KQ2 - Why are hot arid / semi-arid environments considered to be ‘fragile’? Flashcards
(34 cards)
how does wind make arid areas fragile
Strong winds and shifting sand create unstable surfaces that make it difficult for vegetation to grow
roots of plants in arid
shallow to grab immediate rainfall or deep to find underground water
size of plants like in arid / semi-arid areas?
Size: tend to be small and sparse
size of animals like in semi-arid / arid areas?
small to reduce water loss and maximise heat loss e.g. gerbil
Where is Arches National Park
SE Utah, USA
How many visitors visit the park annually?
1 million
How much rain does Arches National Park receive?
230 m annually
How many stone arches does Arches National Park have?
less than 2000
eg of Flora in arches national park
Yuccas: drought resistors; spines and hairy leaves which reduce exposure to air currents and solar radiation … limiting water lost to evapotranspiration; long taproots that can reach water beyond the reach of other plants
how does lack of veg make arid areas fragile
Lack of vegetation exposes the soil to wind and water erosion
Without vegetation, little organic matter is created that would normally decompose to release plant nutrients
how does evaoporation make arid areas fragile
High evaporation from rain, runoff and groundwater makes soil saline
how does soil quality make arid areas fragile
Hard, salty crusts impede root growth
how does lack of precipitation make arid areas fragile
Soils are thin and infertile because lack of precipitation limits chemical weathering processes
how does drought/lack of water make arid areas fragile
Animals and plants suffer when exposed to long periods of drought
how does wind affect eco systems
Strong winds and shifting sands create unstable surfaces that make it difficult for vegetation to become established.
what is cryptobiotic soil?
Cryptobiotic soil, small ecosystems on top of the desert floor, die under any vertical pressure. They form a ground cover just a few cm thick.
where is cryptobiotic soil found
arches national park, utah, usa
plant stems in arid
Stems: store water e.g. cacti
leaves in arid
small and waxy or thorns to reduce water loss and protect plant. Leaves may die off in dry season
reproduction in arid plants
often very bright flowers to attract the few pollinators. Use wind or animals to spread their seeds
stomata of arid plants
stomata closed in day to lower evapotranspiration
what is CAM
crassulacean acid metabolism (CAM) which allows them to photosynthesise when close their stomata
habits of arid animals
nocturnal, hibernate in dry season or burrow to restrict water loss
colour of arid animals
light to reflect heat and blend into background sand/dust e.g. camel, fennec fox