Search

Background and aims: Coastal wetland types have been severely altered by human reclamation activities and Spartina alterniflora invasion. However, how these changes impact C-N-P stoichiometry and nutrient allocation of coastal plants remain unclear. Methods: We investigated C, N, and P contents and ratios in leaf, stem, and root from 30 sites with adjacent natural wetlands (as control, dominated by native Phragmites australis), reclaimed wetlands (dominated by native P. australis), and invasive wetlands (dominated by exotic S. alterniflora) across eastern coast of China. Results: C content and N:P ratio remained constant, N and P contents decreased significantly, but C:N and C:P ratios increased with increasing latitude in natural wetlands. While the direction or magnitude of these latitudinal patterns in reclaimed and invasive wetlands were extremely changed at both individual and organ level. Interestingly, leaf had significant higher C, N, and P contents but lower C:N and C:P ratios than stem and root in each wetland. Compared with natural wetlands, both reclaimed and invasive wetlands had significant lower C and N contents and N:P ratio but higher C:N ratio, invasive wetlands also had significant higher leaf P content. P. australis enhanced the homeostasis for N:P, strength allometric relationship of N and P in leaf, but exhibited a isometric relationship of N and P at individual level after reclamation. S. alterniflora had strict homeostasis for N, P and N:P in most organs and strong ability to decouple the allometric relationship of N and P in leaf, and N changed faster than P at individual level. Conclusions: Importantly, large-scale observations showed that reclamation and especially S. alterniflora invasion significantly decreased N:P ratio in each organ, which might highly affect below- and above-ground trophic chains in the future. Our study provides practical insights in understanding species-specific and multiorgan biogeochemical process and the nutrient allocation strategies of plants under reclaimed and invasive pressures in coastal salt marshes. [ABSTRACT FROM AUTHOR]

Tree allometry plays a crucial role in tree survival, stability, and timber quantity and quality of mixed-species plantations. However, the responses of tree allometry to resource utilisation within the framework of interspecific competition and complementarity remain poorly understood. Taking into consideration strong- and weakspace competition (SC and WC), as well as N2-fixing and non-N2-fixing tree species (FN and nFN), a mixed-species planting trial was conducted for Betula alnoides, a pioneer tree species, which was separately mixed with Acacia melanoxylon (SC + FN), Erythrophleum fordii (WC + FN), Eucalyptus cloeziana (SC + nFN) and Pinus kesiya var. langbianensis (WC + nFN) in southern China. Six years after planting, tree growth, total nitrogen (N) and carbon (C) contents, and the natural abundances of 15N and 13C in the leaves were measured for each species, and the mycorrhizal colonisation rates of B. alnoides were investigated under each treatment. Allometric variations and their relationships with space competition and nutrient-related factors were analyzed. The results showed a consistent effect of space competition on the height-diameter relationship of B. alnoides in mixtures with FN or nFN. The tree height growth of B. alnoides was significantly promoted under high space competition, and growth in diameter at breast height (DBH), tree height and crown size were all expedited in mixtures with FN. The symbiotic relationship between ectomycorrhizal fungi and B. alnoides was significantly influenced by both space competition and N2 fixation by the accompanying tree species, whereas such significant effects were absent for arbuscular mycorrhizal fungi. Furthermore, high space competition significantly decreased the water use efficiency (WUE) of B. alnoides, and its N use efficiency (NUE) was much lower in the FN mixtures. Structural equation modeling further demonstrated that the stem allometry of B. alnoides was affected by its NUE and WUE via changes in its height growth, and crown allometry was influenced by the mycorrhizal symbiotic relationship. Our findings provide new insights into the mechanisms driving tree allometric responses to above- and belowground resource competition and complementarity in mixed-species plantations, which are instructive for the establishment of mixed-species plantations. [ABSTRACT FROM AUTHOR]

Exploring the allometric relationship between carbon emission and economic development can provide guidance for policy-makers who hope to accelerate carbon emission reduction and achieve high-quality development. First, based on the established DMSP/OLS and NPP/VIIRS nighttime light datasets, this study simulated the carbon emissions of the Yangtze River Delta from 2000 to 2020. Second, our research analyzed the spatiotemporal evolution characteristics of carbon emissions. Third, adopting allometric growth model, we explored the allometric relationship between economic development and carbon emissions in Yangtze River Delta. The main conclusions are as follows. First, four prediction models, namely, linear fitting, support vector machine, random forest, and CNN-BiLSTM deep learning, were compared to simulate the accuracy of carbon emissions. Consequently, the CNN-BiLSTM deep learning estimation model presented the best accuracy. Second, both the carbon emissions in YRD as a whole showed an increasing trend, with the largest growth rate appearing in Shanghai and the smallest growth rate occurring in Lishui. Moreover, the high-carbon emission areas were mainly distributed in the core city cluster, which are enclosed by Shanghai, Nanjing, and Hangzhou. Finally, the allometric relationship between economic development and carbon emissions was dominated by one-level negative during the sample period, and the relative growth rate of carbon emissions is lower than that of the economic development, which made the YRD at a basic coordinate stage of weak expansion of economy. [ABSTRACT FROM AUTHOR]

The cortex (i.e., absorptive tissue) and stele (transportive vascular tissue) are fundamental to the function of plant roots. Unraveling how these anatomical structures are assembled in absorptive roots is essential for our understanding of plant ecology, physiology, and plant responses to global environmental changes. In this review, we first compile a large data set on anatomical traits in absorptive roots, including cortex thickness and stele radius, across 698 observations and 512 species. Using this data set, we reveal a common root allometry in absorptive root structures, i.e., cortex thickness increases much faster than stele radius with increasing root diameter (hereafter, root allometry). Root allometry is further validated within and across plant growth forms (woody, grass, and liana species), mycorrhiza types (arbuscular mycorrhiza, ectomycorrhiza, and orchid mycorrhizas), phylogenetic gradients (from ferns to Orchidaceae), and environmental change scenarios (e.g., elevation of atmospheric CO2 concentration and nitrogen fertilization). These findings indicate that root allometry is common in plants. Importantly, root allometry varies greatly across species. We then summarize recent research on the mechanisms of root allometry and potential issues regarding these mechanisms. We further discuss ecological and evolutionary implications of root allometry. Finally, we propose several important research directions that should be pursued regarding root allometry.

