bark biomass were estimated in order to conduct an evaluation of the potential effect of harvesting these species on soil nutrient reserves. The data presented in this study related to plantation growth, aboveground biomass and nutrient concentration and C content by tree compartment, aboveground biomass equations by tree compartment, soil nutrient reserves, stability indices can be used as a reference for: a) selection of tree species vs site characteristics, b) estimation of nutrient export by stem + bark harvesting, c) planning for a second rotation, c) maintenance of site productivity and d) generate better carbon sequestration estimations.

Ontogeny partly explains the apparent heterogeneity of published biomass equations for Fagus sylvatica in central Europe

A set of robust biomass equations was developed for European beech ( Fagus sylvatica), using a large database made of trees from three different European countries. Models were calibrated on the French control dataset, including a broad range of tree size, age and geographical conditions. Their independent validation on Belgian, German unfertilized, German and French fertilized stands gave very promising unbiased results for all of the main tree compartments. The basic fitted allometric equation (biomass = β × ( d 2 h) γ ) allowed us to work with biologically meaningful parameters, where β encompasses both the form of the tree and the wood density, and γ is the allometric exponent that indicates the proportionality between the biomass and volume relative increments. The allometric parameters were found to vary with stand age (decreasing for the crown and increasing for the bole), and introducing these parameters to the equations significantly improved the performance of all aboveground biomass equations. This age effect was related to changes in both stem form and wood density for the trunk and to changes in hydraulic conductance for the crown. We argue that introducing stand age into the predictive parameters is the key for the accuracy of our equations. Management options and stand fertility stand for the low residual variations around this relationship. To confirm this result, we were able to homogenize most of the published biomass equations by accounting for the stand age given in each original paper. We noticed that our results were consistent with and matched the patterns that were observed for Eucalyptus ( Eucalyptus). This could mean that species with similar wood properties and crown architecture may exhibit similar biomass equation structures.