It lies within the forest/savanna transition zone. The dominant vegetation is a rather uniform type of dry Borassus-Combretum woodland; several rocky hills in the west bear some dry deciduous forest or transition woodland. There are several broad galleries of dry semi-evergreen rain forest crossing the reserve from north to south.
While savanna woodlands are rather poor (with only seven Sudanian biome endemics), the forest avifauna is surprisingly rich, with at least 36 Guineo-Congolian endemics (Appendix 1). Some of these were previously unknown from Ghana east of the Volta, e.g. Dryotriorchis spectabilis and the rail Himantornis haematopus (both discovered later in 2005 at Kyabobo), the latter being unexpectedly common in dry Diospyros mespiliformis forest. The bee-eater Merops malimbicus is a localized Guineo-Congolian species which is particularly common at Kalakpa; it is not yet known to breed in Ghana but there is circumstantial evidence that it might do so in the Kalakpa area. Further investigation is needed.
BirdLife International (2020) Important Bird Areas factsheet: Kalakpa Resource Reserve. Downloaded from http://www.birdlife.org on 01/10/2020.