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cortex radius (CR) and stele radius (SR) are important functional traits associated with the nutrient acquisition and transport functions of fine roots, respectively. However, for developmental and anatomical reasons, the resource acquisition–transport relationship of fine roots is expected to be different for different root orders. To address this issue, critical fine root anatomical traits were examined for the first three orders of roots of 59 subtropical woody plants. Designating the most distal fine roots as order one, SR scaled isometrically with respect to root radius (RR) (i.e., SR ∝ RR1.0) in the three root orders, whereas CR scaled allometrically with respect to RR (i.e., CR ∝ RR>1.0) with the numerical values of scaling exponents increasing significantly with increasing root orders thereby indicating a disproportional increase in CR with increasing root orders. There were also differences between normalized root tissue (CR/RR and SR/RR) and RR in different root orders. A negative isometric relationship (i.e., SR/RR ∝ RR−1.0) existed between SR/RR and RR in three order roots, whereas the allometric exponent between CR/RR and RR increased with root order (from 0.88 to 1.55). Collectively, the data indicate that root anatomical and functional traits change as a function of RR and that these changes need to be considered when modeling fine root resource acquisition–transport functions. [ABSTRACT FROM AUTHOR]

Accurate estimates of tree height (H) are critical for forest productivity and carbon stock assessments. Based on an extensive dataset, we developed a set of generalized mixed-effects height–DBH (H–D) models in a typical natural mixed forest in Northeastern China, adding species functional traits to the H–D base model. Functional traits encompass diverse leaf economic spectrum features as well as maximum tree height and wood density, which characterize the ability of a plant to acquire resources and resist external disturbances. Beyond this, we defined expanded variables at different levels and combined them to form a new model, which provided satisfactory estimates. The results show that functional traits can significantly affect the H–D ratio and improve estimations of allometric relationships. Generalized mixed-effects models with multilevel combinations of expanded variables could improve the prediction accuracy of tree height. There was an 82.42% improvement in the accuracy of carbon stock estimates for the studied zone using our model predictions. This study introduces commonly used functional traits into the H–D model, providing an important reference for forest growth and harvest models. [ABSTRACT FROM AUTHOR]

Carbon (C), nitrogen (N), and phosphorus (P) stoichiometry and their allometric relationships in soil and plants are hot topics that attract a lot of attention, while those rocks that form soils are often neglected. Weathering is a common geological phenomenon that may significantly influence the nutrient composition and release of nutrients from rock and its inherent soils. This study presents C, N, and P concentrations data as well as microscope petrological photographs of fresh and weathered sandstones from Longhushan World Geopark in SE China, in an attempt to investigate C, N, and P stoichiometry of rocks before and after weathering and discuss the driving mechanisms. The results show that weathering significantly decreased rock C, C/N, and C/P concentrations, slightly decreased N and N/P concentrations, and slightly increased P concentration. Microscope observations show that fresh sandstones contain calcite, apatite, microplagioclase, and organic matter, while weathered sandstones feature apatite and organic matter. The flexible allometric relationships and mineral changes before and after rock weathering indicate that chemical mechanisms, such as dissolution of carbonate and hydration of microplagioclase, have changed the existence form of C, N, P and, thus, significantly influence rock C, N, and P stoichiometry. This stoichiometry feature can be in turn used to reflect the regulation effect of rock weathering. [ABSTRACT FROM AUTHOR]

Copyright of Naturaliste Canadien is the property of La Societe Provancher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Allometric growth equations help to describe the correlation between the variables of tree biological characteristics (e.g., diameter and height, diameter and canopy width) and estimate tree dynamics at a given tree dimension. Allometric models of common tree species within urban forests are also important to relate ecosystem services to common urban tree measurements such as stem diameter. In this study, allometric growth models were developed for common tree species used for urban greening on the streets of seven municipal districts in Qingdao city of eastern China. A sampling survey was constructed on an urban–rural gradient to obtain the data of tree diameter, crown width, height to live crown base, and tree height. From these measurements, the crown volume and crown projection area of tree species were calculated. The allometric relationship between two variables was established using quantile regression models (95%, 50%, and 5%) to explore its correlation and the influence of tree species characteristics on urban tree allometry. Our results showed that the correlation of allometric growth of different tree species varied largely due to their own characteristics, and the allometric growth of the same tree species was significantly different as well under the fitting of different quantiles. We found that the relationship between crown width and diameter was stronger than that between tree height and diameter. Moreover, the allometric relationship between crown projection area–diameter and crown width–diameter showed similar fitting. The allometric relationship analysis provide theoretical models and a way to use common field data to support urban forestry management and for the subsequent evaluation and prediction of tree functions and ecosystem services. [ABSTRACT FROM AUTHOR]

Understanding how a plant allocates biomass for reproduction and the effect of location position on twigs' biomass partitioning provides essential information on how to maximise fruit yields through pruning. Fengdan (Paeonia ostii) is a variety of oil Peony newly developed in China. In this paper, the pattern of biomass allocation and allometric growth of the modules within twig (fruit twigs) of five populations of Fengdan were investigated by using standardised major axis (SMA) analyses. The ANOVA results showed that the biomass of stem, seed, husk and fruit per twig significantly varied among populations and among twigs growing at different positions within an individual plant. The top twig had the largest stem and fruit biomass. Twig showed an allometric growth relationship between reproduction and growth (SMA slope b ≠ 1). An obvious trade‐off was found between seed number and 100‐seed weight in fruits. These findings demonstrate that the seated position of the Fengdan twig significantly influences its resource allocation pattern and fruit (seed) yield, implying the efficiency of creating a suitable growth environment and optimising tree architecture in increasing oil Peony yield. [ABSTRACT FROM AUTHOR]

