Formation of forest islands in West Africa has been linked to
anthropogenic soil improvement resulting in luxuriant tree growth in
otherwise open savanna landscapes. However, there is limited understanding
of how such unique ecosystems modulate soil carbon (C) dynamics and
nutrient cycling. In this study, we report soil nutrient characteristics
and two distinct soil organic carbon pools of Anogeissus grove (forest
island) associated with abandoned village sites of the Mole National Park
in the Guinea savanna or tropical continental climatic zone of Ghana,
taking opportunity of a previously published study in Biotropica in 1978.
We compared present-day differences in soil characteristics between the
previously studied forest grove and adjoining open savanna in the Park and
evaluated vegetation dynamics since first measurement in 1974. Overall, we
see changes related to self-thinning and expansion of the grove on a
decadal timescale. Soil organic matter and available phosphorus contents
were greater in the grove and increased by 19.6 and 18.7%, respectively
over time, showing persistence after four decades. Mineral associated
organic carbon (MAOC) differed significantly (p<0.05) between the
vegetation types, being 3.44% in the grove and 2.34% in the savanna. The
grove was ca. 25% greater in particulate organic carbon (POC) content than
the savanna. In both vegetation types, >55% of carbon was
stabilized in the mineral fraction. Our study demonstrates long-term human
impacts on soil and vegetation and offers a clear nature-based solution
for climate change mitigation through sustainable land management by
indigenous people towards achievement of the ‘4p1000’ initiative.