Ecosystems 2 Flashcards
What is the Climate of Hot Deserts?
- Little rainfall
- Extreme temperature
- Day - 45 degrees Celsius
- Night - 5 degrees Celsius
What is the Soil like in Hot Deserts?
- Shallow w/ gravelly texture
- Not fertile
- Dry from lack of rain
What are the Plants like in Hot Deserts?
- Growth sparse from lack of rain
- Cacti & thornbushes grow
- Short plants except cacti
- Short life cycle
What are Animals like in Hot Deserts?
- Contain animals adapted to survive in harsh environment
- Lizards, snakes, insects, scorpions
- Mammals small & nocturnal
- Most birds leave desert during harshest conditions (roadrunners live all year)
What are People like in Hot Deserts?
- Grow a few crops
* Indigenous people often nomadic
What are the Biotic components of Hot Deserts?
- Plants
- Animal
- People
What are the Abiotic components of Hot Deserts?
- Climate
- Water
- Soils
How are Plants and Animals linked in Hot Deserts?
- Plants get nutrients from soil, providing nutrients & water for animals to eat
- Animals spread speeds, help plants reproduce
How do Plants Struggle to Grow in Hot Deserts?
- Hot dry climate affects soil
- Soil salty from high evaporation & low nutrients from little decomposition of dead plant material by fungi & bacteria
Why can Hot Deserts only support low density populations of animals?
Sparse vegetation limits amount of food available
What can Soil Erosion lead to?
Clouds of dust in atmosphere - changes climate of deserts - reducing rainfall making them even drier
How can you cause Soil Erosion in Hot Deserts?
Cattle overgraze vegetation
Describe Cacti:
- Succulents
- Big, fleshy stems to store water
- Thick waxy skin to reduce water loss
- Sharp spines & toxins to stop animals stealing water from stems
Describe Plant Roots:
Very long to reach deep water supplies, spread out wide near surface to get as much water when it rains
How are Desert Animals adapted to cope with Hot, Dry conditions?
- Nocturnal - animals stay cool
- Long limbs or ears - large SA to lose heat from
- Big animals (camels) store large amounts of fat which break down to water when needed
- Minimise water loss from sweat and urine
How do Camels adapt to sand?
- Keep sand out of eyes & nose by having triple eyelids, long eyelashes & close nostrils
- Large flat feet so don’t sink in sand
Where is there the Highest level of Biodiversity and what does it Contain?
- Along desert margins
- Small areas around ephemeral ponds/rivers
- Contains high proportion of epidemic species to the desert
Why does Human Development threaten Biodiversity?
- Increasing desertification
* Over-using/contaminating water supplies
How does Global Warming affect Hot Deserts?
- Deserts hotter & drier
- Forcing species (lizards) to move to cooler areas
- Species at limits of environment don’t have anywhere to go, risk of decline/extinction
What is Desertification?
Degradation of land that becomes drier & less productive
How is Climate Change a Cause of Desertification?
- Reduce rainfall - plants die, soil easily eroded
* Higher temperatures - water evaporates from land & plants, drier soil, plants die
How is Human Activity a Cause of Desertification?
- Removal of fuel wood (cooking), soil exposed, soil easily eroded
- Trampling erodes soil
- Animals eat plants faster than they can grow - soil erosision
- Population puts pressure on land - deforestation (for firewood), more overgrazing & over-cultivation
How can you Reduce the risk of Desertification?
- Water management
- Tree Planting
- Soil management
- Appropriate technology
How does Water Management reduce the risk of Desertification?
- Grow crops that don’t need much water
* Drip irrigation on crops instead of surface irrigation - soil isn’t eroded by lots of water at same time
