Studies
A small number of studies on land use and cover sequence have been undertaken
in West Africa (Akin 1958; Clayton 1958), while extensive studies have been
conducted on nutrient cycling under shifting cultivation (Nye and Greenland
1960).
The general observations suggest that the ecological succession concept is
applicable. Clayton (1958) described the secondary vegetational sequence from
forest to savanna near Ibadan in Nigeria. He observed three trends of
cultivation succession:
- normal rotation of cultivation-thicket-secondary
forest-recultivation;
- degeneration in the nature of the fallow as a
result of frequently repeated cultivation;
- decline of cocoa plantations
as the canopy opens by die-back as inter cultivation commences.
Ahn (1958) has described land use and cover development in relation to
vegetational sequences, bushfires and bush fallow cultivation in the western
forest areas of Ghana. Rose-Innes (1964) has also described the land use
processes leading to land degradation in the savannas of northern Ghana (fig.
14.1). In these studies the vegetational sequences are emphasised rather than
the land use
sequences.
