A 3D approach to model the taper of irregular tree stems: making plots biomass estimates comparable in tropical forests

Autor: Gauthier Ligot, Sébastien Bauwens, Pierre Ploton, Philippe Lejeune, Jean Joël Loumeto, Adeline Fayolle, Sylvie Gourlet-Fleury
Přispěvatelé: TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, Université de Liège - Gembloux-Université de Liège - Gembloux, Université de Liège - Gembloux, Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université Marien Ngouabi, Forêts et Sociétés (UPR Forêts et Sociétés), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Département Environnements et Sociétés (Cirad-ES)
Rok vydání: 2021
Předmět:
0106 biological sciences
010504 meteorology & atmospheric sciences
Point of measurement of stem diameter
forêt tropicale
Forests
[SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics
Phylogenetics and taxonomy
01 natural sciences
Trees
Allométrie
biomasse aérienne des arbres
buttresses
K01 - Foresterie - Considérations générales
Biomass changes
parcelle
Range (statistics)
Biomass
Tronc
Biomass (ecology)
Close-range terrestrial photogrammetry
Ecology
U10 - Informatique
mathématiques et statistiques
Stem profile
Carbon sink
[SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics
Taper
Carbon Sequestration
Pantropical
010603 evolutionary biology
[SDV.EE.ECO]Life Sciences [q-bio]/Ecology
environment/Ecosystems
Stock (geology)
0105 earth and related environmental sciences
Tropical Climate
Allometric aboveground biomass model
Forest inventory
Structure from motion
Tropics
15. Life on land
Data set
Modélisation
Environmental science
Dendrométrie
Physical geography
[SDE.BE]Environmental Sciences/Biodiversity and Ecology
Zdroj: Ecological Applications
Ecological Applications, Ecological Society of America, 2021, 31 (8), ⟨10.1002/eap.2451⟩
ISSN: 1939-5582
1051-0761
DOI: 10.1002/eap.2451
Popis: International audience; In tropical forests, the high proportion of trees showing irregularities at the stem base complicates forest monitoring. For example, in the presence of buttresses, the height of the point of measurement (HPOM) of the stem diameter (DPOM) is raised from 1.3 m, the standard breast height, up to a regular part of the stem. While DPOM is the most important predictor for tree aboveground biomass (AGB) estimates, the lack of harmonized HPOM for irregular trees in forest inventory increases the uncertainty in plot-level AGB stock and stock change estimates. In this study, we gathered an original non-destructive three-dimensional (3D) data set collected with terrestrial laser scanning and close range terrestrial photogrammetry tools in three sites in central Africa. For the 228 irregularly shaped stems sampled, we developed a set of taper models to harmonize HPOM by predicting the equivalent diameter at breast height (DBH′) from a DPOM measured at any height. We analyzed the effect of using DBH′ on tree-level and plot-level AGB estimates. To do so, we used destructive AGB data for 140 trees and forest inventory data from eight 1-ha plots in the Republic of Congo. Our results showed that our best simple taper model predicts DBH′ with a relative mean absolute error of 3.7% (R2 = 0.98) over a wide DPOM range of 17–249 cm. Based on destructive AGB data, we found that the AGB allometric model calibrated with harmonized HPOM data was more accurate than the conventional local and pantropical models. At the plot level, the comparison of AGB stock estimates with and without HPOM harmonization showed an increasing divergence with the increasing share of irregular stems (up to −15%). The harmonization procedure developed in this study could be implemented as a standard practice for AGB monitoring in tropical forests as no additional forest inventory measurements is required. This would probably lead to important revisions of the AGB stock estimates in regions having a large number of irregular tree stems and increase their carbon sink estimates. The growing use of three-dimensional (3D) data offers new opportunities to extend our approach and further develop general taper models in other tropical regions.
Databáze: OpenAIRE
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