Biology - Ecosystems

Ecological systemsBiosphere

Atmosphere

Lithosphere

Hydrosphere

Ecosphere

Biomes

Ecosystems with similar abiotic factors

Biomes 2 Canada

AustraliaDry arid Temperate forest Temperate reef

Ecosystems

HabitatParticular area in which a population lives

Abiotic factor Non living factors eg temperature, rainfall

PopulationAll the organisms from one species in an ecosystem

CommunityAll the organisms in an ecosystem

Environment All the abiotic factors

Biotic factorLiving factors eg predation, competition

Ecosystem is a term that describes ecological systems consisting of interacting organisms and their physical environment

Microhabitats Smaller areas within a habitat with slightly different conditions

Ecological termsAutotroph makes own food (either by photosynthesis or chemosynthesis) = producerHeterotroph eats other organismsProducer makes own food (either by photosynthesis or chemosynthesis) = autotrophConsumer eats other organismsDecomposer feeds of wastes or dead animals = detrivoreDetrivore feeds of wastes or dead animals = decomposerDetritus wastes or dead matterFirst order consumer eats producersSecond order consumer eats 1st order consumers

Respiration manufacture of energy by burning organic compounds eg glucosePhotosynthesismanufacture of organic compounds eg glucose using the energy of the sunChemical energyEnergy gained from chemical reactions eg respirationThermal energyHeat energySolar energyEnergy from the sunTrophic level location on food chain eg producer

NicheDescription of an organism’s role and or location within an ecosystem

Eg the fox can be described as 2nd order consumer or forest floor dweller

Food chains

• Arrows show movement of energy• The direction of the arrow is from organism

being eaten to the organism doing the eating

Food webs

• Arrows show movement of energy• The direction of the arrow is from organism being eaten

to the organism doing the eating

Abiotic factors – both aquatic and terrestrialFactor Effect on survival Measurement

Temperature Temperature affects cell activity – especially enzymes and reactions in the cell.

At low temperatures, cellular reactions slow. As the temperature increases the rate of reactions increases.

At extremely high temperatures, enzymes and structures can be damaged and the cell can die.

If the cell freezes, ice crystals can burst the cell

Thermometer

Light Light is necessary for photosynthesis.

It is affected by water depth and shade (eg trees).

Light meter

pH (soil or water) pH affects cell survival by altering proteins. This can damage cell membranes and enzymes in the cell.

pH meter

indicators

Salinity (soil or water) Salinity affects water and ion movement into and out of cells. High salt conditions dehydrate cells, low salt conditions can cause cells to swell and burst

Salinity meter

Conductivity meters

Wind Wind affects wave action in aquatic environments and humidity and water loss in terrestrial environment.

Wind meter

Anemometer

Abiotic factors – mainly aquaticFactor Effect on survival Measurement

Wave action Wave action affects the amount of gases (oxygen and carbon dioxide) that can dissolve in the water. The greater the action, the more gases dissolve.

Height in metre (swell)

Water currents These affect the temperature of water at different levels. They can carry nutrients from estuaries and coasts to deeper water.

Radar and infrared satellites

Buoyancy This is a measure of how easy it is to float. It is affected by salinity – the greater the salt content, the more buoyancy there is.

Viscosity This affects movement. The more viscous a material, the more effort is needed to move through it.

Turbidity This is a measure of small particles in the water (eg silt). High turbidity can reduce light penetration and interfere with gill function making it harder to survive.

Secchi disc

Depth The deeper the water, the less light penetrates. The wavelength of light also varies – red penetrates the least far & violet the most.

Sonar

Plumb line

Gases Oxygen is needed for respiration, carbon dioxide is needed for photosynthesis

Dissolved oxygen meter

Chemical tests

Abiotic factors – mainly terrestrial

Factor Effect on survival Measurement

Amount of water All organisms need water to survive Rain gauge

Humidity This affects water loss from leaves and the effectiveness of sweating and panting (evaporative cooling) in animals

Humidity meter

Hygrometer

Mineral salts (in soil) Plants need minerals to grow. Mineral salts affect salinity Salinity meter

Chemical tests

Soil type This is mainly determined by particle size, mineral salts and organic matter present. These affect water retention, fertility and the type of plants that will grow.

Soil tests

Topography Features such as slope, hills, valleys affect water movement, soil formation or erosion, shade and altitude. All of these affect the growth of plants and the animals they can support.

Inclinometers

Mapping instruments

Altitude Height above sea levels affects oxygen and carbon dioxide levels. Soil quality is also generally less at higher altitudes.

Mapping instruments

Biotic factors – role in ecosystem

• Autotroph – makes its own food

• Producer – provides energy to a food chain by photosynthesis (using light to convert carbon dioxide and water into sugars) or chemosynthesis (using chemical reactions to make energy or organic compounds)

• Heterotroph can not make its own food, so must eat other organisms

• Consumer – gains its energy by eating other organisms

• Decomposer – gains its energy by feeding on dead or decaying living matter

Biotic factors – feeding relationships

• Herbivore – eats plants • Carnivore – eats animals • Detrivore – eats dead or

decaying matter• Saprophyte – eats dead or

decaying matter • Predator – animal that eats

another • Prey – animal species eaten

by predator • Parasite – lives or feeds in or

on a host without killing it• Host – organism that a

parasite feeds on

Biotic factors – associations

• Competition – rivalry between two organisms/species for the same resources

• Collaboration - working together so both benefit but they can work without each other

• Mutualism – an association where both species benefit and both need each other eg lichen

• Commensalism – an association where one species benefits and the other is unaffected eg epiphytic ferns

• Pollination - animal species spread pollen for flowering plantsand are rewarded by food eg bees and nectar

• Dispersal – animal species spread seeds for a plant eg prickles or after eating the fruit

• Communication – signals are shared that allow individuals to recognise members of their group, possible mates or rivals or information about food or danger