Biomass of seedlings at different developing stages of growth is important information for studying the response of species to site conditions. The objectives of this study was to explore the distribution characteristics of AGB (above-ground biomass) and BGB (below-ground biomass) of Abies georgei var. smithii seedlings of different ages, and investigate the effects of topography (slope aspect, altitude), plant community characteristics (crown density, species diversity, etc.), and soil properties (soil physical and chemical properties) on the biomass and its allocation. Seedlings in five age classes (1–2, 3–4, 5–6, 7–8, and 9–10 years old) were collected by full excavation from 6 elevations (3800 m, 3900 m, 4000 m, 4100 m, 4200 m, 4300 m) on the north and south slopes of Sejila Mountain in Tibet. 15 seedlings of each age class were investigated at one altitude. The individual effects of seedling age (SA) and the interaction effects of SA, slope aspect (SL), and elevation (EG), namely, SL×EG, SL×SA, EG×SA, and SL×EG×SA, had significant effects on the AGB of the seedlings (p<0.05), whereas BGB was only significantly affected by SA (p<0.001). The AGB and BGB of the seedlings showed a binomial growth trend with the increase in seedling age, and had an allometric relationship at different elevations, α (allometric exponential) varied from 0.913 to 1.046 in the northern slope, and from 1.004 to 1.268 in the southern slope. The biomass of seedlings on the northern slope was remarkably affected by stand factors, with a contribution rate of 47.8%, whereas that on the southern slope was considerably affected by soil factors with a contribution rate of 53.2%. The results showed that age was the most important factor affecting seedling biomass. The allometric pattern of seedling biomass was relatively stable, but in a high-altitude habitat, A. georgei var. smithii seedlings increased the input of BGB. Understanding seedling biomass allocation and its influencing factors is useful for evaluating plants' ability to acquire resources and survival strategies for adaptation to the environment in Tibet Plateau. [ABSTRACT FROM AUTHOR]

Background – Shrublands are receiving increasing attention because of climate change. However, knowledge about biomass allocation of shrublands at the community level and how this is regulated by climate is of limited availability but critical for accurately estimating carbon stocks and predicting global carbon cycles. Methods – We sampled 50 typical shrublands along a climate gradient in China and investigated the biomass allocation of shrubland at the community level and the effect of climate on biomass allocation. Shrub biomass was estimated using species-specific allometric relationships and the biomass of understory herbs was collected by excavating the whole plant. Regression analysis was used to examine the relationships between the biomass and the climate factors. RMA were conducted to establish the allometric relationships between the root and the shoot biomass at the community level.Key results – Shoot, root, and total biomass of shrub communities across different sites were estimated with median values of 206.5, 145.8, and 344.5 g/m2, respectively. Shoot, root, and total biomass of herb communities were estimated at 68.2, 58.9, and 117.2 g/m2, respectively. The median value of the R/S ratio of shrub communities was 0.58 and that of herb communities was 0.84. The R/S ratio of the shrub community showed a negative relationship with mean annual temperature and mean annual precipitation and a positive relationship with total annual sunshine and the aridity index. The R/S ratio of the herb community however showed a weak relationship with climate factors. Shoot biomass of the shrub community was nearly proportional to root biomass with a scaling exponent of 1.17, whereas shoot biomass of the herb community was disproportional to root biomass with a scaling exponent of 2.1.Conclusions – In shrublands, root biomass was more affected than shoot biomass by climate factors and this is related to water availability as a result of biomass allocation change of the shrub community. The understory herb community was less affected by climate due to the modification of the overstory–understory interaction to the climate-induced biomass allocation pattern. Shoot biomass of shrubs scales isometrically with root biomass at the community level, which supports the isometric theory of above-ground and below-ground biomass partitioning.

The determination the forced vital capacity (FVC) and the forced expiratory volume in 1 second (FEV1) during spirometry studies, is at the core of the evaluation of the pulmonary function of patients with respiratory diseases. The Global Lung Function Initiative (GLI) offers the most extensive data set of normal lung functions available, which is currently used to determine the average expected/predicted FEV1 and FVC (pred V), and their lower limit of normal (LLN, 5th percentile) at any given height and age for women and men. These prediction equations are currently expressed in a rather complex form: pred V = exp [p+ (a x Ln (height) + (n x Ln (age)) + spline] and LLN = exp(Ln (pred V) + Ln (1 – 1.645 x S x CV)/S) ; and are currently used to generate interpretations in commercialized spinographic system. However, as shown in this paper, these equations contain physiological and fundamental allometric information on lung volumes that become obvious when rewriting mean predicted values as a "simple" power function of height and LLN as a percentage of the mean predicted values. We therefore propose to present the equations of prediction obtained from the GLI data using simplified expressions in adults (18–95 years old) to reveal some of their physiological and allometric meaning. Indeed, when predicted FEV1 and FVC (pred V) were expressed under the form pred V= αx height a x b(age), the resulting exponent (a) ranges between 2 and 3, transforming the one dimension of a length (size) into a volume , akin to the third-order power (cubic) function of height historically used to predict lung volumes. Only one function, b (age), is necessary to replace all the factors related to age, including the tables of discrete data of spline functions original equations. Similarly, LLN can be expressed as LLN = c (age) x pred V to become a simple percentage of the predicted values, as a function of age. The equations with their respective new polynomial functions were validated in 52,764 consecutive spirometry tests performed in 2022 in 22,612 men and 30,152 women at the Cleveland Clinic. Using these equations, it become obvious that for both women and men, FEV1/FVC ratio decreases with the size as the exponent of the power function of height is lower for FEV1 than FVC. We conclude that rewriting the GLI predicted equations with simpler formulations restitutes to the GLI data some of their original allometric meaning, without altering the accuracy of their prediction. • The Global Lung Function Initiative (GLI) offers the most extensive data set of normal lung functions available, which is currently used to determine the average expected/predicted FEV1 and FVC (pred V), and their lower limit of normal (LLN, 5th percentile). • Rewriting the GLI predicted equations as a power function of height gives to the GLI data a unique physiological and allometric meaning. [ABSTRACT FROM AUTHOR]

Accurate estimates of forest aboveground biomass (AGB) are essential for global carbon cycle studies and have widely relied on approaches using spectral and structural information of forest canopies extracted from various remote sensing datasets. However, combining the advantages of active and passive data sources to improve estimation accuracy remains challenging. Here, we proposed a new approach for forest AGB modeling based on allometric relationships and using the form of power-law to integrate structural and spectral information. Over 60 km² of drone light detection and ranging (LiDAR) data and 1,370 field plot measurements, covering the four major forest types of China (coniferous forest, sub-tropical broadleaf forest, coniferous and broadleaf-leaved mixed forest, and tropical broadleaf forest), were collected together with Sentinel-2 images to evaluate the proposed approach. The results show that the most universally useful structural and spectral metrics are the average values of canopy height and spectral index rather than their maximum values. Compared with structural attributes used alone, combining structural and spectral information can improve the estimation accuracy of AGB, increasing R² by about 10% and reducing the root mean square error by about 22%; the accuracy of the proposed approach can yield a R² of 0.7 in different forests types. The proposed approach performs the best in coniferous forest, followed by sub-tropical broadleaf forest, coniferous and broadleaf-leaved mixed forest, and then tropical broadleaf forest. Furthermore, the simple linear regression used in the proposed method is less sensitive to sample size and outperforms statistically multivariate machine learning-based regression models such as stepwise multiple regression, artificial neural networks, and Random Forest. The proposed approach may provide an alternative solution to map large-scale forest biomass using space-borne LiDAR and optical images with high accuracy. [ABSTRACT FROM AUTHOR]

