ecology (T8) Flashcards
state the levels of organisation in an ecosystem
individual, population, community, ecosystem
what is an ecosystem
the interaction between living (biotic) and non-living (abiotic) part of an ecosystem
what factors do plants compete for
- light
- space
- water
- minerals from the soil
what factors do animals compete for?
- food
- mates
- territory
what is intraspecific competition
competition within a species
what is interspecific competition?
competition between different species
what is interdependence
different species depend on eachother for resources, if one species is removed the whole community may be affected
what is a stable community
a community in which all the biotic factors (the different species) and all abiotic factors are balanced so that population sizes remain relatively constant.
what are abiotic factors
non-living factors
what are biotic factors
living factors
what abiotic factors may affect an ecosystem
- light intensity
- temperature
- moisture
- soil ph and mineral content
- wind intensity and direction
- carbon dioxide level
- oxygen level
why might light intensity affect an ecosystem
different species of plant may have different optimum light intensities for growth
why does temperature affect an ecosystem
different animal and plant species may have different optimum temperatures for growth and survival
hoe does soil ph affect an ecosystem
certain plants may grow better in either alkaline or acidic soil, soil ph may affect the colour of the plant e.g. hydrangea
how does moisture level affect an ecosystem
certain plants cannot survive in waterlogged soil as their roots cannot respire
certain plants are adapted to high moisture levels
how does wind intensity affect an ecosystem
plant seeds are more likely to germinate in places in locations with lower wind intensity, which may also attract animals that depend on the plant to live nearby
how does soil mineral content affect an ecosystem
more plants require a high soil mineral content to grow well
example of a type of plant that has adapted to low soil mineral content
carnivorous plants catch insects to compensate for the low level of soil mineral content
how does CO₂ concentration affect an ecosystem
higher CO₂ conc. leads to more plant growth
how does O₂ conc. affect an ecosystem
aquatic animals cannot survive in areas with low O₂ conc.
state the biotic factors that make up an ecosystem
- food
- new predators
- new pathogens
- competition
what sre adaptations
features that enable organisms to survive in their living environment
what are organisms living in extreme environments called
extremophiles
what are three examples of extreme living environments
- high temp.
- high pressure
- hish salt conc.
an example of where extremophile bacteria can be found
in deep sea vents
what are plant adaptations to avoid getting eaten
- thorns
- unpleasant taste
- poison
plant adpatations for getting enough light
- grow/attach on other plants plants to get more sunlight
- reproduce earlier than other plants liek trees so they don’t have leaves yet
- has a larger surface area
plant adpatations for reducing water loss
- smaller surface area + thick waxy cuticle
- store water in their stems (succulent) and have extensive long and shallow roots
- curled leaves, hair and stomata sunken in plants trap moist air which reduces conc. gradient
marram grass for last one
what are structural adaptations
involving the form and structure of an organsim
what is a functional adaptation
involving the way the body of an organism works
what is a behavioural adaptations
involving changes to programmed or instinctive behaviour
animal adaptations in cold environments
- being large - creates a small SA:V ratio which reduces heat loss
- Blubber and thick fur coat - very effective insulation reducing heat loss
example fo a general animal adaptation
camoflauge - predators can blend into background to be able to stalk prey and prey can blend in to hide from predators
animal adpatation for dry/hot envrionments
- v. concentrated urine - need little or nothing ot drink + get water they need from food they eat
- active early in monring or night - to avoid hottest hours of the day
- rest in burrows and shadded places - shielded from the sun
- small - large SA:V ratio which increases heat loss
- large thin ears - larger SA exposed ton surrounding so more heats is lost from skin.
what is random sampling
- estimating pop. size over an area and for looking at the diff. in abundance of a species between two areas
what is abundance
the numbers of an organism relative to the number of other organisms in the same habitat
what is a transect
used to see if there is a correlation between an abiotuc factor and species distribution
what do food chains show
the feeding relationships between differnet organisms and the flow of energy between organism
what is biomass
total mass of living material
dis/advantaged of dry biomass
- better value
- however unethical as it involved killing and drying out organism
- wet biomass vice versa
what are trophic levels
the stages of a food chain
what do the arrows in a food chain represent
the direction of biomass transfer
what is a producer
an organism that makes its own food
what type of organisms are producers
green plants and algae
what is a primary consumer
organism that eats the producer
what is a secondary consumer
an organism that feeds on primary consumers
what is a tertiary consumer
an organism that feeds on secondary consuemrs
what is a predator
an organism that eats and kills other animals
what is prey
an organism that is eaten and killed by other animals
what is the pattern of predator and prey in stable communities
the numebrs of predators and prey rise and fall in steady cycle
why are producers the first trophic level
- provide all biomass for the food chain
- rest of food chain involves transfer of this biomass
what apparatus is used to measure abundance and distribution of a species in an area
quadrat
what apparatus is used to study the distribution of a species along a gradient
belt transect
describe how materials cycle through the abiotic and biotic components of an ecosystem
- organisms take in elements from their surroundings (soil, air)
- elements converted to complex molecules becoming biomass
- elements transferred along food chains
- elements returned to environment during excretion and decompostion of dead plant/animal material
3 molecules which are cycled through ecosystems
oxygen, carbon dioxide and water
explain the carbon cycle
- Carbon enters the atmosphere as carbon dioxide from respiration and combustion.
- Carbon dioxide is absorbed by producers to make carbohydrates in photosynthesis.
