Vegetation and vegetation dynamics strongly impact global and regional water cycles affecting both, climate (see chap. I-5) and water availability (see chap. I-6). Furthermore, land cover and land use have a significant impact on the sustainability of resource management and socio-economic factors such as food and income production and human migration. The actual vegetation cover in Benin and Morocco is very diverse (described in detail in sect. I-3.6). Vegetation dynamics are caused by seasonal climate changes, altered soil properties, human land management which is driven
by economic factors. In addition to seasonal vegetation dynamics, in both study areas the expansion of land use has modified or even eliminated natural vegetation causing land degradation in several regions. Particularly in the Drâa catchment in Morocco, extensive grazing, irrigation with subsequent salinization as well as firewood collection have degraded vegetation cover and plant diversity. In Benin, human activities have altered the current species composition of savannas and have negatively impacted forest regions. In Central Benin, increased agricultural activities and bush fire frequency have significantly changed the vegetation cover within recent years.