Ecosystems Flashcards
Define population
A group of individuals of the same species living in the same place (habitat) at the same time
Define environment
Collective term for the conditions in which an organism lives
Includes abiotic and biotic conditions
Define biome
One of the world’s major ecosystems usually named after the dominant vegetation of the area
Can be terrestrial and aquatic
What are 8 different terrestrial biomes/ecosystems?
Tropical rainforest Scrubland Temperate rainforest Desert Open woodland Alpine Grassland (savannah) Sclerophyll forest
What are 4 different aquatic biomes/ecosystems?
Freshwater
Eg. Lake, billabong
Mangrove estuary
Marine
Eg. Coral reef, rock platform, deep sea
Estuarine
What are the two factors affecting the survival of an organism?
Biotic
Abiotic
What are biotic factors?
Living or biological factors that can affect the survival of an organism
What are abiotic factors?
Non-living or physical and chemical factors that can affect the survival of an organism
Examples of abiotic factors
pH of soil or water, temperature, turbidity, presence of dissolved ions or gases (O2, CO2, nitrates), availability of water, salinity in the soil/water, light intensity and humidity
Examples of biotic factors
Includes competition for food and nesting sites, predation, parasitism, food sources and disease causing pathogens or decomposes which break down the wastes.
What is Viscosity?
thickness of a medium e.g. water or air, and its ability to resist internal movement through it
What is the relationship between Viscosity and the organism?
The thicker the medium, the higher the viscosity and the more internal friction it offers to the organism
Viscosity affects the ability of an organism to move around.
How does viscosity compare on terrestrial and aquatic environments?
Water is more viscous than air so many aquatic animals are more streamlined than land animals so they can move rapidly through the water.
What are 7 comparisons between aquatic and terrestrial environments?
Viscosity Buoyancy Pressure Temperature variation Availability of gases Availability of water Light penetration
What is Buoyancy?
the force giving upward thrust.
How is buoyancy determined?
Determined by the density of the medium and determines the floating ability of the organism.
How does buoyancy compare on terrestrial and aquatic environments?
Air provides little upthrust, so most terrestrial organisms need a skeleton or a means to support their own weight.
Salt water provides more upthrust than freshwater.
What is pressure?
force exerted on a body by its medium.
How does pressure compare on terrestrial and aquatic environments?
In water pressure depends upon depth – the deeper the water the higher the pressure.
On land pressure depends on altitude – the higher the altitude, the lower the pressure
What is temperature variation?
is of importance, as many chemical reactions in the body are temperature dependent. Enzymes denature or become inactive with variations in temperature.
How does temperature variation compare on terrestrial and aquatic environments?
Usually temperature of water varies less than air temperature on land.
If the body of water is large e.g. ocean, temperature variation is much less than in a small body of water such as a small pond.
Water temperature decreases with depth
What does the availability of gases mean?
e.g. oxygen and carbon dioxide, and ions e.g. nitrates, phosphates and calcium ions. Such will determine whether a particular environment is suitable for a particular species.
How does availability of gases compare on terrestrial and aquatic environments?
Gases are more readily available in air than in water e.g. a litre of air contains 210 cm3 oxygen while a litre of water at 15 degrees C contains about 6 cm3 oxygen
Availability of gases also depends on the rate of diffusion – diffusion is greater in air than water.
How does availability of gases affect aquatic environments?
In water the amount of dissolved gases depends upon factors such as temperature, depth and turbulence.
Hot water holds less oxygen than cold water
What does availability of water mean?
major concern for animals and plants on land and in water
How does the availability of water affect terrestrial organisms
On land many organisms keep cool by the evaporation of sweat, but this can lead to dehydration.
The extent and depth of root systems of many land plants is determined by water availability
How does the availability of water affect aquatic organisms?
In aquatic environments water availability can be a problem due to osmosis. Organisms in salt water tend to lose water by osmosis.
Organisms in fresh water tend to gain water by osmosis.
How does the light penetration affect terrestrial environments?
especially important for plants for photosynthesis.
Most terrestrial environments have good light penetration.
Many plants have specific adaptations for full sun/partial sun/full shade.
Tropical rainforests have vertical levels with different amounts of light penetration, ranging from full sunlight at the emergent uppermost level to forest floor which receives very little sunlight.
How does the light penetration affect aquatic environments?
Aquatic habitats light penetration is a critical factor as light only penetrates to about 100 metres.
What are 3 samplers for biotic components?
Sweep nets Water samplers Plankton net Kick sampling Pitfall traps Longworth small mammal trap Pooter or aspirator Tullgren funnel Beating tray
What are 3 samplers for abiotic components?
Anemometers – wind speed
Thermometers – temperature
Barometers – atmospheric pressure
Rain gauges - rainfall
pH meter- acidity or basicity of an aqueous solution.
Dissolved oxygen content – oxygen levels
Wave action –
Light meter- light intensity
Hygrometer - humidity
Turbidity -amount of suspended material in water
Chemical testing kits – soil or water nutrients/salinity
What are the three things in ecosystems interactions that are continually occurring?
between the living (biotic) community and its abiotic surroundings.
within the abiotic surroundings
within the living community. Interactions within the community of an ecosystem may involve members of different species.
Give an example to the interactions that are continually occurring between biotic and abiotic factors.
eg. Plants capture light energy and take up carbon dioxide from the atmosphere and water and mineral nutrients, such as nitrates from the soil.
Give an example to the interactions that are continually occurring within the abiotic surroundings
eg. A lack of rainfall over an extended period causes the water flow in rivers to fall and creeks to dry out.
What are the 7 types of interactions within ecosystems?
Mutualism
Commensalism
Predator/prey
Parasite/host – endoparasite and ectoparasite
Collaboration
Competition – intraspecific and interspecific
Disease
What is symbiosis?
Symbiosis is a term for interactions in which two organisms live together in a close relationship that is beneficial to at least one organism.
There are three kinds of symbiotic relationship; mutualism, commensalism and parasites.
What are the three types of symbiotic relationships?
mutualism, commensalism and parasites.
What is a mutualism?
both organisms benefit from the relationship
Give 3 examples of a mutualistic relationship
Examples include: corals have a close association with a type of algae. The algae live, reproduce, photosynthesize and utilize waste products of the animal hosts (coral). In turn, the coral uses the oxygen and food produced by the algae to grow, reproduce and form its hard skeleton.
oxpeckers and zebras
eg. oxpeckers benefit by having a readily available source of food. While zebras benefit from having the bugs removed. Oxpeckers also fly high and make noise to alert nearby animals to the impeding danger
pistol shrimp and goby fish
the shrimp is able to dig a burrow to live in but is relatively blind and cannot detect approaching predators, the goby fish uses the burrow for protection from predators and in return acts as ‘eyes’ for the shrimp. In the day the shrimp maintains continual contact with the goby’s tail, which the goby will flick several times if a predator approaches. They share the burrow at night.