Ecology Flashcards
Habitat Definition
The place where an organism lives
Population
All the organisms of a particular species living in a certain area
Community definition
All organisms of all species in a particular area at a particular time.
Found in an ecosystem
Ecosystem definition
All the organisms and their environment interacting together in a certain area
A self - supporting system of organisms
Biodiversity and affecting factors
The amount of variation shown by species in an ecosystem
Two Measurements:
the number of different species - species richness
the relative abundance of each species - ‘evenness’ of numbers across the species
e.g higher relative abundance = higher biodiversity
Biodiversity affects on ecosystem
Ecosystems with high biodiversity are often more stable.
This is due to ecosytem’s dominated by few species are more likely to be affected by ecological disasters
Biotic Factors definition
Parts of the environment which are living that affect organisms.
They are biological
Biotic Factors
- availability of food and competition for food resources
- predation
- parasitism
- disease
- presence of pollinating insects
- availability of nest sites
- food supply (main affecting factor in river ecosystem)
Abiotic Factors definition
Parts of the environment that are non-living affect organisms.
They are physical and chemical factors
Abiotic Factors
- climate eg light intensity, temperature, water availability
- hours of daylight
- soil conditions eg clay content, nitrate level, water availability
- pollution
- other factors specific to a particular habitat
eg salinity (salt content) in an estuary, flow rate in a river, oxygen concentration in a lake
Trophic Level Definition
a stage or level in a food chain
Herbivore
Carnivore
Omnivore
Herbivore - Animals that only eat plants
Carnivore - Animals that only eat animals
Omnivore - Animals that eat both animals and plants
Producer definition
A plant which uses sunlight to make food
The first member of a food chain/food web
Primary Consumer Definition
an animal that only eats producers
Secondary Consumers definition
an animal that eats primary consumers
Tertiary Consumer definition
an animal that eats secondary consumers
Top Carnivore definition
an animal which is not eaten by anything else
Decomposer definition
organisms such as bacteria and fungi that break down dead, decaying matter
Consumer definition
An organism which eats another living organism
Predator Definition
any ANIMAL which hunts and eats another animal
Prey definition
any ANIMAL which gets eaten by another animal
Ecological Pyramids
Two Types: Pyramids of Numbers, Pyramids of Biomass
Pyramids of Numbers
Represents the number of organisms in each trophic level in a food chain
Shows population of each organism at each trophic level of a food chain
Producers are at the bottom and bars get smaller the further up you go.
P.S if a producer is one tree/large plant, the size of the bar is very small - its only one tree
Pyramids of Biomass
Represents the total mass of the organisms in each trophic level, irrespective of their numbers
- show the relative dry mass of material at each level.
- There is less biomass as you move up the trophic levels
Key: the biomass of an organism in the level above will always be higher, as not all organisms can be consumed and converted into biomass
