factors effecting biodiversity Flashcards
(23 cards)
what is causing an increase in the factors effecting biodiversity
-over double the humans now than in the 1960’s
-due to improvements in medicine, housing, etc
what does the need to make space for the human population result in
-deforestation
-agriculture to feed
-climate change
-other pollution (chemicals, littering, noise, light)
whats an example of natural deforestation
forest fires
what does deforestation do
-reduce tree numbers
-if only one type of tree then this reduces species richness
-reduces animal species
-forced migration of animals can impact biodiversity elsewhere
how does deforestation reduce animal species
-destruction of habitats and food sources
why is reforestation not effective
-only commercially valuable species reforested
-doesn’t really solve the problem
why does farming reduce biodiversity
farmers only grow commercially viable plants or animals
what do farmers do in order to maximise production
-deforestation for space
-remove hedges for space
-large machinery
-use of chemical pesticides and herbicides
-create mono culture
what’s a monoculture
-crop consisting of only one strain of the species
why is monoculture a problem
-limited genetic diversity
-easier to harvest
example of monoculture
-85% of palm oil grown in Malaysia and Indonesia
whats selective breeding
-when farmers select particular traits
-such as rapid growth, high protein content
how does selective breeding reduce biodiversity
-other characteristics are ignored
-genetic diversity of species declines
-other breeds die out and cause genetic erosion
what is climate change
a rise in the earths mean surface temperature
how much of the heat do oceans absorb
-80%
what does climate change cause
upwards trends of precipitation
effects of climate change on biodiversiy
-melting ice caps
-rising sea levels
-increased drought
-insect and pollinator life cycle changes
what does melting ice caps cause
-extinction of highly adapted species
what do rising sea levels cause
-flooding of low lying land
-saltwater flowing up rivers
-intrusion into terrestrial and freshwater habitats
effects of increased drought on biodiversity
-reduces species survival
-increases dominance of xerophyte communities
what does reducing the size of habitats and population mean
-the species has less capacity to adapt to changing conditions through evolution
-leave isolated and fragmented populations that are too small to survive
what does modern agriculture rely on to be efficient
-monoculture
-selective breeding
what leads to the migration of populations towards the poles
-climate change causes a reduction of genetic diversity
-less able to adopt along with climate change
-only alternative is to move and follow the climate patterns
