Sahel, drylands area

Question 1

where is the Sahel?

Answer 1

extends from West to East Africa across ten nations eg Mali, Niger, Chad

Question 2

what physical threats are faced to food security in the Sahel?

Answer 2

increased periodic drought - limited amount of moisture leads to low productivity in the ecosystem + low biodiversity -> soils can not support agriculture + only xerophytes can survive

changes in rainfall pattern (linked to climate change) - heavy rain can quickly erode soils

exposure to high winds - scarcity of vegetation means high winds in winter can remove moist air around plants + soil, soil erosion can remove organic matter from surface layers leaving a sandy infertile soil

Question 3

what human threats are faced to food security in the Sahel?

Answer 3

pop. growth - pop = 920 mill in sub saharan Africa, annual demographic growth rates 2.5-4%. it will continue to grow beyond the regions capacity to feed itself. this growth + plus temp change of 3-5C could mean agricultural production fall by 50%

increasing deforestation - fuel wood needed for population + settlement growth -> increased wind + water erosion + loss of organic matter

overgrazing - overuse of land to grow crops, soil does not have time to recover + infertility leads to crop failure

land grabbing - agribusinesses looking to acquire land in Sudan for agricultural production. this displaces indigenous farmers with no legal land tenure, many migrate to towns as drought + famine intensify on marginal land

Question 4

what is marginal land?

Answer 4

land that has little or no agricultural or industrial value.

Question 5

what are xerophytes?

Answer 5

any plant adapted to life in a dry or physiologically dry habitat