Ecology Flashcards
define habitat
a place where the organism lives
define population
all the organisms of one species living in a habitat
define community
the populations of different species living in a habitat
what are abiotic factors?
non-living factors of the environment, eg temperature
what are bioitc factors?
living factors of the environment eg food
define ecosystem
the interaction of a community of living organisms ( bioitc) with the non-living (abioitc) parts of their environment
what do plants need from their environment in order to survive and reproduce?
light, space, water and mineral ions from the soil
what do animals need from their environment and other organisms in order to reproduce?
space ( territory), food, water and mates
what do organisms compete with other species for?
the same resources
what is the concept of interdependence?
when each species in a community depends on the other species for things such as food, shelter, pollination, and seed dispersal
why does any major change in an eco-system have far reaching effects?
because of interdependence
name 7 abiotic factors
- moisture level
- light intensity
- temperature
- carbon dioxide level
- wind intensity and direction
- oxygen level
- soil ph and mineral content
describe the impact of an increase of decrease of an abiotic factor?
these changes could affect the size of populations in a community, and therefore affect the population size of other organisms that depend on them
what impact may a decrease in light intensity, temperature or carbon dioxide have within an eco-system?
it could affect plant growth, and this could cause a decrease in the population size
what could a decrease in the mineral content of the soil lead to?
nutrient deficiencies, which could then affect plant growth and cause a decrease in the population size
name 4 biotic factors
- new predators
- competition between species
- new pathogens
- avaliability of food
what are structural adaptations?
features of an organisms body structure such as shape or colour
what is the structural adaptations of an artic fox?
they have white fur so they are camouflaged against the snow, this helps them avoid predators and sneak up on prey
what structural adaptaions do whales have?
they have a thick layer of blubber and a low surface area to volume ration to help them retain heat
what structural adaptations do animals that live in hot places have?
they have a thin layer of fat and a large surface area to volume ration to help them lose heat
what are behavioural adaptations? give some examples ;)
ways that organisms behave - many species migrate to warmer climates during the winter to avoid the problems of living in cold conditions
what are functional adaptations?
things that go on inside an organism’s body that can be related to processes like reproduction and metabolism
what functional adaptations may desert animals have?
they may conserve water by producing very little sweatr and small amounts of concentrated urine
how are brown bears functionally adapted?
they hibernate over the winter, and they lower their metabolism which conserves energy, so they do not have to hunt when there’s not much food around
food chains always start with a…?
producer
what do producers do?
make their own food using energy from the sun ( usually green plants or algae)
what is a plants biomass?
biological molecules made in a plant from glucose, its basically energy stored in a plant
how is energy transferred through living organisms in an ecosystem?
when organisms eat other organisms
producers are eaten by…
primary consumers
primary consumers are eaten by….
secondary consumers
secondary consumers are eaten by…
teritary consumers
what are predators?
consumers that hunt and kill other animals
the population of any species is usually limited by the avaliability of what?
food
as the number of predators increase…
… the number of prey will decrease
why are predator-prey cycles out of phase with each other?
because it takes a while for one population to respond to changes in the other population
how can you study the distribution of an organism?
- measure how common an organism is in two sample areas
- study how distribution changes across an area
both these methods give quantatibe data about the distribution
what is a quadrat
a square frame enclosing a known area
how do you compare how common an organism is in two sample areas?
- place a 1 m^2 a quadrat on the ground at a random point within the first sample area ( eg divide area into a grid and use a random number generator to pick coordinates)
- count all organisms within the quadrat
- repeat steps 1 and 2 multiple times
- work out the mean number of organisms per quadrat within the first sample area
- repeat steps 1 to 4 in the second sample area
- compare the 2 means
how do you use transects to help find out how organisms like plants are distributed across an area?
- mark out a line in the area you want to study using a tape measure
- collect data along the line
- you can do this by counting all the organisms your’e interested in that touch the line
- or, you can use quadrats, by placing them along the line or at intervals
name 3 environemntal changes that can affect the distribution of organisms
- change in availability of water
- a change in the temperature
- a change in the composition of atmospheric gases
explain the water cycle..
- energy from sun makes water evaporate from the land and sea, turning it into water vapour
- water evaporates from plants via transpiration
- as warm air rises, warm water vapour is carried upwards, and then when it gets higher up it cools and condenses to form clouds
- water falls from clouds as precipitation onto land where it provides fresh water for plants and animals
- it drains into the sea before the whole process starts again
define biodiversity
the variety of different species of organisms on Earth or within an ecosystem
why is high biodiversity important?
