The unusual presence of enclosed humid savannas in the tropical rainforest of Cameroon: A study of the past and present environmental dynamics

Near Akonolinga town in Cameroon, some enclosed savannas of 175 km2 are found within the rainforest. Those savannas are very strange at this latitude ( 3°46’ N, 12°20’W) with humid climatic conditions (1529 mm/a). Although those savannas are burned every year by peasants, and sometimes for hunting purposes, they are rarely hited by bush fires which are halted at the boundaries by a natural double fire-break made up of Zingiberaceae and a famous Asteraceae plant called Chromolaena odorata. Nowadays, this second plant is playing a typical role in the forest encroachment by surpressing the savanna gramineae ( Imperata cylindrical ) and favourising the growth of pioneer forest species ( Albizia spp.) Despite the forest advancement observed, occurring at highly variable rates from 0 to 7 m/a in Akonolinga savannas, and from 0 to 15 m/a in other sites in Cameroon, some forest boundaries had been maintained unchanged between 1952-1984.

Today, the Geographical Institute of Bern University, in partnership with the Department of Geography-Environment-Development of Dschang University in Cameroon, wants to initiate a research project to study the possible reasons for the savanna distribution. As a hypothesis, the savanna areas might be related to poor soil conditions, or, they might be relicts of former dry climatic conditions during the Holocene or even the Upper Pleistocene. Therefore, the Upper Quaternary soil-, landscape- and climate evolution of the Akonolinga region will be studied. Besides the scientific interests, the results will give new insights into the savanna ecosystem, possibly influencing further land use and management practices in the region.

Within the framework of this planned cooperation, it is conceivable that a number of Master/Diploma Thesis will be undertaken by Geographical students, both from Bern and Dschang Universities. A first step is the three months visit of Philippe Tchomga at the Geographical Insitute in Bern.

Contact:
Philippe Tchomga
Institute of Geography
University of Bern
Hallerstrasse 12
CH-3012 Bern
phone: +41/031-6318561
tchomga@giub.unibe.ch
ptchomga@yahoo.com

Prof. Heinz Veit
Institute of Geography
University of Bern
Hallerstrasse 12
CH-3012 Bern
veit@giub.unibe.ch

Prof. Martin Kuete
University of Dschang
Fac. of letters and social sciences
Dept. Geography-Environment-Development
B.P. 49 Dschang
phone: +237 7735870
cerehtuds@yahoo.fr