Biodiversity & Food Production Flashcards
what is biodiversity?
the variety of all the different species of organisms on earth or within an ecosystem
what does a great biodiversity ensure?
a more stable community
stability of ecosystems by reducing the dependence of one species on another for food, shelter and maintenance of physical environment
what does the future of human species on earth rely on?
maintaining high biodiversity
what human activities are reducing biodiversity?
waste
deforestation
global warming
land use
peat use
chemicals (that cause pollution)
what programmes are there to reduce negative impact of humans on ecosystems & biodiversity?
breeding programmes for endangered species
protection & regeneration of rare habitats
reintroduction of field margins & hedgerows in agricultural areas where farmers grow one type of crop
reduction of deforestation & carbon emissions by some governments
recycling resources rather than dumping waste in landfill
why is there an increase in the amount of waste being produced & what does this cause?
increase in world population & increase in standard of living
= more resources are used
causes more pollution
where can pollution occur?
in water - from sewage, fertiliser or toxic chemicals
in air - from smoke (inc. CO2) & acidic gases
on land - landfill & toxic chemicals
how does pollution reduce biodiversity?
kills plants & animals
describe the process of eutrophication in 7 steps
- sewage & fertilisers (have high conc. of nitrate ions) wash into lake or river
- algae on surface grow faster (bc more mineral ions so faster ps)
- aquatic plants are shaded by algae (no light = no ps)
- some aquatic plants die = less ps = less O2 released into water for aerobic respiration by aquatic organisms e.g. fish
- dead algae & plants decomposed by microorganisms
- microorganisms aerobically respire, using up O2
- aquatic animals (fish & invertebrates) suffocate & die & repeat step 6
how do humans reduce amount of land available for other animals & plants?
building
quarrying
farming
dumping waste
why destruct peat bogs & areas & what does this cause?
for garden compost
reduces area of peat habitat
= reduce variety of plant, animal & microorganism species that live there
= reduce biodiversity
what happens when peat is burned?
release CO2 into atmosphere
compost vs conservation
cheap compost for food production
vs
conserve peat bogs/peatland to preserve biodiversity & reduce CO2 emissions
why has large-scale deforestation in tropical areas occurred?
to provide land for cattle & rice fields
to grow crops for biofuels
- both produce methane (greenhouse gas)
what is the consequence of deforestation?
carbon locked as wood is released during burning - CO2 released into atmosphere
dead tree stumps are decomposed/broken down by microorganisms that respire to release CO2 into atmosphere
loss of habitat = reduce biodiversity
what contributes to global warming?
increasing levels of CO2 & methane in atmosphere
how do we know global warming is happening?
systematic reviews of thousands of peer reviewed publications
describe the greenhouse effect
- solar radiation reaches earth
- some radiation is reflected from earth’s surface
- greenhouse gases (e.g. CO2 & methane) absorb some of this energy so less radiation is reflected out of earth’s atmosphere
some is re-radiated in all directions including to earth’s surface keeping earth warmer than it would otherwise be
do not talk about ozone layer!
what can increase in earth’s temperature cause?
changes in earth’s climate - more severe & unpredictable weather patterns
rise in sea level - ice caps & glaciers melting can cause flooding
reduction in biodiversity - due to extinction
changes in animal migration patterns
changes in distribution of species
oceans hold/sequester less CO2 - less efficient CO2 ‘sinks’
what is food security?
having enough food to feed a population
what biological factors threaten food security?
in some countries increasing birth rate = increases population
changing diets in developed countries = scarce food resources transported around the world
new pests & pathogens
environmental changes = can cause famine e.g. if no rain
cost of agricultural inputs
conflicts impact availability of water & food
how can efficiency of food production be improved?
by restricting energy transfer from food animals to environment: e.g. keep them inside
- limiting their movement
= lower rate of respiration to release energy for muscle contraction to move
= less glucose used up - controlling temperature of their surroundings
= lose less heat energy
= lower rate of respiration to keep warm (exothermic)
= less glucose used up
how can animal growth be increased?
high protein food
what are the advantages & disadvantages for intensive farming?
advantages: high input, high output
cheaper per serving
more efficient (less energy lost)
faster growth
less land needed per animal
more protected from weather
disadvantages: (vs opposite - free range)
ethical objections & think reduced animal welfare
higher costs of lighting, heating, antibiotics etc.
higher disease rate
more development issues in animals
