Ecology Flashcards
what is biodiversity?
the variety of all the different species of organisms on earth
species depend on each other for what?
food and shelter
spices help to maintain the environment, for example……
decomposers break down the remains of dead organisms
what does a high level of biodiversity mean?
there are lots of different species, making an ecosystem more stable
what does a stable ecosystem mean?
lots of different species mean that the ecosystem is less dependent on one species, so if the population of the species falls, it is less likely to affect the whole ecosystem.
what is an example of humans having a negative effect on biodiversity?
deforestation - tropical forests contain a very rich biodiversity, large area of these forests are being destroyed, to provide land.
what is the land from deforestation used for?
rice fields or for grazing cattle
grow crops which are used to make biofuels
what does sewage contain?
urine and feaces
what happens in some countries to sewage?
it is released into nearby waterways
what happens to sewage in the uk before being released?
sewage is treated
impact of sewage in biodiversity (water pollution)
in some cases untreated sewage (faeces and urine) is accidentally released into rivers or streams, untreated sewage causes dissolved oxygen levels to fall, killing aquatic organisms, which reduces the number of species resulting in an unstable ecosystem that is more dependent on certain species.reducing biodiversity
impact of farming in bioviersity (water polloution)
fertilises from farms can be released into rivers and streams, this causes dissolved oxygen levels to fall, killing aquatic organisms, which reduces the number of species resulting in an unstable ecosystem that is more dependent on certain species.reducing biodiversity
impact of factories on biodiversity (water pollution)
sometimes toxic chemicals from factories are released into rivers, which can kill animals in the river, which reduces the number of species resulting in an unstable ecosystem that is more dependent on certain species. reducing biodiversity.
air pollution example:
burning coal in power stations, can release acidic gasses, which can cause acid rain.
burning can also release smoke, air pollution like this can kill plants and animals, this reduces biodiversity.
land polloution:
millions of tons of waste are dumped into landfills, landfills destroy habitats for plants and animals. toxic chemicals can also leach out of landfills and pollute the soil. these chemicals kill living orgainsms
what should we do to reduce pollution?
carefully handle waste materials, and dispose of them without harming the environment
what do humans use land for?
buildings (houses, airports, shops and factories)
what other ways do humans use land?
farms quarries landfills
what does the use of land mean for animals
there is less land available for animals and plants, due to this reduction in habitats, biodiversity is decreased
Peat: what do peat bog and lands contain?
large amounts of dead plant materials
is decay fast or slow in peat
decay is very slow
what do peat bogs and lands contain?
trapped carbon
what is happening to peat habitats?
they are being destoryed
what is peat used to produce?
cheap compost for gardens and farms
what is peat used to produce in some countires?
peat is burned to release energy for example to generate electricity, this also releases carbon dioxide into the atmosphere
what is the destruction of peat lands reducing?
peat habitats, so reducing the plants and animals and microorganisms that live there so the destruction of peat is reducing biodiversity
what is another problem with peat?
once it has been extracted and used for compost, it begins to decay, this releases large amounts of carbon dioxide in the atmosphere.
what does released carbon dioxide contribute to
climate change
what have people done to reduce peat?
many gardeners have stopped buying peat free compost, but the alternatives are more expensive
if farmers had to use peat free compost then the price of food would go up
what is global warming?
Global warming is the gradual increase in the average surface temperature of the Earth. scientists believe that the current increase in temperature is due to human activity;Humans release carbon dioxide, burning fossil fuels. Methane - greenhouse gas, trap heat in atmosphere
what are the biological consequences of global warming?
Animals lose habitats, malaria brought to the UK as it’s hot enough for mosquitoes. Migration patterns change
what is peer review?
when papers have been checked by other scientists before being published. it helps to detect false claims, making sure everything is valid. however Reports in popular media are not peer reviewed, so can be biased inaccurate or oversimplified.
how can we maintain biodiversity?