Abstract Background Larch (Larix Mill.) forests are widely distributed in the upper parts of mountainous areas in China, playing vital roles in constructing mountain landscapes and maintaining mountain environments. Despite their importance, our knowledges on the large-scale patterns of structure characteristics and the relationships between different structure variables are unclear. In this paper, we investigated 155 plots from 11 natural larch forest types across the country to explore the biogeographic patterns of the structure characteristics and the allometric relationships between different structure variables for Chinese larch forests. Results The structure characteristics were significantly different among larch forest types. For different larch forest types, the power function fits the relationships between tree height and diameter at breast height (DBH), average DBH and stem density, and taper and stem density well, but with different exponents among larch forest types. The power exponents of the allometric relationships between tree height and DBH for different larch forest types varied from 0.61 to 0.93 (mean = 0.86) by standard major axis regression (SMA), and from 0.51 to 0.78 (mean = 0.56) by ordinary least square regression (OLS). The 50%, 75% and 95% quantile regression (QR) and OLS indicated that the average DBH and taper of the L. gmelinii forests, L. gmelinii var. principis-rupprechtii forests, and L. sibirica forests were significantly correlated with stem density. Conclusions The relationship between tree height and DBH showed a power function relationship for all larch forest types in China, but with different exponents. Overall, stem density was negatively correlated with average DBH and taper. The Sect. Larix forests exhibited stand density effect. Our findings provide an important basis for recognizing the biogeographic patterns of structure factors and for the management of larch forests in China.

The petiole–lamina relationship is central to the functional tradeoff between photosynthetic efficiency and the support/protection cost. Understanding environmental gradients in the relationship and its underlying mechanisms remains a critical challenge for ecologists. We investigated the possible scaling of the petiole–lamina relationships in three dimensions, i.e., petiole length (PL) vs. lamina length (LL), petiole cross sectional area (PCA) vs. lamina area (LA), and petiole mass (PM) vs. lamina mass (LM), for 325 Qinghai–Tibetan woody species, and examined their relation to leaf form, altitude, climate, and vegetation types. Both crossspecies analysis and meta-analysis showed significantly isometric, negatively allometric, and positively allometric scaling of the petiole–lamina relationships in the length, area, and mass dimensions, respectively, reflecting an equal, slower, and faster variation in the petiole than in the lamina in these trait dimensions. Along altitudinal gradients, the effect size of the petiole–lamina relationship decreased in the length and mass dimensions but increased in the area dimension, suggesting the importance of enhancing leaf light-interception and nutrient transport efficiency in the warm zones in petiole development, but enhancing leaf support/protection in the cold zones. The significant additional influences of LA, LM, and LA were observed on the PL–LL, PCA–LA, and PM–LM relationships, respectively, implying that the single-dimension petiole trait is affected simultaneously by multidimensional lamina traits. Relative to simple-leaved species, the presence of petiolule in compound-leaved species can increase both leaf light interception and static gravity loads or dynamic drag forces on the petiole, leading to lower dependence of PL variation on LL variation, but higher biomass allocation to the petiole. Our study highlights the need for multidimension analyses of the petiole–lamina relationships and illustrates the importance of plant functional tradeoffs and the change in the tradeoffs along environmental gradients in determining the relationships. [ABSTRACT FROM AUTHOR]

The petiole–lamina relationship is central to the functional tradeoff between photosynthetic efficiency and the support/protection cost. Understanding environmental gradients in the relationship and its underlying mechanisms remains a critical challenge for ecologists. We investigated the possible scaling of the petiole–lamina relationships in three dimensions, i.e., petiole length (PL) vs. lamina length (LL), petiole cross sectional area (PCA) vs. lamina area (LA), and petiole mass (PM) vs. lamina mass (LM), for 325 Qinghai–Tibetan woody species, and examined their relation to leaf form, altitude, climate, and vegetation types. Both crossspecies analysis and meta-analysis showed significantly isometric, negatively allometric, and positively allometric scaling of the petiole–lamina relationships in the length, area, and mass dimensions, respectively, reflecting an equal, slower, and faster variation in the petiole than in the lamina in these trait dimensions. Along altitudinal gradients, the effect size of the petiole–lamina relationship decreased in the length and mass dimensions but increased in the area dimension, suggesting the importance of enhancing leaf light-interception and nutrient transport efficiency in the warm zones in petiole development, but enhancing leaf support/protection in the cold zones. The significant additional influences of LA, LM, and LA were observed on the PL–LL, PCA–LA, and PM–LM relationships, respectively, implying that the single-dimension petiole trait is affected simultaneously by multidimensional lamina traits. Relative to simple-leaved species, the presence of petiolule in compound-leaved species can increase both leaf light interception and static gravity loads or dynamic drag forces on the petiole, leading to lower dependence of PL variation on LL variation, but higher biomass allocation to the petiole. Our study highlights the need for multidimension analyses of the petiole–lamina relationships and illustrates the importance of plant functional tradeoffs and the change in the tradeoffs along environmental gradients in determining the relationships.

