Articles containing the keyword 'allometric equations'

Currently, tools to predict the aboveground and belowground biomass (AGB and BGB) of woody species in Guinean savannas (and the data to calibrate them) are still lacking. Multispecies allometric equations calibrated from direct measurements can provide accurate estimates of plant biomass in local ecosystems and can be used to extrapolate local estimates of carbon stocks to the biome scale. We developed multispecies models to estimate AGB and BGB of trees and multi-stemmed shrubs in a Guinean savanna of Côte d’Ivoire. The five dominant species of the area were included in the study. We sampled a total of 100 trees and 90 shrubs destructively by harvesting their biometric data (basal stem diameter D_b, total stem height H, stump area S_S, as well as total number of stems n for shrubs), and then measured their dry AGB and BGB. We fitted log-log linear models to predict AGB and BGB from the biometric measurements. The most relevant model for predicting AGB in trees was fitted as follows: AGB = 0.0471 (ρD_b²H)^0.915 (with AGB in kg and ρD_b²H in g cm^–1 m). This model had a bias of 19%, while a reference model for comparison (fitted from tree measurements in a similar savanna ecosystem, Ifo et al. 2018) overestimated the AGB of trees of our test savannas by 132%. The BGB of trees was also better predicted from ρDb2H as follows: BGB = 0.0125 (ρD_b²H)^0.6899 (BGB in kg and ρD_b²H in g cm^–1 m), with 6% bias, while the reference model had about 3% bias. In shrubs, AGB and BGB were better predicted from ρD_b²H together with the total number of stems (n). The best fitted allometric equation for predicting AGB in shrubs was as follows: AGB = 0.0191 (ρD_b²H)^0.6227 n^0.9271. This model had about 1.5% bias, while the reference model overestimated the AGB of shrubs of Lamto savannas by about 79%. The equation for predicting BGB of shrubs is: BGB = 0.0228 (ρD_b²H)^0.7205 n^0.992 that overestimated the BGB of the shrubs of Lamto savannas with about 3% bias, while the reference model underestimated the BGB by about 14%. The reference model misses an important feature of fire-prone savannas, namely the strong imbalance of the BGB/AGB ratio between trees and multi-stemmed shrubs, which our models predict. The allometric equations we developed here are therefore relevant for C stocks inventories in trees and shrubs communities of Guinean savannas.

• Kouamé, UFR Sciences de la Nature, UFR-SN/ Station d’Ecologie de Lamto (CRE), Pôle de recherche Environnement et Développement Durable, Université NANGUI ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire); Institute of Ecology and Environmental Sciences IEES-Paris (Sorbonne Université, CNRS, Université Paris Diderot, IRD, UPEC, INRA), 4 Place Jussieu, 75005, Paris, France https://orcid.org/0000-0002-0847-2569 E-mail: kouameyag@gmail.com
• Millan, Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa; Global Change Biology Group, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa; Institute of Botany of the Czech Academy of Sciences, v.v.i, Dukelská 135, Třeboň, 379 01, Czech Republic https://orcid.org/0000-0002-0151-6055 E-mail: mathieu.millan@gmail.com
• N'Dri, UFR Sciences de la Nature, UFR-SN/ Station d’Ecologie de Lamto (CRE), Pôle de recherche Environnement et Développement Durable, Université NANGUI ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire https://orcid.org/0000-0002-6333-6279 E-mail: brigitte.aya@gmail.com
• Charles-Dominique, Institute of Ecology and Environmental Sciences IEES-Paris (Sorbonne Université, CNRS, Université Paris Diderot, IRD, UPEC, INRA), 4 Place Jussieu, 75005, Paris, France https://orcid.org/0000-0002-5767-0406 E-mail: tristan.charles-dominique@sorbonne-universite.fr
• Konan, UFR Sciences de la Nature, UFR-SN/ Station d’Ecologie de Lamto (CRE), Pôle de recherche Environnement et Développement Durable, Université NANGUI ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire E-mail: marcelkonan.lamto@gmail.com
• Bakayoko, UFR Sciences de la Nature, UFR-SN/ Station d’Ecologie de Lamto (CRE), Pôle de recherche Environnement et Développement Durable, Université NANGUI ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire E-mail: bakadamaci@yahoo.fr
• Gignoux, Institute of Ecology and Environmental Sciences IEES-Paris (Sorbonne Université, CNRS, Université Paris Diderot, IRD, UPEC, INRA), 4 Place Jussieu, 75005, Paris, France https://orcid.org/0000-0003-3853-9282 E-mail: jacques.gignoux@upmc.fr

