Floristic inventory and diversity assessment of a lowland African Montane Rainforest at Korup, Cameroon and implications for conservation

• Published in: African journal of ecology 2010-09, Vol.48 (3), p.759-768
• Main Authors: Mbue, Innocent Ndoh, Ge, Jiwen, Kanyamanda, Kasereka, Nowel Njamnsi, Yinkfu, Samake, Mamadou
• Format: Article
• Language: English
• Subjects: Biodiversity; canonical correspondence analysis; Canopies; Conservation biology; diversity profiles; Ebenaceae; Flowers & plants; Korup National Park; modified-Whittaker plots; Rainforests; rank-abundance curves; Sampling; species-response curves
• ISSN: 0141-6707; 1365-2028
• DOI: 10.1111/j.1365-2028.2009.01176.x

Twenty modified-Whittaker plots were stratified at different sampling locations from February to May of 2008 in the central zone of Korup National Park, Cameroon. Our interest was to assess floristic diversity and investigate their relationship with environmental variables. Diversity profiles and rank abundance-curves were used for diversity analysis while canonical correspondence analysis and species-response curves were used to investigate the relationships between the response and explanatory variables. Of the 66 families identified, the Rubiaceae (999 species) were the most abundant. The Sterculiaceae (basal area = 10.482 m² ha⁻¹) were the dominant family, while the co-dominant families included the Ebenaceae (basal area = 9.092 m² ha⁻¹) and the Euphorbiaceae (basal area = 8.168 m² ha⁻¹). Soil variables explained 54.3% of total variation in family distribution. Canonical axes were related to different environmental gradients: axis1 was related to increasing canopy cover (r = 0.6951); axis 2, increasing Magnesium (r = 0.8465) and effective cation exchange capacity (r = 0.5899); axis 3, increasing effective cation exchange capacity (r = 0.5536); while axis 4, increasing Phosphorus concentration (r = 0.5232). Our results demonstrate the advantage which diversity profiles have over single or combination of indices, and the importance of using a combination of methodologies in diversity analysis.