Background: Larch (Larix Mill.) forests are widely distributed in the upper parts of mountainous areas in China, playing vital roles in constructing mountain landscapes and maintaining mountain environments. Despite their importance, our knowledges on the large-scale patterns of structure characteristics and the relationships between different structure variables are unclear. In this paper, we investigated 155 plots from 11 natural larch forest types across the country to explore the biogeographic patterns of the structure characteristics and the allometric relationships between different structure variables for Chinese larch forests. Results: The structure characteristics were significantly different among larch forest types. For different larch forest types, the power function fits the relationships between tree height and diameter at breast height (DBH), average DBH and stem density, and taper and stem density well, but with different exponents among larch forest types. The power exponents of the allometric relationships between tree height and DBH for different larch forest types varied from 0.61 to 0.93 (mean = 0.86) by standard major axis regression (SMA), and from 0.51 to 0.78 (mean = 0.56) by ordinary least square regression (OLS). The 50%, 75% and 95% quantile regression (QR) and OLS indicated that the average DBH and taper of the L. gmelinii forests, L. gmelinii var. principis-rupprechtii forests, and L. sibirica forests were significantly correlated with stem density. Conclusions: The relationship between tree height and DBH showed a power function relationship for all larch forest types in China, but with different exponents. Overall, stem density was negatively correlated with average DBH and taper. The Sect. Larix forests exhibited stand density effect. Our findings provide an important basis for recognizing the biogeographic patterns of structure factors and for the management of larch forests in China. [ABSTRACT FROM AUTHOR]

Triploid organisms, in particular oysters, are widely used in marine aquaculture. However, the advantage of triploid oysters compared to diploids has not been proven in all cases. Comparative morphological analysis of Pacific oysters Crassostrea gigas of different ploidy levels allows evaluating the benefits of raising triploids in the Black Sea. First, the morphological characteristics of diploid and triploid Pacific oysters C. gigas farmed in the Black Sea were studied. Allometric ratios of weight (W, g) and shell height (H, mm) of oysters were obtained, which are described by the equations W2n = 4 x 10-4 x H2n 2.56, R² = 0.86 and W3n = 9 x 10-5 x H3n 2.90, R² = 0.91. Triploids showed positive allometry and had more biomass at smaller shell height than diploid oysters. A clear linear relationship of the height and length of oyster shells was established. Significant differences in linear parameters between 2n and 3n C. gigas farmed in Donuzlav Liman are not seen. Based on these results, it is assumed that the advantage of the growth of 3n mollusks is less evident in farms located at high latitudes. The environmental factors and farm technology have probably affected the growth of oysters to a greater degree than their ploidy. [ABSTRACT FROM AUTHOR]

Flightless birds were once the largest and heaviest terrestrial fauna on many archipelagos around the world. Robust approaches for estimating their population parameters are essential for understanding prehistoric insular ecosystems and extinction processes. Body mass and population density are negatively related for extant flightless bird species, providing a method for quantifying densities and population sizes of extinct flightless species. Here we assemble an updated global data set of body mass and population densities for extant flightless birds and estimate the relationship between these variables. We use generalised least squares models that account for phylogenetic relatedness and incorporate the effects of limiting factors (e.g. habitat suitability) on population density. We demonstrate the applicability of this allometric relationship to extinct species by estimating densities for each of the nine species of moa (Dinornithiformes) and generating a combined spatially explicit map of total moa density across New Zealand. To compare our density estimates with those previously published, we summed individual species' abundances to generate a mean national density of 2.02–9.66 birds km−2 for low‐ and high‐density scenarios, respectively. Our results reconcile the extreme bimodality of previous estimates (< 2 birds km−2 and > 10 birds km−2) and are comparable to contemporary densities of large herbivorous wild mammals introduced into New Zealand about 150 yr ago. The revised moa density has little effect on the harvest rates required to bring about extinction within 150–200 yr, indicating that rapid extinction was an inevitable response to human hunting, irrespective of the initial population of moa. [ABSTRACT FROM AUTHOR]

Morphometric analysis of Austruca iranica population from the two different sites of Sandspit (Karachi, Pakistan) mangrove area was examined. Total seven growth related traits: carapace length (CL), carapace width (CW), enlarged chela length (En.Ch.L), enlarged chela width (En.Ch.W), abdominal length (Ab.L), abdominal width (Ab.W) and pleopod length (Pl.L= in male) examined for the relative growth analysis. Carapace width (CW) used as independentt variable to observe relationship between all the stated growth related traits. A total of 1,244 crabs were collected from both sites; among them 566 males and 628 females. Descript analysis showed (CW) ranged from (male = 3.5 mm to 18 mm) and (female = 2.5 mm to 16 mm) from station 1 and (male = 4.00 mm to 18.5 mm) and (female = 3.5 mm to 18 mm) from station 2. The overall sex ratio (p < 0.05) skewed in favor of females (0.91: 1.0) during South West Monsoon (SWM) season. Relationship between carapace length and carapace width showed positive allometric relation (R²=92.1%) in males. The females showed positive allometric relationship from carapace length and abdominal width (R²= 89.6 %). Overall significant difference observed in both males and females through size at sexual maturity from both sites. The logistic equation indicated that individuals reach at sexual maturity when they attain (male: CW50=6.65mm; female: CW50=6.20mm) from station 1 and (male: CW50=8.20mm; female: CW50=6.30mm) from station 2. [ABSTRACT FROM AUTHOR]

Floral and seed traits, their relationships, and responses to abiotic constraints are considered the key determinants of the invasion success of non-native plant species. However, studies evaluating the pattern of floral and seed traits of non-native species in mountain ecosystems are lacking. In this study, we determined (a) whether the floral and seed traits of native and non-native species show similarity or dissimilarity across elevations in mountains, and (b) whether the non-native species follow different allometric patterns compared with native species. Functional variations between native and non-native species were assessed through floral and seed traits: flower count, flower display area, flower mass, specific flower area, seed count, and seed mass across an elevational gradient. Permanent plots (20 × 20 m) were laid at each 100 m elevation rise from 2000 to 4000 m a.s.l. for sampling of herbaceous plant species. The mean values of floral and seed traits such as flower display area, specific flower area, and seed count were significantly higher for non-native species compared to native species. A significant difference in trait values (flower display area, flower mass, seed count, and seed mass) between non-native species and native species was observed along the elevational gradient, except for flower count and specific flower area. The bivariate relationship revealed non-native species to exhibit a stronger relationship between flower display area ∼ flower mass, and flower display area ∼ seed mass traits than the native species. Non-native species showed enhanced reproductive ability under varying environmental conditions along an elevational gradient in mountain ecosystems. Greater flower display area and seed mass at lower elevations and a stronger overall trait-trait relationship among non-native species implied resource investment in pollinator visualization, flower mass, and seed quality over seed quantity. The study concludes that enhanced plasticity and reproductive fitness of floral and seed traits would consequently aid non-native species to adapt, become invasive, and displace native species in mountain ecosystems if the climatic barriers acting on non-native species are reduced with climate change. • Studied floral and seed traits of native and non-native species in mountain ecosystems. • Floral and seed traits exhibited significant differences between non-native and native plants. • Bivariate scaling relationships exhibited stronger allometric relationships for non-natives. • Non-natives showed enhanced reproductive ability along an elevational gradient. • Enhanced reproductive traits facilitate non-natives to adapt in mountains. [ABSTRACT FROM AUTHOR]

