Menaces anthropiques sur milicia exelsa. (welw) c.c berg dans la plaine du Litime (sud-ouest Togo)

Abstract

Milicia excelsa is a spontaneous plant resource that is the subject of commercial products in the plain of Litimé (Prefecture of Wawa) in the south-west of Togo. Due to its commercial value and the quality of its timber, it is over-exploited. This overexploitation causes its rarefaction. The objective of the study is to evaluate the potential of Milicia excelsa and then to determine the forms of human pressure on the species and to identify the main management measures for the species in the locality. Through the transect method, 43 itinerant 20m x 20m (400m²) surveys were carried out. The classes of diameters and heights were made using the metric tape for diameters and visual observation for the heights. Densities and land areas by vegetation and canton were also calculated. To estimate the density of the regeneration, sub-plots of 5 m × 5 m were carried out. Regarding the determination of the main degradation factors of Milicia excelsa and the management strategies put in the place by local populations, two types of questionnaires were administered to farmers and operators. The results of the study identified 84 adult feet of Milicia excelsa. The majority of the trees counted have a diameter between (20-50) cm and a height between (20-25) m. Agroforests are the most represented with a density of 5.5 feet / hectare and 0.002007 m² of basal area. The highest density is found in the Township of Tomégbé (5.4 feet / hectare), while the largest basal area is in the Kpete-Bena Township (0.0023 m² / hectare). The greatest density of regeneration is found in forest recruits with 3.2 Feet / hectare. The different forms of human pressure on Milicia excelsahave shown that culling is the main factor (75%) followed by vegetation fires (20%) and crop clearing (5%). Sustainable management measures are limited. The boil down to the protection and reforestation of seedling and implementation of the regulations goveming the exploitation of timbers. The various uses of iroko reflect the urgency and the need to reinforce management plans for the areas colonized by the species with a view to its safeguarding in the Litimé.

Keywords:Milicia excelsa, Litimé, Anthropogenic threats, Togo

Sigles et acronymes

FAO : Fond des Nations Unis pour l'Alimentation et l'Agriculture

ATIBT : Association Technique Internationale des Bois Tropicaux

ODEF : Office de Développement et l'Exploitation des Forêts

APAF : Association pour la Promotion des Arbres Fertiliaires.

ICAT : Institut de Conseil et d'Appui Technique.

ITRA : Institut Togolaise de Recherche Agronomique

SRCC : Société pour la Rénovation de la Caféière et de la Cacaoyère

ONG : Organisation Non Gouvernementale

LaRBE : Laboratoire de Recherches Biogéographiques et d'Etudes Environnementales

UICN : Union Internationale pour la Conservation de la Nature

IAWA: The International Association of Wood Anatomists.

GPS : Global Positioning System

INSEED : Institut National de la Statistique et de Etudes Economiques et Démographiques

Sommaire

Introduction 1

Chapitre 1 : CADRE CONCEPTUEL ET APPROCHE METHODOLOGIQUE 11

1.1 Problématique 11

1.2 Hypothèses 14

1.3 Objectifs de recherche 14

Chapitre 2. MATERIEL ET METHODE 21

2.1 Matériel 21

2.2 Méthodes 28

Chapitre 3 : LE MILIEU PHYSIQUE ET HUMAIN 34

3.1 Milieu Physique 34

3.2 Milieu humain 42

Chapitre 4 RESULTATS 49

Chapitre 5. DISCUSSION 78

Conclusion et suggestions 82

Références bibliographiques 85

ANNEXES 89