Flora of Isoberlinia spp. woodlands in the sudanian zone of Togo

This paper contributes to a better knowledge of Isoberlinia spp. woodlands in the Sudanian zone of Togo. 508 woody and herbaceous species belonging to 314 genera and 78 families (table 1) were recorded in 225 plots of 400 m(2), including three new citations for woodland flora: Thunbergia atacoriensis, Erythroxylum emarginatum, Chaetachme madagascariensis. 13 families account for 62.4 % of species, and are represented by at least 10 species each. This is the case for Fabaceae (85 species), Poaceae (41), Rubiaceae (40), Asteraceae (28), Malvaceae (18), Combretaceae (17), Acanthaceae (15), Moraceae (15), Lamiaceae (14), Apocynaceae (13), Anacardiaceae (11), Annonaceae (10), and Phyllanthaceae (10) (Figure 3). Dominant life forms are phanerophytes represented by sudano-zambian species and the sudanian element-base. 14 species (2.76 % of the flora) show a relative frequency of at least 40 %: Isoberlinia doka (69 %), Andropogon tectorum (57.7 %), Rottboellia cochinchinensis (55.5 %), Ximenia americana (49.7 %), Olax subscorpioidea (49.3 %), Desmodium triflorum (48.4 %), Ozoroa insignis (48 %), Launea nudicaulis (48 %), Ozoroa pulcherrima (42.6 %), Pavetta lasioclada (42.2 %), Uvaria chamae (42.2 %), Pavetta corymbosa (41.7 %), Isoberlinia tomentosa (41.3 %), Dalbergia africana (40 %). 144 species (28.2 %) show a relative frequency comprised between 6 and 39 % (Adenodolichos paniculatus, Pterocarpus erinaceus, Aspilia bussei, Millettia thonningii, Canthium multiflorum, Uapaca togoensis, Trachypogon spicatus, Hypoestes strobilifera, etc.). Finally, 350 species have a relative frequency of less than 5 %. This distribution of specific frequencies with a domination of two woody species (I. doka, I. tomentosa) indicates that the populations sampled are floristically nearly homogeneous with the variations linked to site ecological conditions. Ecological factors variability and human alteration support the emergence of species with wide geographical distribution.