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Monitoring land-cover changes in semi-arid regions: remote sensing data and field observations in the Ferlo, Senegal
by A. Diouf and E.F. Lambin
Dryland degradation rarely translates into linear, declining trends in vegetation cover due to interannual climatic variability. Appropriate indicators of land-cover modifications need to be defined for semi-arid regions.
Our hypothesis is that degradation can be measured by:
- (1) a decrease in the resilience of vegetation to droughts;
- (2) a decrease in rain-use efficiency; and
- (3) a modification of floristic composition.
The objective of this paper is to test the relationships between a remotely sensed indicator of vegetation, rainfall data and field measurements of biomass and floristic composition.
The study was based on field measurements of vegetation conditions covering a period of 10 years, in the semi-arid region of the Ferlo in Senegal.
Our results indicate that land-cover modifications in the Ferlo are best measured by changes in rain-use efficiency. No consistent trend in the relative abundance of grass species was visible at the scale of the decade, even on the two sites affected by degradation. Just after a drought, a given increase in rainfall results in less biomass production than is the case for normal years.
Read the full article: Science Direct