Breeding programmes for endangered species
Protection and regeneration of rare habitats like wetlands
preventing global warming
reducing waste
ecosystem
the interaction of a community of living organisms (biotic) with the non living organisms (abiotic) PARTS OF THEIR ENVIRONMENT
what do plants need
light,space, water, mineral ions from the soil
what do animals need
space(territory) food, water,mates
what do organisms compete for?
organisms compete with other species and members of their own species for the same resources
what is interdependaence
in a community each species depends on other species for living things such as food, shelter, pollination and seed dispersal
what does the interdependence of all living things in a ecosystem mean
any major change can have far reaching effects
stable communities
environmental factors are in balance so population sizes are roughly constant, these include tropical rain forests and ancient oak woodlands
abiotic factors
moisture level
light intensity
temperature
carbon dioxide level (for plants)
wind intensity and direction
oxygen level (for aquatic animals)
soil pH and mineral content
example of how changes in abiotic factors affect plant populations
a decrease in light intensity, temperature or level of carbon dioxide could decrease the rate of photosynthesis in a plant species.
this could affect plant growth and cause a decrease in the population size
biotic factors
new predators
competition -one species may out compete another so that number are too low to breed
new pathogens
ability of food
why does changes in biotic factors have knock on effects
because of interdependence
what is an example of how changes in biotic factors affect animal populations
red and grey squirrels live in the same habitat and eat the same food. grey squirrels outcompete the red squirrels the population of red squirrels in decreasing
what are the different types of adaptations
structural
behavioural
functional
structural adaptations:
features of an organisms body structure such as shape or colour
an example of structural adaptions:
arctic animals like the arctic fox have white fur so they are camouflaged against the snow. this helps them avoid predators and speak up on prey
animals that live in cold places (like whales) have a thick layer of blubber and a low surface area to volume ration to help them retain heat
behavioural adapations:
the ways that organisms behave
example of behavioural adaptions
swallows migrate to warmer climates during the winter to avoid the problems of living in cold conditions
functional adaptations
things that go on inside an organisms body that can be relates to processes like reproduction and metabolism
example of functional adaptations
desert animals conserve water by producing very little sweat and small mounts of concentrated urine
brown bears hibernate in winter. they lower their metabolism, which conserves energy, so they dont have to hunt when there is not much food about
microorgaisns with adapations
some microorganism like bacteria are known as extremeophiles - they are adapted to live in extreme conditions
extremeophiles example
some can live in super hot volcanic vents ad other can live in places with a high salt concentration like very salty lakes or at high pressure like deep sea vents
what do food chains always start with
a producer - they make their own food using energy from the sun
eg of a producer
green plants or algea - thy make glucose by photosynthesis
what happens to some of the glucose made in photosynthesis
it is used to make other biological molecules in the plant ( these biological molecules are the plants biomass- the mass of living material)
what is biomass
energy stored in a plant
how is energy transferred through living orgainsms
when organisms eat other orgainsms
food chain:
producers are eaten by primary consumers
primary consumers are then eaten by secondary consumers
secondary consumers are eaten by tertiary consumers.
if the population of the prey increases
then so will the population of the predators
if the population of predators increases
the number of prey will decreases
when the number of rabbits goes up the number of foxes doesn’t increase immediately because…………..
it takes time for the foxes to reproduce
prey and predator cycles are always
out of phase with each other. this is because it takes time for one population to respond to changes in the other population.
ways of studying the distribution of an organism
measure how common an organism is in tow sample areas using quadrats and compare them
or
study how the distribution changes across an area, eg by placing quadrats along a transect
how do you compare how common an organism is in two sample areas
1) place a 1m square quadrat on the ground at a random point within the first sample are
2) count all the organisms within the quadrat
3) repeat steps 1 and 2 many times
4) wok out the mean number of organism per quardrat
5) repeat steps 1 -4 for the second quadrat, work out the mean then compare the two
what can you use transects to find
how organisms are distributed across an area eg if an organism because more of less common as you move from a hedge towards the middle of a field
how to use transects:
1) mark out a line in the area you want to study using a tape measure
2) collect data along the line
3) count all the organisms that you are interested in that touch the line
the water cycle:
1) energy from the sun makes water evaporate from the land and sea, turning it into water vapour. water also evaporates from plants - transpiration
2) the warm water vapour is carried upwards as warm air rises. when it gets higher up it cools and condenses to form clouds.
3) water falls from the clouds as precipitation (usually rain but sometimes snow or hail) onto land, where it provides fresh water for plants and animals
4) it then drain into the sea, before the whole process starts again
the water cycle:
1) transpiration
2) condensation
3) precipitation
4) evaporation
how are elements cycled back to the start of the food chain by decay:
1) living things are made of materials they take from the world around them. these get passed up the food chain
2) these materials are returned to the environment in waste product, or when organisms die and decay
3) materials decay because they get broken down by microorganisms. this happens faster in warm moist, aerobic conditions because microorganisms are more active in these conditions.