In forest ecosystem studies, tree stem structure variables (SSVs) proved to be an essential kind of parameters, and now simultaneously deriving SSVs of as many kinds as possible at large scales is preferred for enhancing the frontier studies on marcoecosystem ecology and global carbon cycle. For this newly emerging task, satellite imagery such as WorldView-2 panchromatic images (WPIs) is used as a potential solution for co-prediction of tree-level multifarious SSVs, with static terrestrial laser scanning (TLS) assumed as a ‘bridge’. The specific operation is to pursue the allometric relationships between TLS-derived SSVs and WPI-derived feature parameters, and regression analyses with one or multiple explanatory variables are applied to deduce the prediction models (termed as Model1s and Model2s). In the case of Picea abies, Pinus sylvestris, Populus tremul and Quercus robur in a boreal forest, tests showed that Model1s and Model2s for different tree species can be derived (e.g. the maximum R2 = 0.574 for Q. robur). Overall, this study basically validated the algorithm proposed for co-prediction of multifarious SSVs, and the contribution is equivalent to developing a viable solution for SSV-estimation upscaling, which is useful for large-scale investigations of forest understory, macroecosystem ecology, global vegetation dynamics and global carbon cycle.

Knowing the allometric relationship between the total height and the diameter (At-d) is an important technical tool to reduce times and costs in the realization of timber forest inventories; in addition, it gives certainty to volume estimates in a management plan. Quintana Roo, Mexico, has timber species of commercial importance and it is necessary to represent this relationship, therefore, the objective was to fit At-d models for trees of Bucida buceras (pukté) under the mixed effects approach. A sample of 996 trees measured in the National Forestry and Soil Inventory 2004-2009 was processed and the Schumacher model was fitted under ordinary least squares (OLS) and mixed effects model (MEM), where the control of variability was performed by groupings using three classification criteria: cup diameter class, average cup diameter and by conglomerate. Each grouping criterion was considered as an independent level. When comparing the fit of the MCO model against that of MEM, it was determined that the best values in the Akaike and Bayesian Information Criteria were presented by the MEM approach. The fit was higher when grouped by conglomerate (Pseudo-R2 = 0.346, approach classic, Pseudo-R2 = 0.815, mixed effects) with a bias of -0.46 m. The proposed model is reliable to estimate the At as a function of d for this species in the tropical forests of Quintana Roo. [ABSTRACT FROM AUTHOR]

The morphological structures of organisms may be subject to divergence when exposed to varied nutritive conditions, due to the occurrence of developmental plasticity and its fixation due to the process of genetic accommodation. The allometric relationship of traits with respect to each other and to the whole body defines the shape of an individual. Developmental plasticity in different nutritional regimes affects the absolute value of traits and its relative scaling with respect to body size. We investigated the diversification in wing dimensions and body size in Drosophila ananassae by utilizing isofemale lines of Bilaspur and karyotypically characterized stocks of Varanasi, by rearing flies in nutritional regimes having differences in protein and carbohydrate compositions. The effect of dietary protein variations on plasticity of absolute size of body and wing dimensions was found to be highly genotype‐dependent as compared to sucrose, in both the sexes and in both the populations. This suggests that variation in proteins in natural environment may induce greater selective pressure on traits and may lead to diversification in morphological structures due to the process of genetic accommodation. We found highly significant genetic variation in plasticity for allometric relationship in Bilaspur population for variations in protein as well as carbohydrate in dietary media. However, constraints in plasticity of allometric slopes for wing dimensions in karyotypic stocks of Varanasi were found in response to both the nutritional variations. The analysis of reaction norms also suggested that there is involvement of alpha inversion present in 2L chromosome of Varanasi population, in adapting to different nutritional environmental conditions due to changes in static allometry of different wing dimensions. Overall, this study reveals that the nutritional ecology and evolutionary allometry govern the morphological divergence of traits size and shape in a genotypic‐dependent manner, thereby resulting in morphological evolutions. [ABSTRACT FROM AUTHOR]

International shipping currently accounts for about 3% of total global greenhouse gas (GHG) emissions, but would continue to rise as transport capacity expands. If the shipping industry aims at delivering its proportionate contribution to curbing global warming under the Paris agreement, the sector has to, inevitably, promote energy conservation and emission reduction. A rapidly growing oceangoing fleet size and correspondingly rising GHG emissions on a global scale raise an interesting research question: could a certain relationship between the two be characterized as a function so that further emissions can be forecast based on the model? The paper adopts an allometric approach based on biological scaling laws to explore the potential relationship between the fleet size and corresponding GHG emissions from shipping. The results show that both the slowdown of the navigation speed and the current implementation of the Energy Efficiency Design Index (EEDI) and Energy Efficiency Operation Index (EEOI) are effective on the whole. By employing the model, the development trends of GHG emissions from shipping in the future can be better understood. Through model applications and result analysis, numerical results validate the effectiveness of this method. The paper not only studies the development of GHG emissions from shipping in the past, but aslo evaluates its specific emission quantities in the future which is in line with the GHG emission reduction targets proposed by IMO on the 72nd IMO meeting, which will be helpful for policy decisions on the quota of GHG emissions to the International Maritime Organization (IMO) and port administrators. • Governance of GHG emissions from shipping is very important. • The relationship between fleet size and GHG emissions is explored. • The effects of different existing GHG emission reduction measures are analyzed. • Future tasks and pressures of GHG emission reduction are assessed. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT Biomass is a fundamental measure for understanding the structure and functioning (e.g. fluxes of energy and nutrients in the food chain) of aquatic ecosystems. We aim to provide predictive models to estimate the biomass of Triplectides egleri Sattler, 1963, in a stream in Central Amazonia, based on body and case dimensions. We used body length, head-capsule width, interocular distance and case length and width to derive biomass estimations. Linear, exponential and power regression models were used to assess the relationship between biomass and body or case dimensions. All regression models used in the biomass estimation of T. egleri were significant. The best fit between biomass and body or case dimensions was obtained using the power model, followed by the exponential and linear models. Body length provided the best estimate of biomass. However, the dimensions of sclerotized structures (interocular distance and head-capsule width) also provided good biomass predictions, and may be useful in estimating biomass of preserved and/or damaged material. Case width was the dimension of the case that provided the best estimate of biomass. Despite the low relation, case width may be useful in studies that require low stress on individuals.