The quantification of the contribution of tropical forests to global carbon stocks and climate change mitigation requires availability of data and tools such as allometric equations. This study made available volume and biomass models for eighteen tree species in a semi-deciduous tropical forest in West Africa. Generic models were also developed for the forest ecosystem, and basic wood density determined for the tree species. Non-destructive sampling approach was carried out on five hundred and one sample trees to analyse stem volume and biomass. From the modelling of volume and biomass as functions of diameter at breast height (Dbh) and stem height, logarithmic models had better predictive capabilities. The model validation showed that in absence of data on height, models using Dbh only as variable was an alternative. The comparison of basic wood densities to data published in literature enabled to conclude that the non-destructive sampling was a good approach to determining reliable basic wood density. The comparative analysis of species-specific models in this study with selected generic models for tropical forests indicated low probability to identify effective generic models with good predictive ability for biomass. Given tree species richness of tropical forests, the study demonstrated the hypothesis that species-specific models are preferred to generic models, and concluded that further research should be oriented towards development of specific models to cover the full range of dominant tree species of African forests.

• Goussanou, Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01 BP 526 Cotonou, Benin E-mail: cedricgoussanou@gmail.com
• Guendehou, Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01 BP 526 Cotonou, Benin; Benin Centre for Scientific and Technical Research, 03 BP 1665 Cotonou, Benin E-mail: sguendehou@yahoo.fr
• Assogbadjo, Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01 BP 526 Cotonou, Benin E-mail: assogbadjo@yahoo.fr
• Kaire, Centre Régional AGRHYMET, Département Formation et Recherche, BP 11011 Niamey, Niger E-mail: m.kaire@agrhymet.ne
• Sinsin, Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01 BP 526 Cotonou, Benin E-mail: bsinsin@gmail.com
• Cuni-Sanchez, University of Copenhagen, Center for Macroecology, Evolution and Climate, Nørregade 10, P.O. Box 2177, 1017 Copenhagen K, Denmark E-mail: aidacuni@hotmail.com

• Bijak, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Nowoursynowska 159, 02-776 Warszawa, Poland E-mail: szymon.bijak@wl.sggw.pl
• Zasada, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Nowoursynowska 159, 02-767 Warszawa, Poland E-mail: michal.zasada@wl.sggw.pl
• Bronisz, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: agnieszka.bronisz@wl.sggw.pl
• Bronisz, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: karol.bronisz@wl.sggw.pl
• Czajkowski, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: maciej.czajkowski@wl.sggw.pl
• Ludwisiak, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: lukasz.ludwisiak@wl.sggw.pl
• Tomusiak, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: robert.tomusiak@wl.sggw.pl
• Wojtan, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: rafal.wojtan@wl.sggw.pl

• Grote, TU München, Chair of Forest Yield Science, Am Hochanger 13, D-85354 Freising, Germany E-mail: ruediger.grote@lrz.tu-muenchen.de

Species-specific allometric equations for shrubs and small trees are relatively scarce, thus limiting the precise quantification of aboveground biomass (AGB) in both shrubby vegetation and forests. Fourteen shrub and small tree species in Eastern China were selected to develop species-specific and multispecies allometric biomass equations. Biometric variables, including the diameter of the longest stem (D), height (H), wet basic density (BD), and crown area and shape were measured for each individual plant. We measured the AGB through a non-destructive method, and validated these measurements using the dry mass of the sampled plant components. The AGB was related to biometric variables using regression analysis. The species-specific allometric models, with D and H as predictors (D-H models) accounted for 70% to 99% of the variation in the AGB of shrubs and small trees. A multispecies allometric D-H model accounted for 71% of the variation in the AGB. Although BD, as an additional predictor, improved the fit of most models, the D-H models were adequate for predicting the AGB for shrubs and small trees in subtropical China without BD data.

• Ali, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Tiantong National Forest Ecosystem Observations and Research Station, Ningbo 315114, Zhejiang, China; Department of Environmental Sciences, Abdul Wali Khan University Mardan, 23200, KPK, Pakistan E-mail: arshadforester@gmail.com
• Xu, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Tiantong National Forest Ecosystem Observations and Research Station, Ningbo 315114, Zhejiang, China E-mail: yumsh09@lzu.edu.cn
• Zhao, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Tiantong National Forest Ecosystem Observations and Research Station, Ningbo 315114, Zhejiang, China E-mail: zhaoyantao1991@163.com
• Zhang, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Tiantong National Forest Ecosystem Observations and Research Station, Ningbo 315114, Zhejiang, China E-mail: qingzq@yeah.net
• Zhou, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Tiantong National Forest Ecosystem Observations and Research Station, Ningbo 315114, Zhejiang, China E-mail: 792920738@qq.com
• Yang, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Tiantong National Forest Ecosystem Observations and Research Station, Ningbo 315114, Zhejiang, China E-mail: xjyangxd@sina.com
• Yan, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China; Tiantong National Forest Ecosystem Observations and Research Station, Ningbo 315114, Zhejiang, China E-mail: eryan@des.ecnu.edu.cn