Topic 10 Flashcards
(56 cards)
What’s an ecosystem
life supporting environment , includes all the organisms living in a particular area known as a community ,
Ecosystems can vary in size
What’s the biosphere
What’s a biome
The biosphere is all the areas of earths surface where living things survive
The biosphere is the largest ecosystem
a biosphere is split into biomes
What succession (there are 5 stages)
process by which communities of
animals and plants colonise an area and then
over time are replaced by more
varied communities.
What’s primary succession
This type of succession occurs where no life has
previously existed eg bare rock
What’s the first stage which is colonisation
These include algae, mosses and fungi , they penetrate the surface of bare rocks helping it to break into smaller grains
The second stage is pioneer
Decay adds to soil depth , decomposition
The third stage is herbaceous plants
Larger plants can grow due to soil depth and minerals
The forth stage is shrubs and bushes
Once the soil becomes deep enough larger plants can be supported , plant diversity increases
What’s the 5th stage which is climax community
As plant biodiversity increases, so does the diversity of animals that can be supported.
Eventually a climax community is reached where the
biodiversity is constant over time
What’s an artificial climax community
These are climax communities which are constant
and self-sustaining but not formed naturally
Lichens are organisms composed of a fungus and algae living together. Lichens colonise bare rock.
Explain how colonisation of bare rock by lichens can result in succession over long periods of time.
lichens are pioneer species (1)
• they break down surface of rocks to create soil (1)
• therefore other plants are able to {grow / be established) (1)
• death and decay helps to {create humus / recycle
minerals) (1)
• therefore providing niches for either plants or animals (1)
What are abiotic factors
Non-living elements of the habitat of an
organism.
Example: light, temperature, wind and
water availability, oxygen
availability, soil structure.
What are biotic factors
Living factors Plants
• Algae
• Fungi
• Herbivores
• Predators
Pathogens
How would abiotic factors effect a community : light intensity , enzymes , wind and water currents , o2 availability , ephadic factors
L - needed for photosynthesis, if there a low lvls plants must be adapted to low light lvls
T - effects enzyme controlled reactions in plants
W - water loss
O- need o2 to survive
E - relates to structure of soil. Sandy soil leaches minerals as water passes thru and drains quick , clay gets waterlogged and js difficult to drain
What are the effects of Biotic factors - predation
As prey pop incr more food for
the predators so predator population
grows too.
What are some density dependent factors
Biotic factors that effect a population
eg Predation , food source , space and competition , parasitism, Impact of the factor depends on
Impact of factor depends on how many organisms there are
in an area.
E.g. disease and parasitism.
The more individuals in an area
the more likely the disease is to
be transmitted between
individuals.
What are some density independent factors
Abiotic factors that Effect the pop regardless of its size / density
E.g. extremes of
temperature have the same
effect on all individuals
regardless of how many
individuals there are.
Climate weather natural disasters
What’s abundance
What’s distribution
The relative representation of species in a particular ecosystem compared to other organisms in the same habitat
Where are these specifies found and how they’re arranged (random, uniform or clumped)
What are limitations to quadratting
What 2 ways can quadrats be used
- It needs to be on flat land , the quad rates need to be spread randomly
- Random sampling (used to measure abundance of species, must be placed randomly to avoid bias, no abiotic factor monitored)
- Systematic sampling (measures the change in distribution of a species over a distance, measure change in abiotic factors , quadrats placed along tape at regular distances)
There are two types of competition between organisms;
; interspecific competition between individuals of different species and intraspecific competition between individuals of the same species.
What are limitations to the acfor scale
The limitations of this scale are:
1. It is subjective – 2 people would probably never come up
with the exact same scores, may classify same species differently
What’s a permanent quadrat
Left in place all of the
time. This means data
can be collected reliably
from the same place
through the seasons
2 types systematic sampling (not random)
- Line transects – A tape is stretched between two
points and every individual plant (or animal) that
touches the tape is recorded. - Belt transects – Two tapes are laid out and the ground
between them are sampled. Quadrats could be laid
out along a tape to form a belt transect.
Trophic lvls
Producers
Primary consumers
Secondary consumers
Tertiary consumers
Decomposers
Producers - make food
Primary - eat producers
Secondary - feed on herbivores (primary consumers)
Tertiary - feed om carnivores
Decomposes - final trophic lvl
