Trees spatial pattern, diversity and distribution in sub humid mountains ecosystems in south-west Togo

Abstract

West African Guinean forests are among the most diverse and threatened ecosystems in the world. The study aims to provide new insights about tree species patterns, abundance, and diversity for better management in Togo. Species diversity and density of trees were assessed in 170 plots randomly selected in the study area. Each tree with DBH >10 cm was identified and measured. Stem density, basal area, and diversity indices were calculated. In total, 243 species belonging to 170 genera and 44 families were identified in the study area. Five floristic groups were recognized. They are characterized respectively by Lophira lanceolata, Pterocarpus erinaceus and Daniellia oliveri association in Group 1; Theobroma cacao, Elaeis guineensis and Morinda lucida association in Group 2; Elaeis guineensis, Persea Americana and Albizia zygia association in Group 3; Cola gigantea, Senna siamea and Erythrophleum suaveolens association in Group 4 and Pycnanthus angolensis, Ceiba pentandra and Pseudospondias microcarpa association in Group 5. The Fabaceae, Moraceae and Malvaceae are the most represented families in the study area. The highest tree species diversity was observed in Group 4 (2.05 ± 0.61) and the lowest diversity in Group 2 (1.19 ± 0.64). Mean tree density ranges from 408.96± 202.17 (Group 1) to 273.90 ± 193.19 (Group 4). The highest tree basal area (27.99 ± 25.58 m 2 /ha) is obtained in Group 3 and the lowest (15.84 ± 13.44 m 2 /ha) is in Group 4. The presence of pioneer species in the study areas proves that the habitat has undergone serious anthropogenic disturbance events, which contribute to species loss.