- Animals feed on plants, passing the carbon compounds along the food chain. Most carbon they consume is exhaled as carbon dioxide during respiration. The animals and plants eventually die.
- Dead organisms are eaten by decomposers and carbon in their bodies is returned to the atmosphere as carbon dioxide. In some conditions decomposition is blocked. The plant and animal material may then be available as fossil fuel in the future for combustion.
why is the carbon cycle important
molecules containing carbon such as glucose are important for living organisms to grow and provide energy for vital functions
what is the water cycle
- transpiration - this works to send water taken in by the roots of the plants back into the atmosphere as water vapour.
- Evaporation. Water evaporates, changing state from liquid to gas, from bodies of water, such as lakes and oceans and ponds. Light energy from the sun causes this.
- Condensation. After evaporation and transpiration, the water vapour cools, forming liquid clouds.
- Transport. When liquid clouds are formed, they can be pushed far distances by wind.
- Precipitation. Rain, snow, sleet and hail fall from the clouds into the bodies of water and the land.
- Surface runoff. Sometimes, when there is a large amount of precipitation, water runs along the earth to enter bodies of water.
- Infiltration. Some water that falls is absorbed into the ground. It can then be stored in aquifers. These are underground, permeable rocks
why is the water cycle important
living organisms require water, it provides them with a continuous supply of water(land)
why are microorganisms important for material cycling through an ecosustem
microorganisms return carbon to the atmosphere by releasing CO2 through respiration when decomposition of dead matter and returns mineral ions back to the soil
what is meant by decomposition
the breaking down of dead materials into simple organic matter
how to decomposers break down dead material
they release enzymes which catalyse the decomposition of dead matter into simple molecules
what are the two types of decompostion
- aerobic
- anaerobic
what factors affect rate of decomposition
- oxygen availability (for aerobic)
- water content
- temperature
how does the availability of oxygen affect rate of decomposition
oxygen increases, rate increases and vice versa
how does soil water content affect rate of decomposition
- in moist condition rate is high
- in waterlogged soil, little oxygen for respiration so rate is lower
why does decomposition require water
alllows for secretion of enzymes and absorption of molecules
how does temperature affect decomposition
- rate highest at 50 optimum temp.
- lower temp. means slower enzyme rate decreases
- higher temp. enzyme denatures, decomposition stops
rate of change?
change of value/ change of time
what is compost
nutrient-rich product of rapid decay of waste biological material in optimum conditions
how is compost used
as a natural fertiliser to promote growth of crops or garden plants
how do biogas generators work
uses methane gas for fuel through anaerobic decomposition occuring in animal waste
how do environmental condition affect communities
- affect abundance and distribution of organisms
- rising global temp has led to extinction of frog species
how do diff temps affect communities
- if temp too low growth will be slower as organisms use more energy maintaining body temp
- if temp too high evaporation increases, less water, organisms can die
how can changes in water level affect ecosystems
animals may have to migrate to find water and habitats such as ice caps may be destroyed
how can atmospheric gases affect ecosystems
some organisms cannot survive when certain gases are present and polluted water can cause illness
negative impacts of sulfur dioxide on environment
formed when fossil fuels containing impurities are burnt and can dissolve in water to form acid rain which can damage buildings and crops
negative impact of carbon monoxide on environment
formed by incomplete combustion of fossil fuels, can bind irreversibly to haemaglobin preventing it from carrying oxygen - can cause death
5 greenhouse gases
- water vapour
- methane
- carbon dioxide
- CFCs
- nitrous oxide
3 human activities contributing to GHGs
- burning fossil fuels
- deforestation
- large scale livestock farming
negative effects of global warming
- sea levels rise
- disrupted farming and agriculture
- increased spread of diseases in warmer climates
what is biodiversity
the variety of different species on earth or within an ecosystem
what is the importance of biodiversity
to maintain stability of an ecosystem
- it reduces the dependence on one species for resources such as food and shelter so they can still survive without it
why have humans consumption of resources and waste production increased
- rapid pop. growth
- increase in standard of living
where does pollution occur
- air
- land
- water
example of water pollutants
- sewage
- fertiliser
- chemicals
how does eutrophication occur
fertilisers from farms pollute water causing excessive algae growth which depletes oxygen in water causing other animals and plants to die. dead organic material attracts decomposers which depletes even more oxygen
example of air pollutants
- smoke
- acidic gases
example of land pollutants
- landfill waste
- chemicals
how do human activities reduce available land for plants and animals
- building
- quarrying
- farming
- disposing of waste
why have peat bogs been destroyed
increase food production as they can be used as fertilisers
why does the destruction of peat bogs contribute to the greenhouse effect
peat bogs are stores of carbon (carbon sinks) and burning them releases great volume of it back into the atmosphere
why have large scale deforestation occurred
- provide land for cattle or rice fields
- grow crops to use as biofuels
harmful effects of deforestation
- destruction of habitats
- releases large amount of GHGs
consequence of global warming
- rising sea levels
- melting ice caps
- changing weather patterns
- migration of animals
- tropical diseases
- extinction of species
steps taken to increase/maintain biodiversity
- breeding programmes for endangered species
- protection and regeneration of habitats
- reduction of deforestation and CO2 emissions
- recycling resources
- reintroduction of hedgerows and field margins
purpose of replanting hedgrows and field margins
higher biodiveristy in the margings than the fields that they are surrounding
how do you calculate efficiency of biomass transfer
[ energy transferred/total available ] x 100