Crop residue is recognized as a potential feedstock for biofuels and a sustainable substitute for fossil energy sources. Expanding the acreage of biofuel crops, it is important to establish a crop residue retention regime to conserve soil fertility and prevent soil erosion. This paper presents simple linear and power equations between stubble biomass ratio (SBR, i. e. percentage of stubble biomass to whole plant biomass) and stubble height ratio (SHR, i. e. percentage of stubble height to maximum plant height) for a wide range of field crops of rice, wheat, oat, corn, sorghum, sunflower, canola, soybean and cotton, using data collected from 15 sites in production fields in 11 provinces across China from 2009 to 2012. Simple linear regressions for the crops were associated with highly significant coefficients of determination (R²) for all crops. Validation with independent datasets also showed high R² values, indicating model goodness-of-fit. Mean relative error (MRE) and root mean square error (RMSE) values showed good fit for the two allometric relationships for each field crop studied. These results could be used to assess stubble mass for sustainable residue removal in bio-based energy systems. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Key message : This work demonstrates that the Olive tree, which is managed and pruned as a fruit tree, can be treated as a forest tree using allometric equations, to estimate both biomass production and volumes. Abstract: The Olive tree ( Olea europaea L.) is an evergreen tree that can grow and accumulate a relatively high amount of dry matter, even in dry environmental conditions common in the Mediterranean basin and typical of traditional rain-fed agriculture. The objective of this research was to develop a tool to predict woody biomass and tree component volume for the olive tree, to be used for different agricultural and environmental purposes. The study was carried out in six olive groves across three locations in Italy, collecting data on the 'Leccino' cultivar, which is spread worldwide. Models for volume and biomass were developed for the whole tree and its different components. Basal diameter and a diameter of 80 cm of the trunk height were explored as independent variables for modeling. The results of this study demonstrate a high correlation between the two selected variables and total biomass, above and below-ground biomass and tree component volumes. The same variables show high correlation with total leaf area, but no correlation with the root/shoot ratio, and Leaf Area Index. [ABSTRACT FROM AUTHOR]

Abstract The diversity and community composition of ground arthropods is routinely analyzed by pitfall trap sampling, which is a cost‐ and time‐effective method to gather large numbers of replicates but also known to generate data that are biased by species‐specific differences in locomotory activity. Previous studies have looked at factors that influence the sampling bias. These studies, however, were limited to one or few species and did rarely quantify how the species‐specific sampling bias shapes community‐level diversity metrics. In this study, we systematically quantify the species‐specific and community‐level sampling bias with an allometric individual‐based model that simulates movement and pitfall sampling of 10 generic ground arthropod species differing in body mass. We perform multiple simulation experiments covering different scenarios of pitfall trap number, spatial trap arrangement, temperature, and population density. We show that the sampling bias decreased strongly with increasing body mass, temperature, and pitfall trap number, while population density had no effect and trap arrangement only had little effect. The average movement speed of a species in the field integrates body mass and temperature effects and could be used to derive reliable estimates of absolute species abundance. We demonstrate how unbiased relative species abundance can be derived using correction factors that need only information on species body mass. We find that community‐level diversity metrics are sensitive to the particular community structure, namely the relation between body mass and relative abundance across species. Generally, pitfall trap sampling flattens the rank‐abundance distribution and leads to overestimations of ground arthropod Shannon diversity. We conclude that the correction of the species‐specific pitfall trap sampling bias is necessary for the reliability of conclusions drawn from ground arthropod field studies. We propose bias correction is a manageable task using either body mass to derive unbiased relative abundance or the average speed to derive reliable estimates of absolute abundance from pitfall trap sampling.

Aquatic invertebrate biomass estimations are often important in ecological and biological studies. Biomass may be determined by regression models between body and case dimensions and dry mass. Using linear, exponential and power regressions we analyzed the relationship between body and case dimensions and the biomass of Phylloicus elektoros Prather, 2003. Furthermore, we used cross-validation to evaluate the predictions of our models and of the models developed for Phylloicus sp. from southeastern Brazil. We measured four body dimensions (head capsule width, interocular distance, body and pronotum length) of 152 larvae and two case dimensions (width and length) of 45 cases. Case width provided better fit with biomass than case length in all model classes. Body length provided the best biomass prediction. Biomass predictions using models proposed in the literature were 75% lower than the observed values. The power model provided the best fit between body and case dimensions with biomass. However, exponential models also provided good biomass estimates. We observed a close fit between body and case dimensions and biomass, but the predictive power of the models was low (~40%). The predictive power of models proposed in the literature was much worse than those built from local data and thus we do not recommend their use to predict the biomass of organisms from different regions.

In forest ecosystem studies, tree stem structure variables (SSVs) proved to be an essential kind of parameters, and now simultaneously deriving SSVs of as many kinds as possible at large scales is preferred for enhancing the frontier studies on marcoecosystem ecology and global carbon cycle. For this newly emerging task, satellite imagery such as WorldView-2 panchromatic images (WPIs) is used as a potential solution for co-prediction of tree-level multifarious SSVs, with static terrestrial laser scanning (TLS) assumed as a ‘bridge’. The specific operation is to pursue the allometric relationships between TLS-derived SSVs and WPI-derived feature parameters, and regression analyses with one or multiple explanatory variables are applied to deduce the prediction models (termed as Model1s and Model2s). In the case ofPicea abies,Pinus sylvestris,Populus tremulandQuercus roburin a boreal forest, tests showed that Model1s and Model2s for different tree species can be derived (e.g. the maximumR2 = 0.574 forQ. robur). Overall, this study basically validated the algorithm proposed for co-prediction of multifarious SSVs, and the contribution is equivalent to developing a viable solution for SSV-estimation upscaling, which is useful for large-scale investigations of forest understory, macroecosystem ecology, global vegetation dynamics and global carbon cycle. [ABSTRACT FROM AUTHOR]

