DRYLANDS Flashcards
What are the characteristics of dry land precipitation?
2 general
Arid - less than 200mm average across 20% of the land surface.
Semiarid - between 200-500mm average across 25% of the land surface.
Negative water balance.
Great variability in precipitation.
What is the difference between aridity and drought?
Aridity - average conditions of limited rainfall and water supplies.
Drought - prolonged variability from the normal conditions.
What are 4 biomes inside arid areas?
Steppe
Savanna
Desert
Mediterranean
What are the 3 most common types of land use for agriculture?
Rangelands at 88%.
Rain fed crop
Irrigated field
What are the ecological adaptations for perennial and annual plants?
Perennial lose leaves and have deep roots.
Annual plants can lie dormant as seeds until rain arrives.
What are some modernisation approaches applied in drylands and how are they bad for the environment?
Settlement schemes - can’t follow rains, so plants that rely on disturbances and fertilisation may disappear.
Introduction of fencing, wells, non native plants - can lead to invasive species outcompeting.
What livelihood strategies do pastoralist communities use?
Utilising a mix of resilient species and emphasising their products.
Mobile pastoral systems.
Enabling mobility through infrastructure.
State sponsored redemption.
What are the ecological concepts of equilibrium and carrying capacity?
Carrying capacity - the number of species an area can support.
Equilibrium - the balance between the agents acting in an ecosystem.
What are the limits to the CC and E concepts in drylands?
Lack of data and colonial stereotypes lead to these terms being misused. Lead to cullings of herds and restriction of land use in order to protect land, but the system was functioning just fine without help. So these terms are useless.
