Savannah ecosystem, why biodiversity in the savannah is under threat, how people use the savannah, Lake Chad. Flashcards
Where is the Savannah grassland ecosystem found?
Within the tropics 5-15 degrees north and south of the equator, between tropical forests and hot deserts
What is the Savannah grassland ecosystem also known as?
Semi-arid grassland
Does the wet season in the savannah occur in the summer or winter?
Summer
The rainfall in the savannah is concentrated for how many months of the year?
5-6 months
Xerophytes are plants that…
Can survive drought
Pyrophytes are plants that …
Adapted to tolerate fire
How has the Acacia tree adapted to live in the savannah
Broad flat canopy reduces water loss, thorns on branches to stop animals from eating them, large roots to get water from deep underground, Small leaves with waxy skins to reduce the amount of water lost through transpiration.
Why is the savannah a popular tourist destination?
Animals, Plants, Insects - Safari
Why are there less stores of nutrients in the savannah than in the rainforest?
Shorter growing season and fire returns carbon to atmosphere.
Due to the high temperatures what happens to the organic matter?
Decays rapidly
What does fire important to maintain the savannah ecosystem?
It maintains the grass community and mineralises the litter layer, kills weeds and prevents trees from growing.
What are the most important nutrient recyclers?
Termites
Episodes of drought in the savannah last for……..months of the year.
4-8 months
Why is the savannah significant in the global carbon cycle?
They cover 20% of earth’s land surface so despite having significantly less trees than rainforests or temperate forests they are significant in the carbon cycle. Regular bushfires release many tonnes of CO2 into the atmosphere
Give an example of a producer in the savannah ecosystem
Grasses, Acacia Tree
Give an example of a primary consumer in the savannah ecosystem
Baboon, Rhino, Giraffe, Zebra
Give an example of a Secondary consumer in the savannah ecosystem
Cheeta, Hyena
Give an example of a tertiary consumer in the savannah ecosystem
Lion
What is the greatest threat to the animals in the savannah ecosystem
Poaching
What animal example of poaching did we study
Rhino for their horns
Give 3 potential solutions to reduce the poaching problem of rhinos
De horn the Rhino, Poison the horn with dye, Manufacture synthetic Rhino horn, Make use of drones, Fix GPS and Camera in Rhino Horns
What is desertification?
The spread of the desert, or desert conditions.
What are the three main reasons for desertification?
Slash and burn of the savanna trees and bushes to make space for farming reduces evapotranspiration and so eventually leads to a reduction of water. The removal of vegetation means that leaf litter can no longer fall into the soil therefore the nutrient cycle is broken and the shrubs no longer replace nutrients.The destruction of the tree canopy exposes the soil to rain splash erosion. On steeper slopes the power of the water carries material which then erodes downwards this is called gulley erosion.
What two types of farming take place in the African savannah?
Arable Farming (Crop) Pastoral Farming (animals)
What is a fallow period?
Field is left to regain its nutrients
What has happened to Lake Chad?
Significantly reduced in size
Why has Lake Chad reduced in size?
Deforestation in the lakes drainage basin causing a drier climate. The over-abstraction of water from the rivers both for domestic supply (in cities) as well as intensive farming and irrigation. 20 dams have been built in northern Nigeria.
What have been the impacts of Lake Chad reducing in size on people and environment?
Cholera and Polio as people relying on the lake for their water, Salinisation of soil, Wetland ecosystem has dried out so birds and fish populations have declined, Migration to cities such as Kano.
Give 2 ways that the transaqua project could save Lake Chad
Transfer water from the Democratic Republic of Congo via a canal between the River Congo and River Chari, Generate Hydroelectric Power which would create opportunities for people and tackle poverty.
