Hot Desert Ecosystems and Biodiversity Issues - Paper 1 Flashcards
Are there high or low levels of biodiversity in deserts?
Low.
What are 3 environmental challenges for plants in hot deserts
-Dry conditions
-High temperatures
-Short periods of rainfall.
What are xerophytes?
Plants that can survive in very dry conditions.
How have xerophytes adapted to dry conditions in deserts?
Thick, waxy cuticles and the shedding of leaves to reduce transpiration and minimise water loss.
How have xerophytes adapted to high temperatures in deserts?
Some have the bulk of their biomass below the ground surface where temperatures are cooler.
How has biodiversity adapted to short periods of rainfall in deserts?
Deserts bloom suddenly after rainfall so complete their life cycle quickly.
What are 4 types of plant adaptations?
-Drought-tolerant trees
-Cacti
-Flowering plants
-Lichen
What is an example of a drought-tolerant tree?
Acacia trees.
Name 3 adaptations of acacia trees for survival in hot deserts:
-Short fat trunks to act as reservoirs for excess water
-Fire resistant
-Their roots can penetrate 50m into the ground and reach out sideways to find as much water as possible
What is another name for cacti?
Succulents.
What are 3 adaptations of cacti for survival in hot deserts?
-They store water in their tissues
-They have spikes to deter consumers
-Small waxy leaves to minimise transpiration losses
What does lichen appear as?
A flaky crust on the ground, rocks and tree trunks.
What species name are lichens also called?
Why are they called this?
Pioneer species, because they do not need soil to grow.
What 2 poor conditions can lichens grow in?
Bare rock surface and high temperatures.
What is an example of a cactus and a fact about it?
The USA’s saguaro cactus can grow up to 15 metres.
How do lichens survive?
They chemically break down rock using their own organic acids, this helps them to extract nutrients they need.
What are the names of 2 consumer species who have adapted to hot desert regions?
-Kangaroo rats
-Desert foxes
What are 4 adaptations of kangaroo rats?
-Do not need to drink water, they get it from food
-Live in burrows during the day do avoid extreme heat
-Do not perspire
-Highly effective kidneys which produce very little urine.
What are 2 adaptations of desert foxes?
-Thick fur on the soles of their feet, protecting them from the hot ground
-Light-coloured fur to reflect sun light and keep them cool
What is the interdependence between vegetation to help soils in deserts?
-Roots stabilise sandy soils.
-Plants stop the soils from being blown away by the wind.
-Plants provide shade to stop soil losing water
-Plants reduce chance of desertification
What is the interdependence between soils to help plants in deserts?
-Soil can provide some nutrients and water for plants
-Soil provides structure for roots
What is the only carnivore in the Saharan desert that is able to survive without free water?
Fennec fox.
Give 5 adaptations of the fennec fox:
-Large ears - help lose excess body heat through radiation
-Adapted kidneys to restrict water loss
-Extensive burrowing may cause dew, which can be consumed
-Thick fur to help insulate them in cold desert nights
-Sandy fur helps reflect heat and also provides excellent camouflage
