5.1 - What is an ecosystem? Flashcards
define niche
specific role of an organism in its ecosystem
(both biotic & abiotic interactions)
what are 3 types of adaptations?
- physiological
- anatomical
- behavioural
What is an ecosystem?
the interaction of the living organisms in a community with the non-living environment
What is a community?
the populations of organisms in a habitat or ecosystem
What is a habitat?
place with a distinct set of conditions, where an organism lives
What is a population?
a group of interbreeding individuals of the same species found in an area
Which 2 factors control the distribution of organisms in a habitat?
- biotic
- abiotic
Which keyword explains why species compete with each other?
they have the same niche
Why may the distribution of organisms be affected if 2 species have the same niche?
they will compete, and eventually one species will outcompete the other and exclude that species from the habitat
What determines which species live in a habitat?
- Adapted to survive & reproduce there
- Dependent on which species wins the competition (of mates, territory, food etc)
What are 3 examples of abiotic factors?
- oxygen concentration
- soil factors
- climate
What are 3 examples of biotic factors?
- competition
- predation
- disease
What is distribution?
the spread of an organism lives
What are anthropogenic factors?
factors caused by human activity
What are the 2 pieces of equipment that you need to measure species abundance?
- transect
- sampling
What must you always remember when using a quadrat?
- cover total area with quadrats
- identify all species present in the area
- count the number of these species
How do calculate species cover?
total % cover in all quadrats/ number of quadrats
How do you calculate percentage frequency?
(number of quadrats you found species in/total number of quadrats) x 100
What is meant by succession?
the progressive change in the composition of diverity of the species in a community in one place over period of time
Using a point quadrat, how do you calculate percentage cover?
(number of needles that hit species/total number of needles) x 100
What are the 2 types of transect?
- belt transect
- interrupted transect
What apparatus could use to measure angle of slope?
clinometer
What apparatus could use to measure oxygen concentration?
oxygen probes
What equipment could be used to measure pH?
universal indicator or pH meter
What is are pioneer plants?
the first species to colonise bare ground
What is primary succession?
occurs when the starting group is bare with no living things present
What is secondary succession?
occurs on bare soil, where an existing community has been cleared
What is a climax community?
all the species that in the stable finale ecosystem, after succession has taken place
Why is it difficult for species to colonise the sand? (3 reasons)
- high salt concentration
- free draining soil
- soil has low nutrient status
What is the start of a sand dune called?
an embyro dune
What is the first phase of primary succession called?
colonisation (pioneer phase)
What are the two species of plant that live on embryo dunes?
sea holly and sea rocket
What are the 2 characteristics that pioneer plants need to survive on embyro dunes?
- xerophytic
- halophytic
what does xerophytic mean?
dry loving
what does halophytic mean?
salt loving
What is meant by ‘succession’?
the progressive change in the composition & diversity of a community in one habitat over a period of time
What is deflected succession?
how the makeup of the climax community depends on the climate & soil conditions
What is a plagioclimax community?
type of community reached when interference by humans occurs
What happens in the pioneer phase of succession?
- pioneer plants break up rock surface, allowing organic material to build up within the broken rock
- this forms soil
- the pioneers change the conditions in the habitat to make them suitable for other species
What is the role of the pioneer species?
the pioneers change the conditions in the habitat to make them suitable for other species
Which species moves into the habitat (embyro dunes) after the pioneer species?
couch grass
What is the role of the couch grass in the habitat?
- stabilise the soil & absorb all available water
In which 2 ways does the quality of the substrate improve as move back through the dunes?
- nutrient levels increase
- water retention improves
After the substrate quality improves, why does a skeletal soil form? (3 points)
- decay of plant material
- death & decay of animals
- decay of seaweed
What type of dunes comes after embyro dunes?
yellow/building dunes
What type of dunes comes after yellow dunes?
fixed/grey dunes
What comes after fixed dunes in the succession of sand dunes ?
grassland
What comes after grassland in the succession of sand dunes?
scrubs
What is the stage of succession reached after scrubs?
climax community
What is the main reason that causes secondary succession to occur?
habitat destruction, as the result of natural disasters
what is the pioneer species on yellow dune?
marram grass
How is marram grass well adapted as a pioneer species?
- blade-shaped leaves which roll inwards in dry conditions
stomata are on the inward-rolling surface, so water loss by transpiration is reduced - large roots allows dune developments
- shoots develop along it stem, to ensure that it is never covered w sand
