Human influences on ecosystems Flashcards
how have humans have increased food
production. name examples
-agricultural machinery to use larger areas of
land and improve efficiencient
- chemical fertilisers to improve yields
- insecticides to improve quality and yield
- herbicides to reduce competition with weeds
- selective breeding to improve production by
crop plants and livestock
Describe the advantages of
large-scale monocultures of crop plants
farmers benefit from higher profits
high efficiency
technology advances
specialized production
simpler to manage
Describe the disadvantages of
large-scale monocultures of crop plants
destroys soil nutrients
pollutes groundwater supplies
uses a lot of fossil fuel energy
requires a lot of water to irrigate
destroys overall soil degradation and erosion
Describe the disadvantages of
intensive livestock production
increases risk of disease and pest outbreaks
upsets natural balance of soils since if too many of the same plant species in one field area rob the soil of it’s nutrients resulting in decreasing verities of bacteria and microorganisms that are needed to maintain fertility of the soil
Describe the advantages of
intensive livestock production
crop yield is high
helps farmer to easily supervise and monitor land
protection from livestock from being hurt
Define biodiversity
the number of different
species that live in an area
Describe the reasons for habitat destruction. Name examples
- increased area for housing, crop plant
production and livestock production - extraction of natural resources
- freshwater and marine pollution
How can humans have a negative impact on habitants in our biodiversity
through altering food webs and food
chains
Explain the undesirable effects of deforestation
as an example of habitat destruction
reducing biodiversity,
extinction,
loss of soil,
flooding
increase of carbon dioxide in the
atmosphere
Describe the effects of untreated sewage and
excess fertiliser on aquatic ecosystems
nutrient rich materials from fertilizers(especially nitrogen and phosphorus) and waste materials cause eutrophication in both fresh and marine ecosystems
Describe the effects of non-biodegradable
plastics, in both aquatic and terrestrial
ecosystems
they’re eaten by terrestrial animals which further chokes and gets trapped in the digestive system of the animals
plastics get accumulated in organisms and is passed down the food chain- increasing amount of each higher trophic level which is known as biomagnification
they last for long period of times
they can disintegrate into smaller pieces and form microplastics and accumulate in the environment and remain in the ecosystem for a very long time
can cause habitat destruction- plastics can cover the sunlight for photosynthesis to occur or plastic can also block the roots and prevents root growth.
Describe the sources and effects of pollution of
the air by methane and carbon dioxide
the enhanced greenhouse effect and climate
change
Explain the process of eutrophication of water
- increased availability of nitrate and other
ions - increased growth of producers
- increased decomposition after death of
producers - increased aerobic respiration by decomposers
- reduction in dissolved oxygen
- death of organisms requiring dissolved
oxygen in water
Define a sustainable resource
one which is produced as rapidly as it is removed from the
environment so that it does not run out
Can some resources can be conserved and
managed sustainably? Give an example and explain
