Okoume

Aucoumea klaineana is endemic to the tropical forests of Gabon and immediately adjacent areas.

• Almost entirely restricted to Gabon, with limited extensions into Equatorial Guinea, Congo, and Cameroon near the Gabonese border
• Found in lowland evergreen and semi-deciduous forests from sea level to approximately 600 m
• Prefers well-drained, sandy to clayey soils in humid tropical conditions
• Annual rainfall in its range is 1,500-3,000 mm
• A gregarious species that can form nearly pure stands, sometimes dominating large areas of forest
• First described by the French botanist Jean Baptiste Louis Pierre in 1896
• Named in honor of the French colonial administrator Klaine
• Accounts for approximately 70-80% of Gabon's total timber production
• Populations have declined due to heavy logging but remain relatively extensive

A large, buttressed, evergreen rainforest tree.

Trunk and Crown:
• Height: 40-50 m with a tall, cylindrical, slightly crooked bole
• Trunk diameter: 80-160 cm, with prominent, thick buttresses extending 1-3 m up the trunk
• Bark: grayish to reddish-brown, thick, rough, exuding a resinous sap when cut
• Crown: large, rounded to irregular, with massive spreading branches
• Young branches are densely scaly and resinous

Leaves:
• Pinnately compound, alternate, 20-40 cm long with 6-10 pairs of leaflets
• Leaflets are elliptic to oblong, 8-15 cm long and 3-5 cm wide
• Dark glossy green above, paler and often scaly beneath
• Petioles 5-10 cm long, slightly winged

Flowers:
• Small, greenish-white to cream-colored, 3-4 mm long
• Arranged in large, spreading terminal panicles 15-30 cm long
• Flowers are unisexual (dioecious), with male and female flowers on separate trees
• Pollinated by insects

Fruit:
• A small, ovoid to ellipsoidal capsule 2-3 cm long
• Brown to reddish-brown when mature, splitting into 5 valves
• Contains a single seed with a small wing
• Seeds are dispersed by wind and gravity

Okoume is a gregarious species that plays a unique ecological role in Gabonese forests.

• Often forms nearly pure stands, a rarity among tropical rainforest trees
• A canopy to emergent species that can dominate large areas of forest
• Dioecious reproductive system requires both male and female trees for seed production
• Resinous bark and wood may provide defense against herbivorous insects and pathogens
• Flowers provide nectar for diverse insect communities
• Seeds are relatively heavy and dispersed mainly near the parent tree
• Supports epiphyte communities in its large crown
• Plays a significant role in watershed protection in the Gabonese coastal plain
• Can regenerate in logged areas but requires canopy gaps for seedling establishment

Okoume is cultivated primarily in plantation settings within tropical Africa.

• Requires hot, humid tropical conditions with annual rainfall exceeding 1,500 mm
• Prefers well-drained, sandy to clayey forest soils
• Propagation is by seed; seeds should be collected from mature capsules and sown promptly
• Germination occurs within 15-30 days under warm, moist conditions
• Seedlings are shade-tolerant initially but require increasing light for rapid growth
• Growth is relatively fast, reaching 8-12 m in 10 years under optimal conditions
• Planting densities of 200-400 trees per hectare for timber plantations
• Rotation cycles of 25-40 years for commercial timber
• Requires thinning at 8-12 years to promote straight bole development
• Responds well to enrichment planting in logged-over forests