Forest dynamic and trees regeneration in the logging gaps in Gabon

Nestor Laurier Engone Obiang; Raymonde Mboma; Martial-T Mba Nzuè; Raoul Niangadouma; Joanick Menvi Nzomo; Aaron-Matlands Magama-Mucketou; Éric Chézeaux

doi:10.15468/kbg449

Forest dynamic and trees regeneration in the logging gaps in Gabon

Citation

Engone Obiang N L, Mboma R, Mba Nzuè M, Niangadouma R, Menvi Nzomo J, Magama-Mucketou A, Chézeaux É (2023). Forest dynamic and trees regeneration in the logging gaps in Gabon. Version 1.6. Herbier National du Gabon. Sampling event dataset https://doi.org/10.15468/kbg449 accessed via GBIF.org on 2025-05-15.

Description

This is the extracted data of the post-logging regeneration of commercial species in forest concessions under sustainable management (FSCM) in Gabon project funded by Sud Expert Plantes Développement Durable program (SEP2D) under the AAP2-81 project code. The main aim of this project was to support logging companies involved in the certification process to monitor forest regeneration relating to Forest Stewardship for the Congo Basin Region (FSC) which recommends the forest manager to set up mechanisms to monitor natural regeneration in the areas impacted by logging according to 6.3.2 indicator. Study was carried in the certified FSCM of the Rougier-Gabon company by the Institut de Recherche en Ecologie Tropicale (IRET). To monitor forest dynamic and trees regeneration of the forest areas impacted by logging, data from 652 plots of 30 m2 established on the skid trails and the 141 others from felling gaps whose sizes vary between 3,8 to 20 m2 was exploited. Skid trails are used for log extraction. Every tree ≥ 1 cm in diameter at breast height (dbh; 1.3 m above ground level) was measured.

Sampling Description

Study Extent

Study was carried in two FSCM of the Rougier-Gabon company, that of Haut-Abanga (288,626 ha), in the northwest and the Moyabi one, in the southeast of Gabon (71,716 ha). Rougier-Gabon was also a project partner.

Sampling

To collect data, 652 plots was established on the skid trails and the 141 others in the felling gaps of the two forest concessions, either a total of 793 plots.

Quality Control

GBIF species matching and BRAHMS database was used for data quality control. After species identification in the field their confirmation was done by the Herbier national du Gabon botanists.

Method steps

In the two FSCM of the Rougier-Gabon company, data come from 652 plots of 30 m2 in the skid trails and the 141 others whose size varies from 3.38 to 20 m2 from felling gaps. The skid trails and the felling gaps are themselves located in the annual areas cutting from 0 to 26 years old. The plots, 100 m apart from center to center, was placed along the skid trails and numbered from 1 to n; 1 being the first plot, adjacent to the road or park and n le last one, inside the forest. The plots of the felling gaps of the same area (20 m2) were successively placed in the axis which connects the stump to the crown. They were also numbered from 1 (first plot after the stump) to n, last plot of variable size X. In the two cases, every tree ≥ 1 cm in diameter at breast height (dbh; 1.3 m above ground level) was measured.

Taxonomic Coverages

These data that come from 793 plots contain 6251 trees including 276 species, 184 genera and 56 families. The both logging gaps are characterized by the similar floristic compositions where the light-demanding taxa as Macaranga, Alcornea, Xylopia, Discoglypremna, Dichostemma and Harungana are more abundants.

Apocynaceae
rank: family
Aptandraceae
rank: family
Asteraceae
rank: family
Burseraceae
rank: family
Cannabaceae
rank: family
Cardiopteridaceae
rank: family
Centroplacaceae
rank: family
Chrysobalanaceae
rank: family
Clusiaceae
rank: family
Connaraceae
rank: family
Coulaceae
rank: family
Dipterocarpaceae
rank: family
Ebenaceae
rank: family
Erythroxylaceae
rank: family
Euphorbiaceae
rank: family
Fabaceae
rank: family
Gelsemiaceae
rank: family
Gentianaceae
rank: family
Huaceae
rank: family
Hypericaceae
rank: family
Irvingiaceae
rank: family
Ixonanthaceae
rank: family
Lamiaceae
rank: family
Lauraceae
rank: family
Lecythidaceae
rank: family
Malvaceae
rank: family
Melastomataceae
rank: family
Meliaceae
rank: family
Moraceae
rank: family
Myristicaceae
rank: family
Myrtaceae
rank: family
Ochnaceae
rank: family
Olacaceae
rank: family
Pandaceae
rank: family
Passifloraceae
rank: family
Peraceae
rank: family
Phyllanthaceae
rank: family
Polygalaceae
rank: family
Putranjivaceae
rank: family
Rhamnaceae
rank: family
Rhizophoraceae
rank: family
Rubiaceae
rank: family
Rutaceae
rank: family
Salicaceae
rank: family
Sapindaceae
rank: family
Sapotaceae
rank: family
Simaroubaceae
rank: family
Stemonuraceae
rank: family
Strombosiaceae
rank: family
Thomandersiaceae
rank: family
Urticaceae
rank: family
Violaceae
rank: family
Vochysiaceae
rank: family

