B19 - ecosystems, habitat destruction, conservation Flashcards
define ecosystem
a unit containing the community of organisms and their environment, interacting together.
define habitat
an area where an organism lives
define population
all the members of the same species
define community
all populations of living organisms in a habitat
state the interactions in a ecosystem
community, habitat and environment all interact with each other. Community interacts with itself. This forms an ecosystem.
names the 2 environmental factors and their meaning
Biotic - living factors
Abiotic - non- living factors
what are the 2 types of abiotic things
Physical and climate
give examples of abiotic physical and climate
physical - light intensity, water availability, oxygen / carbon dioxide concentration
climate- temperature, humidity
give examples of biotic
diseases, mates, food, predators, community
define biodiversity
number of different species that live in an area.
state the 2 factors to measure biodiversity
-number of different species
-total number of individuals in that ecosystem
state where there would be high and low biodiversity and give a reason
High - tropical rain forest - plenty water, high temperature
Low - Deserts - high temperature, little water - Polar regions - low temperature, plenty water (frozen) - Urban regions - little space for plants to grow
What reduces biodiversity (11)
-urbanisation
-human activates - pollution, overharvesting, hunting, introduction of foreign species
-habitat destruction - deforestation, agriculture,
-climate change - global warming
Why do some ecosystems have a higher biodiversity
-more even spread of species
-greater total of organisms
how does monoculture affect biodiversity
-1 dominant species
- damages food web
reasons for habitat destruction (6)
-increased land use
-Marine pollution
-Fresh water pollution (discarded rubbish)
-Chemical waste
-extraction of natural resources
-Untreated sewage / fertilisers (Eutrophication)
Give the effects and examples of increased land use
eg. livestock production, crop production, urbanisation, factories
Effects:
-damages food web
-produce pollution
-decrease biodiversity
-increased green house effect
Give the effects and examples of marine pollution
eg. oil spills, plastics, nets hooks, eutrophication
Effects:
-disrupts food web
-microplastic - toxic to animals
-strangles / cuts animals (nets and hooks)
-decreased dissolved oxygen
Give the effects and examples of extraction of resources
eg. mining, stones, oil, wood, gas
Effects:
-disrupts food webs
-destroys habitats
-reduces biodiversity
-pollution
Give the effects and examples of chemical waste
eg. nuclear waste, heavy metals, pesticides
Effects:
-disrupts food webs
-bioaccumulation / biomagnification of heavy metals and pesticides
-kills top consumer
-mutations, cancer (nuclear waste)
-damaged nervous system and brain damage (heavy metals)
Give the effects and examples of fresh water pollution (discarded rubbish)
eg. plastic, cans, food waste, glass
Effects:
-strangles / cuts animals
-non biodegradable
-smells and spread diseases
-cause forest fires
Give the effects and examples of untreated sewage / fertiliser
eg. human waste, animal waste, nitrate fertiliser
Effects: Eutrophication
-increased plant growth in water (algae bloom) and blocks light
-decomposers feed on dead algae
-decomposer population increases and use up dissolved oxygen
-animals die from lack of oxygen
define bioaccumulation
build up of chemical in body (fat)
define biomagnification
concentration of chemical increases with each tropic level
define biodegradable
cannot break down
define biological control of pests
introduction of foreign species
what are the disadvantage and advantage of biological control of pests
-advantage - no chemical added into the food web
-disadvantage - introduced species may not eat pests, native species cannot defend against invaders, have no natural predators
define deforestation
mass clearing of forests
4 effects of deforestation
-soil erosion
-flooding
-increased carbon dioxide in atmosphere
-extinction
explain soil erosion from deforestation
-no roots to anchor soil
-leeching - unused nutrients and minerals will be washed away
-harder to regrow trees
explain extinction from deforestation
-habitats destroyed
-loss of biodiversity
-fewer producer
explain increased carbon dioxide in atmosphere from deforestation
-trees store carbon which is released when burning trees
- less photosynthesis which removes carbon dioxide from atmosphere
explain flooding from deforestation
-rain will not hit leaves and slow down
-loose top soil - risk of flash flooding and landslides
-roots absorb water
explain climate change from deforestation
-reduced transpiration and direr atmosphere - affect water cycle and reduced rainfall
-thermal gradients - raised temperature in lower atmosphere from rapid heating of adsorption - more intense and frequent winds
how is climate change a threat to biodiversity
-change in temperatures and environmental conditions that animals cannot adapt to
how is hunting a threat to biodiversity
-removal of organisms - risk of extinction
-disrupts food web
how is overharvesting a threat to biodiversity
-more removal of organisms than reproduction of them
-disrupts food web
-population is unsustainable
how is habitat destruction a threat to biodiversity
-fewer organisms can be supported
how is pollution a threat to biodiversity
-destroys habitat
4 ways for conservation
-monitoring and protecting endangered species
-educate
-breeding in captivity programs
-seed banks
How does seed banks help conversation
-keeps seed of endangered species
-keeps seeds dry and cold to prevent germination
-protects and maintains plant genetic diversity
How does captive breeding programs help conversation
-lower infant mortality rate - easier to re-establish population
-prevent extinction
-some species are let out in wild to re-establish population
How does educating help conversation
-teach people the importance of conservation and how they can help
How does monitoring and protecting endangered species help conversation
-easier to identify which species are at risk
-development of land is restricted
-protected areas protect animals and habitats
how does deforestation affect concentration of CO2 in the atmosphere
-less photosynthesis happens
-less CO2 removed form atmosphere
