Term | Definition |
Ecosystem | all the living organisms and all the non-living components in a specific habitat, and their interactions |
Habitat | the place where an organism lives |
Population | all the organisms of one species, who live in the same place at the same time, and can breed together |
Community | all the populations of different species who live in the same place at the same time, and can interact with each other |
Producer | an autotrophic organism that converts light energy to chemical energy, which is then supplied to consumers |
Consumer | a living organism that feeds on another living organism |
Decomposer | an organism that feeds on dead organic matter |
Trophic Level | the level at which an organism feeds in a food chain |
Niche | the role that a species plays in an ecosystem |
Productivity | a measure of the rate at which energy passes through each trophic level in a food chain |
Primary Productivity | the rate of production of new biomass by producers; the total energy fixed by photosynthesis and used to synthesise organic molecules |
Net Primary Productivity | gross primary productivity minus the energy lost; the total amount of energy available to primary consumers |
Succession | a directional change in a community of organisms over time |
Sere | an intermediate stage found in ecological succession in an ecosystem advancing towards its climax community |
Conservation | the maintenance of biodiversity, including diversity between species, genetic diversity within species, and maintenance of a variety of habitats and ecosystems; but the area can still be sustainably exploited |
Preservation | protection of species by leaving their habitat completely untouched |
Carrying Capacity | the maximum population size that can be maintained over a period of time in a particular habitat |
Biotic Factors | factors resulting from the living organisms in an ecosystem: food supply, predation and disease |
Abiotic Factors | factors resulting from the non-living components of an ecosystem: pH, temperature and soil type |
Gross Primary Productivity | the rate at which plants convert light energy into chemical energy |
Nitrification | the oxidation of ammonium ions to nitrite ions or nitrate ions by chemoautotrophic bacteria |
Denitrification | the conversion of nitrate ions back to nitrogen gas |
Nitrogen Fixation | the conversion of nitrogen gas to organic nitrogen in the soil (e.g. ammonium ions) |
Limiting Factor | a factor that, when in short supply, limits the rate of a reaction or limits growth |
Competition | the interaction of organisms when resources are not present in adequate amounts to satisfy the needs of all the organisms who depend on those resources |
Coppicing | cutting a tree trunk close to the ground to encourage new growth |
Biodiversity | the variety and variability of life; within species, between species and between ecosystems |