The living world Flashcards
How does afforestation help reduce desertification?
> slows movement of rain water to soil can absorb more
>roots hold soil together reducing risk of it being eroded
How can soil management help reduce desertification?
> encourages people to reduce grazing animals and grow crops instead
crop rotation means the same nutrients aren’t removed from the soil
How can using appropriate technology help reduce desertification?
> stone lines trap soil that is transported by wind so it isn’t eroded
reduces flow of water so more water enters soil
what is desertification?
process of fertile land turning into a desert over time
How does climate change cause desertification?
hotter and drier conditions increase the risk
How does deforestation cause desertification?
> the removal of trees leads to roots dying
>The soil will no longer be held together by the roots and erosion will occur
How does overgrazing cause desertification?
> vegetation is removed by grazing animals so soil becomes bare
soil becomes prone to drying out and cracking
How does over-cultivation cause desertification?
> as population grows demand for food also does
Farming becomes more intensive so less time for soil to recover
soil becomes infertile and exposed to erosion
What are the impacts of deforestation in the Amazon rainforest?
Economic development
Climate change contributions
Soil erosion
How does deforestation impact soil erosion?
> Exposes soil to heavy rain
rainfall washes nutrients and thin top soil away
forested slope lost 0.3 tonnes of soil a year
bare slope lost 139 tonnes of soil
How does deforestation contribute to climate change?
> slash and burn releases CO2 into the atmosphere
>Amazon’s overall ability to soak up CO2 dropped by 30% from the 1990s to the 2000s increasing global emissions by 21%
How does deforestation affect economic development?
> Deforestation threatens 57% of the 15,000 Amazonian tree species
clear trees for soybean, cattle and sugar canes
crop fields and pastures quickly decline in fertility due to soil erosion and then abandoned and cleared so economic benefits short lived
