Term
|
Definition
| all the communities/living organisms/ biotic factors and environmental / abiotic factors in a particular area; these factors are interacting and interdependent; they make up a self-contained system which is self supporting in terms of energy flow. |
|
|
Term
|
Definition
| all the factors in a habitat which affect an organism; these may be either living (= biotic) or non living (= abiotic). |
|
|
Term
|
Definition
| all the members of one species in a habitat at one time. |
|
|
Term
|
Definition
| all the organisms (= ? the biotic factors) in a particular habitat at one time. |
|
|
Term
|
Definition
| the geographical area occupied by an ecosystem. |
|
|
Term
|
Definition
| the role of a species within an ecosystem; its location/spatial habitat and functions - relationships/interactions with other organisms - and its effect on the environment. Two different species do not normally occupy exactly the same niche in the same habitat at the same time (= ‘competitive exclusion principle’). |
|
|
Term
|
Definition
| a group of potentially interbreeding individuals; which do not normally interbreed with other groups/species to produce viable, fertile offspring. |
|
|
Term
|
Definition
| a sequence of organisms in an ecosystem in which each is the food of the next organism in the sequence. Arrows represent energy flow through the chain. |
|
|
Term
|
Definition
| all the interconnected food chains in an ecosystem (usually complex to calculate). |
|
|
Term
|
Definition
| a feeding level in a food web - defined by the method of obtaining food; all the organisms in a particular trophic level are the same number of energy transfers away from the producers. |
|
|
Term
|
Definition
| the first organism in a food chain; an autotroph (i.e capable of manufacturing organic molecules/food, normally by photosynthesis (thus, normally a plant). |
|
|
Term
|
Definition
| the second organism in a food chain (in the second trophic level); consumes/obtains energy from the producer; (thus a herbivore). |
|
|
Term
|
Definition
| consumes/obtains energy from the primary consumer; (thus a carnivore). |
|
|
Term
|
Definition
| a representation of the number of organisms in each trophic level in an ecosystem; the width of each block is proportional to the number of organisms in each trophic level. |
|
|
Term
|
Definition
| (better) a representation of the biomass in each trophic level in an ecosystem; the width of each block is proportional to the biomass in each trophic level. |
|
|
Term
|
Definition
| (better still) a representation of the energy in each trophic level in an ecosystem; the width of each block in proportional to the energy in each trophic level; usually measured in KJ m.-2 year-1. |
|
|
Term
|
Definition
| the maximum population that a particular environment can support. |
|
|
Term
|
Definition
| the environmental factors which reduce population growth rate: e.g. disease, predation, competition. |
|
|
