fragile environments Flashcards
what makes the environment more fragile
volcanic eruptions
humans
high winds
fires
name the three processes that impact the fragile environments
desertification
deforestation
climate change
what does the term desertification mean
when productive land changes into dessert like land
where does it usually take place
near semi-arid land near deserts
name 6 factors affecting desertification
- absence of surface water
- dried up ponds
- vegetation loss
- increase in soil erosion
- increase in salt in the soil
- more loose sand
what is deforestation
the cutting down of trees
what is logging
cutting trees down for timber
whats clear felling
if a forest is completely cut down
whats selectie felling
if some trees have been left behind
why does rainfall effect desertification
no rainfall causes vegetation to die and leaves bare soil
why does soil erosion effect decertifications
removal of soil means less support and nourishment for vegetation
why does population growth affect desertification
pressures on land to grow more food
how does migration effect desertification
when groups of people migrate they settle down and theres an increase in food demands
what does overgrazing do
too many cattle, sheep and goats can destroy vegitation
what are 5 reasons why trees cut down
- logging
- agriculture
- mining
- land for farmers
- road building
whats the source of CO2
fossil fuels are burnt
burning wood
deforestation (tree removal )
what are the sources of methane
decay of organic material
animal manure
what is the source of nitrous oxides
burning fossil fuels
artificial fertiliser
how does desertification impact the soil
the soil dries up and erodes and eventually turns into dust which gets blown away
how does desertification impact agriculture
the conditions means that the productivity is lowered. crops fail an animals die
how does desertification impact the population
malnutrition, starvation and famine
how does deforestation cause flooding
the eroded soil deposits in the rivers which means it floods
how does deforestation cause leaching
removing the trees leaves the soil bare, the rainfall then washes away the nutrients
how does deforestation effect the animals
it leaves them without a habitat
how does deforestation effect the tribes
they are forced to-move away into smaller land which then clears up