- it gives stability to ecosystems, because different species are dependent on eachother for things like shelter and food
- different species can also help maintain the right phsycial environment ( eg the acidity of soil)
describe human popultaion patterns
the population of the world is currently rising very quickly - exponentially
why are we seeing such a big rise in human poultation?
due to modern medicine and farming methods that means less people are dying from disease and hunger
what are the impacts of the exponentially rising population?
- puts pressure on the environment as we take resources needed to survive
- people are demanding a higher standard of living ( consequences: use more raw materials, more energy for manufacturing)
- resources are being used up faster tham they are being replaced
how is water pollution created?
- sewage and toxic chemicals from industry can pollute lakes, rivers and oceans, affecting the plants and animals that rely on them for surivial
- chemicals we use on land can be washed into water
how is land pollution created?
- we use toxic chemcials for farming
- bury nuclear waste underground
- dump household waste of landfill sites
how is air pollution created?
- smoke and acidic gases released into atmosphere can pollute the air
- sulfur dioxide can cause acid rain
describe how gases in the atmosphere acrt like an insulating layer…
gases in the atmosphere absorb most of the enrgy that would normally be radiated out into space, and re-radiate in all directions ( including back towards the earth) the increases the temperature of the planet
what are the two main greenhouses gases? ( that are rising quite sharply)
carbon dioxide and methane
what is the difference in global warming and climate change?
global warming refers to the overall increase in the earths temperature, and climate change is a consequence of global warming and refers to the effects on the climate ( eg shifts in weather patterns)
what is the difference in climate and the weather?
climate describes the typical weather conditions in an entire region for a very long time, whereas weather refers to short term atmospheric conditions ( eg whether it is rainy or sunny on a paticular day)
how does global warming effect our oceans?
- causes sea water to expand
- causes ice to melt
…. so sea level rises.. could result in the flooding of low-lying places = loss of habitat
how does global warming impact the distribution of plant species and wild animals?
- distribution or animals and plant species may change due to change in temperature and rainfall
- species that need warmer conditions may spread further
- species may become less widely distributed that need cooler temperatures
- ultimately reducing biodiversity
define deforestation
the cutting down of forests
why may deforestation happen?
- to clear land for farming
- to grow crops from which biofuels based on ethanol can be produced
explai n why less carbon dioxide is taken in as a result of deforestation?
- cutting down lots of trees means amount of carbon dioxide taken in from photosynthesis is reduced
- trees lock up lots of carbon, so less trees means less carbon is ‘locked up’
how does deforestation lead to more co2 being in the atmosphere?
- carbon dioxide released when trees are burnt to clear land
- microrganisms feeding on dead bits of wood respire to release carbon dioxide
how does deforestation lead to less biodiveristy?
- habitats like forests can contain a variety of different species so when they are destroyed there is a danger these can become extinct, reducing biodiveristy
what are bogs?
- areas of land that are acidic and waterlogged
- anaerobic conditions mean that plants don’t fully decay in bogs, they turn into peat
how are bogs carbon sinks?
- the carbon in the plants is stored in the peat, instead of being released into the atmosphere
what are peat bogs used for?
- often drained so that the area can be used as farmland
- peat is cut up and dried to use as fuel
- sold to gardners as compost
explain how the drainage or burning of peat contributes to global warming?
- when it is drained it comes into more contact with air, and some microrganisms start to decompose it, when these microrganisms respire they use oxygen to release carbon dioxide
- also released carbon dioxide when burned as fuel
how can breeding programmes be used to prevent endangered animals from becoming extinct?
- animals bred in captivity to make sure they survive if it dies in the wild
- sometimes individuals can be released into the wild to boost or re-establish a population
what are some of th ehabitats that may be protected or regenerated through a programme?
rare habitats like mangroves, heathland and coral reefs
how do field margins and hedgerows increase biodiversity
they provide a habitat for a wider variety of organisms that could survive in a single crop habitat ( through wildflowers, diffeent grasses etc)
how can governments help protect ecosystems and biodiversity?
regulations and programmes to reduce the level of deforestation, and the amount of CO2 being released by bussinesses
why are ppl encouraged to recycle?
- to reuced amount of wate getting dumped into landfill
