B19 - Human influences on ecosystems Flashcards
describe ecosystem
a unit containing the community of organisms and their environment, interacting together
describe biodiversity
the number of different species that live in an area
what are 3 main reasons for habitat destruction?
-increased area for housing, crop plant production, and livestock production
-extraction of natural resources
-freshwater and marine pollution
what are 5 undesirable effects of deforestation?
-reducing biodiversity
-extinction
-loss of soil
-flooding
-increase of carbon dioxide in the atmosphere
what is an example of habitat destruction?
deforestation
what are 6 reasons why a species might become endangered?
-climate change
-habitat destruction/loss of habitat
-hunting
-overharvesting
-pollution
-introduction of non-native / foreign / alien species
endangered species can be helped by what 4 conservation measures?
-education (programmes)
-captive breeding (programmes)
-monitoring and legal protection of endangered species
-seed banks
what are abiotic factors? give 5 examples
non living factors
-temperature
-oxygen
-CO2
-light intensity
-water availability
what are biotic factors? give 4 examples
living factors
-predators
-food
-plants
-animals
where would high biodiversity be found in an environment?[3]
lots of different species which show a lot of variation and are living in, all evenly distributed across the study area
what are 3 human activities that are reducing biodiversity in ecosystems?
-waste production
-deforestation
-global warming
what 3 things do you use to calculate relative biodiversity?
-number of different species in an area
-total number of individuals in an area in an ecosystem
-even spread/distribution
if theres an even spread/distribution, what happens to the biodiversity?
increases
what are 3 ways that reduce biodiversity?
-monoculture (farming)
-over harvesting
-climate change/global warming/pollution
how does monoculture affect biodiversity?
theres a dominance of 1 species, not a variety, so biodiversity decreases
describe monoculture
a field of one crop
why are pesticides harmful to wildlife?
they don’t break down, they pass up the food chain and the pesticide level increases as it goes up the food chain
where is the DDT stored in the organism?
fatty tissue