The diversity and community composition of ground arthropods is routinely analyzed by pitfall trap sampling, which is a cost‐ and time‐effective method to gather large numbers of replicates but also known to generate data that are biased by species‐specific differences in locomotory activity. Previous studies have looked at factors that influence the sampling bias. These studies, however, were limited to one or few species and did rarely quantify how the species‐specific sampling bias shapes community‐level diversity metrics. In this study, we systematically quantify the species‐specific and community‐level sampling bias with an allometric individual‐based model that simulates movement and pitfall sampling of 10 generic ground arthropod species differing in body mass. We perform multiple simulation experiments covering different scenarios of pitfall trap number, spatial trap arrangement, temperature, and population density. We show that the sampling bias decreased strongly with increasing body mass, temperature, and pitfall trap number, while population density had no effect and trap arrangement only had little effect. The average movement speed of a species in the field integrates body mass and temperature effects and could be used to derive reliable estimates of absolute species abundance. We demonstrate how unbiased relative species abundance can be derived using correction factors that need only information on species body mass. We find that community‐level diversity metrics are sensitive to the particular community structure, namely the relation between body mass and relative abundance across species. Generally, pitfall trap sampling flattens the rank‐abundance distribution and leads to overestimations of ground arthropod Shannon diversity. We conclude that the correction of the species‐specific pitfall trap sampling bias is necessary for the reliability of conclusions drawn from ground arthropod field studies. We propose bias correction is a manageable task using either body mass to derive unbiased relative abundance or the average speed to derive reliable estimates of absolute abundance from pitfall trap sampling. [ABSTRACT FROM AUTHOR]

The cortex (i.e., absorptive tissue) and stele (transportive vascular tissue) are fundamental to the function of plant roots. Unraveling how these anatomical structures are assembled in absorptive roots is essential for our understanding of plant ecology, physiology, and plant responses to global environmental changes. In this review, we first compile a large data set on anatomical traits in absorptive roots, including cortex thickness and stele radius, across 698 observations and 512 species. Using this data set, we reveal a common root allometry in absorptive root structures, i.e., cortex thickness increases much faster than stele radius with increasing root diameter (hereafter, root allometry). Root allometry is further validated within and across plant growth forms (woody, grass, and liana species), mycorrhiza types (arbuscular mycorrhiza, ectomycorrhiza, and orchid mycorrhizas), phylogenetic gradients (from ferns to Orchidaceae), and environmental change scenarios (e.g., elevation of atmospheric CO 2 concentration and nitrogen fertilization). These findings indicate that root allometry is common in plants. Importantly, root allometry varies greatly across species. We then summarize recent research on the mechanisms of root allometry and potential issues regarding these mechanisms. We further discuss ecological and evolutionary implications of root allometry. Finally, we propose several important research directions that should be pursued regarding root allometry., Competing Interests: We declare that we have no conflict interest., (© 2023 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.)

Criteria for N diagnostics have been developed for a range of agricultural crops. The Nitrogen Nutrition Index (NNI) is a widely used indicator of N status. The NNI represents the relationship between above-ground N concentration and an estimated critical N concentration (N c ), which is the minimum N concentration allowing maximum crop growth rate at a given above-ground biomass (W). Although the NNI has been determined for a wide range of agricultural crops, the conceptual basis that explains N dilution patterns have not yet been validated in crops with large storage organs such as fodder beet ( Beta vulgaris L. ssp. vulgaris ). In this study, we assessed the validity of the N c and the NNI for fodder beet based on two field datasets with a wide range of N treatments (0–200 kg ha −1 ) and water supply (rain-fed and irrigated) conditions in New Zealand. The N c and NNI concepts were shown to be valid for crops with large storage organs. A pattern of N dilution, similar to other agricultural crops, was represented by N c = 4.9 W −0.52 (R 2 = 0.97) for biomass (W) ranging from 1.1 to 28 t W ha −1 . The dynamics of N dilution was explained by a simultaneous relative increase in the biomass of storage roots, which have the lowest N concentrations, and a decline in N concentration of all organs (leaves, petioles and storage roots) as W increased. The NNI values calculated from the N c curve ranged from 0.6 to 1.74 with relative biomass declining at NNI < 1. Water stressed crops showed luxury N uptake (NNI up to 1.74) highlighting need for careful interpretation of NNI values depending on growth conditions. These results can be used to manage N supply in fodder beet, and to support analysis and modelling of physiological responses to N supply in crops with large storage organs. [ABSTRACT FROM AUTHOR]

Domestication of animals has resulted in phenotypic changes by means of natural and human-directed selection. Body composition is important for farm animals because it reflects the status of energy reserves. Thus, there is the possibility that farm animals as providers of food have been more affected by human-directed selection for body composition than laboratory animals. In this study, an analysis was conducted to determine what similarities and differences in body composition occur between farm and laboratory animals using literature data obtained from seven comparative slaughter studies (n = 136 observations). Farm animals from four species (cattle, goats, pigs and sheep) were all castrated males, whereas laboratory animals from three species (dogs, mice and rats) comprised males and/or females. All animals were fed ad libitum. The allometric equation, Y = aXb, was used to determine the influence of species on the accretion rates of chemical components (Y, kg) relative to the growth of the empty body, fat-free empty body or protein weights (X, kg). There were differences between farm and laboratory animals in terms of the allometric growth coefficients for chemical components relative to the empty BW and fat-free empty BW (P < 0.01); farm animals had more rapid accretion rates of fat (P < 0.01) but laboratory animals had more rapid accretion rates of protein, water and ash (P < 0.01). In contrast, there was no difference in terms of the allometric growth coefficients for protein and water within farm animals (P > 0.2). The allometric growth coefficients for ash weight relative to protein weight for six species except sheep were not different from a value of 1 (P > 0.1), whereas that of sheep was smaller than 1 (P < 0.01). When compared at the same fat content of the empty body, the rate of change in water content (%) per unit change in fat content (%) was not different (P > 0.05) across farm animal species and similar ash-to-protein ratios were obtained except for dogs. The fraction of empty body energy gain retained as fat increased in a curvilinear manner, and there was little variation among farm animals at the same fat content of the empty body. These findings may provide the opportunity to develop a general model to predict empty body composition across farm animal species. In contrast, there were considerable differences of chemical body composition between farm and laboratory animals.