Ecology and conservation
The type of ecological habitat may have a possible effect on the morphology of L. columnaris (Mabberley 1974b). This observation has to be developed in future studies. Our study observed that populations grow in a mosaic of ecological habitats, latitudinal, and elevational gradients. Indeed, we observed phenotypic variation in some traits, for example, in plant height, size of the inflorescence, leaves, and flower colour. L. columnaris is smaller in height, inflorescence, and leaf length at a higher elevation (approx. 3000m) and lower elevation (1000m). Elevations between 2000 to 2600m, the variation is spectacular with greater height, inflorescence number, colour, and leaf length.
The populations of L. columnaris in mainland Cameroon are at high risk of local extirpation because of excessive anthropogenic pressure on montane forest fragments. Only for the populations on Mt. Cameroon, which is a National Park, have conservation protection plans. The scenario in Bioko for this giant lobelia and the Afromontane forest is better. Bioko has an active conservation procedure in two of the three sky islands (Müller & Pócs 2007). Moreover, South Bioko is undisturbed because of low human population density and supports the highest numbers of plant and animal species on the island (see Jones 1994).