Geographic Coverages

Study was carried out in the certified forest concessions of Rougier-Gabon, especially those of Haut-Abanga, in the northwest (293,833 ha) and Moyabi (188,989 ha), in the southeast of Gabon.

Bibliographic Citations

Brunck, F., Grison, F., & Maitre, H. F. (1990). Okoume (Aucoumea klaineana): a monograph. Okoume (Aucoumea klaineana): a monograph. -
Engone Obiang N.L., Ngomanda A., Hymas O., Chézeaux É. & Picard N. 2014. Diagnosing the demographic balance of two light-demanding tree species populations in central Africa from their diameter distribution. Forest Ecology and Management 313: 55–62. -
Engone Obiang Nestor, Mba Nzuè Martial-T et Niangadouma Raoul – 2019 : Régénération post exploitation des essences commerciales dans les concessions forestières sous aménagement durable au Gabon. Rapport final du projet Sud Expert Plante AAP2-81 -
Gravel, D., Canham, C. D., Beaudet, M., & Messier, C. (2010). Shade tolerance, canopy gaps and mechanisms of coexistence of forest trees. Oikos, 119(3), 475-484. -
Poorter, L., & Rose, S. A. (2005). Light-dependent changes in the relationship between seed mass and seedling traits: a meta-analysis for rain forest tree species. Oecologia, 142(3), 378-387. Rougier Gabon, Plan d’aménagement des CAD du Haut Abanga et de Moyabi -

Contacts

Nestor Laurier Engone Obiang
originator
position: Researcher
IRET/CENAREST
Arboretum de Sibang BP 1156
Libreville
Estuaire
GA
email: engoneobiangnestor@gmail.com

Raymonde Mboma
originator
position: Researcher
IRET/CENAREST
243 Avenue Félix Houphouët Boigny BP 13354
Libreville
Estuaire
GA
email: mboma_raymonde@yahoo.fr

Martial-T Mba Nzuè
originator
position: Technicien superieur
IPHAMETRA

Raoul Niangadouma
originator
position: Technicien
IPHAMETRA

Joanick Menvi Nzomo
originator
position: Technicien
IPHAMETRA

Aaron-Matlands Magama-Mucketou
originator
position: Forestier
Rougier Gabon
Libreville

Éric Chézeaux
originator
position: Forestier
Rougier Gabon
Libreville

Nestor Laurier Engone Obiang
metadata author
position: Researcher
IPHAMETRA/CENAREST
Arboretum de Sibang BP 1156
Libreville
Estuaire
GA
Telephone: +241 62461946
email: engoneobiangnestor@gmail.com

Nestor ENGONE OBIANG
publisher
position: Directeur adjoint
IPHAMETRA
Arboratum de Sibang BP 1156
Libreville
Estuaire
GA
email: engoneobiangnestor@gmail.com

Nestor Laurier Engone Obiang
administrative point of contact
position: Researcher
IRET/CENAREST
Arboretum de Sibang BP 1156
Libreville
Estuaire
GA
email: engoneobiangnestor@gmail.com

Raymonde Mboma
administrative point of contact
position: Researcher
IRET/CENAREST
243 Avenue Félix Houphouët Boigny BP 13354
Libreville
Estuaire
GA
email: mboma_raymonde@yahoo.fr

Pulchérie Bissiengou
administrative point of contact
position: Researcher
IRET/CENAREST
Arboretum de Sibang BP 1156
Libreville
Estuaire
GA
email: bissiengou_p@yahoo.fr