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 ECOLOGY : FIELD TRIP TO CORREZE

Ecology : Introduction
 

Ecology The study of living organisms in the natural environment. How they interact with one another and how the interact with their nonliving environment.
Ecosystem Community + Abiotic environment, interacting
Community All the populations of the different species living and interacting in the same ecosystem.
Species A group of organisms that can breed to produce fully fertile offspring.
Populations A group of organism of the same species which live in the same habitat at the same time where they can freely interbreed.
Biodiversity The total number of different species in an ecosystem and their relative abundance.
Habitat The characteristics of the type environment where an organism normally lives. (e.g. a stony stream, a deciduous temperate woodland, Bavarian beer mats).

Energy and organisms

Autotrophs Organisms which can synthesise their own complex, energy rich, organic molecules from simple inorganic molecules (e.g. green plants synthesis sugars from CO2 and H2O)
Heterotrophs Organisms who must obtain complex, energy rich, organic compounds form the bodies of other organisms (dead or alive).
Detritivores Heterotrophic organisms who ingest dead organic matter. (e.g. earthworms, woodlice, millipedes)
Saprotrophs Heterotrophic organisms who secrete digestive enzymes onto dead organism matter and absorb the digested material. (e.g. fungi, bacteria)

The place of an organism in its environment

Niche = Habitat + role + tolerance limits to all limiting factors

The Biosphere

The part of the planet Earth occupied by living organisms. Where they interact with themselves and the non-living parts of the plant to maintain the biogeochemical cycles (e.g. carbon cycle).

Arguably from 10 km altitude (the limit of the troposphere) to 3 km below sea level (the deepest ocean trench). Bacteria have even been found living in oil deposits several km down in solid rock.

© Paul Billiet 2004