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Floodplain rehabilitation in North Cameroon: Impact on vegetation dynamics
Author(s) -
Scholte Paul,
Kirda Philippe,
Adam Saleh,
Kadiri Bobo
Publication year - 2000
Publication title -
applied vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.096
H-Index - 64
eISSN - 1654-109X
pISSN - 1402-2001
DOI - 10.2307/1478916
Subject(s) - perennial plant , floodplain , tussock , vegetation (pathology) , environmental science , flooding (psychology) , transect , grassland , grazing , belt transect , ecology , agronomy , geography , biology , medicine , psychology , pathology , psychotherapist
. Since the construction in 1979 of a dam in the Logone floodplain in the Sahelo‐Sudanian zone of Cameroon, annual inundations have decreased, reducing perennial vegetation as important grazing source for nomadic herds and wildlife during the dry season. Presently, possibilities exist to release excess water for floodplain rehabilitation. In 1994 a pilot release was executed, reflooding 200 km 2 , to verify predicted advantages. Vegetation has been studied from 1984 onwards along a transect covering flooded, recently reflooded and desiccated parts of the floodplain. Since 1993, the floristic composition has also been monitored in a grid in the centre of the impact zone. Cover of perennial grasses, most notably Echinochloa pyr amidalis and Oryza longistaminata increased from 41 to 61% in the reflooded zone. Vetiveria nigritana , a tussock grass that used to be dominant, disappeared slowly after the dam construction and has not shown a comeback. The cover of annual species, most notably Sorghum arundinaceum , a dominant annual grass only since the mid‐1980s, decreased in the reflooded zone from 58% to 34%. If the present conversion rate of annual into perennial grassland is extrapolated, recovery towards a 100% perennial state may be reached after the 2003 flooding season. Apart from favourable climatic conditions, recovery might be dependent on the restoration of soil fertility, limiting an approach focusing on flooding depth only.