4) decay puts the stuff that plants need to grow (eg mineral ions) back into the soil
5) in a stable community, the materials that are taken out of the soil and used by plants etc. are balanced by those that are put back in.
condition where microorganisms are active
warm
moist
aerobic (oxygen rich)
the carbon cycle:
1) CO2 is removed from the atmosphere by green plants and algae during photosynthesis. the carbon cycle is used to make glucose which can be turned into carbohydrates, fats and proteins that make up the body of plants and algae
2) when plants and algae respire some carbon is returned to the atmosphere as CO2
3) when plants and algae are eaten by animals some carbon becomes part of the fats and proteins in their bodies. the carbon then moves through the food chain
4) when animals respire some carbon is returned to the atmosphere at CO2
5) when plants animals and algae die, other animals (detritus feeders) and microorganisms feed on their remains. when these organisms respire CO2 is returned to the atmosphere
6) animals produce waste that is broken down by detritus feeders and microorganisms
7) the combustion of wood and fossil fuels also releases CO2 back into the air.
8) so the carbon and energy is constantly being cycled - from the air through food chains (via plants, algae and animals and detritus feeders and microorganisms) and eventually back out into the air again
what has led to an increase in the worlds population
modern medicine an farming methods which have reduced the number of people dyeing from disease and hunger
what are the types of waste
water
land
air
water waste:
sewage and toxic chemicals from industry can pollute lakes, rivers and oceans, affecting the plants and animals that rely on them for survival (including humans)
chemicals used on land can be washed into water (fertilisers, pesticides and herbicides)
land waste:
we use toxic chemicals for farming (pesticide and herbicide)
we bury nuclear waste underground, and we dump a lot of household waste in landfill sites
air poloution:
smoke and acidic gases released into the atmosphere can pollute the air eg sulphur dioxide can cause acid rain
global warming
gasses in the atmosphere act as an insulating layer. they absorb most of the energy that would normally be radiated out into space, and re radiate it in all directions (including back towards the earth) this increase the temperature of the planet
consequences of global warming
sea levels rising
change sin species distribution
changes in migration patterns
reduction in biodiversity
sea levels rising:
1) higher temperatures cause seawater to expand and ice to melt, causing the sea levels to rise
2) it has risen a little bit over 100 years
3) for animals and people living in low lying places it will be detrimental
4) it will lead to flooding = loss of habitats
changes in species distribution:
1) the distribution of many wild animal and plant species may change as temperatures increase and the amount of rainfall changes in different areas
2) some species may become more widely distributed eg species that need warmer temperatures may spread further as the conditions they thrive in exist over a wider area
3) other species may become less widely disrupted eg species that need cooler temperatures may have smaller rangers as the conditions they thrive in exist over a small area.
changes to migration patterns:
eg some birds may migrate further north as more northern areas are getting warmer
reduction in biodiversity:
biodiversity could be reduces if come species are unable to survive a change in the climate so become extinct.
what do humans use land for?
building, quarrying, farming and dumping waste
peat bogs:
the carbon in plants is stored in the peat
when peat is drained is comes into contact with air and some microorganisms start to decompose it
when the microorganisms respire they use oxygen and releases
carbon dioxide, contributing to global warming.
carbon dioxide is also released when peat is burned as a fuel
destroying peat bags also means
destroying a habitat = reducing biodiversity
problems with deforestation
less carbon dioxide taken in - less photosynthesis
more CO2 in the atmosphere - co2 released with trees are burnt
less biodiversity - habitats destroyed - species become extinct
conflicting pressures that affect how biodiversity is maintained
the cost of programmes
effect on local economy
protecting food security
the development of society
the cost of programmes
protecting biodiversity costs money:
governments sometimes pay farmers a subsidy to reintroduce hedgerows and field margins to their land
it also cost money to keep watch and see if the programme is being followed correctly
sometimes money may be prioritised for other things
effect on local economy
it may come at a cost to peoples livelihoods:
people could be unemployed as their job might be cutting down trees
this could effect the local economy if people move away to find jobs
protecting food security
sometimes certain organisms are seen as pests by framers eg foxes and are killed to protect crops and livestock so that more food can be produced
as a result the food chain and biodiversity can be affected
the development of society:
land is in such high demand that previously untouched land with high biodiversity has to be used eg housing developments on the edges of towns
