Glossary of Common Terms

adsorption - The concentration of gases, dissolved materials, or ions on the surfaces of solid particles.

alkalinity - The acid combining capacity of a (carbonate) solution, expressed in Milliequivallents (titrate 100ml of water with 0.02 N HCI to the methal orange

allochthonous - Arising in another biotope (Gr. alIos - other; chthon -land).

anaerobe - Organisms which either obligately or facultatively live in the absence of oxygen (Gr. an - without; aer - air; bios -life).

Aufwuchs - A German term referring to all attached organisms, except macrophytes.

autochthonous - Arising in the biotope under consideration (Gr. chthon - land).

autotrophic - Plants that are able to construct organic matter from inorganic molecules or elements (autos - self; trophein - to nourish).

benthal- The region on the bottom of lakes, streams or the ocean (Gr. benthos - depth).

benthos - The organisms associated with the benthal zone or benthic zone.

biocoenose - A community of organisms whose composition and aspect is determined by the properties of the environment and by the relations of the organisms to each"

biotope - A place of life; the totality of the environmental conditions under which a biocoenose exists.

chemosynthesis - The synthesis of organic matter from inorganic matter with the aid of chemical energy rather than light (as in photosynthesis).

consumers - Organisms that nourish themselves on organic matter.

denitrification - Reduction from nitrate to nitrite and further to elemental nitrogen.

dystrophic - Brown-waters having a very high humus content, also often characterized by a low nutrient concentration.

epiphytes - Plants use other plants as a substrate without rooting into them and without withdrawing nutrients from them.

epilithic - plants attached to inorganic substates.

eurytopic - organisms that have a wide range of tolerance to an environmental variable such as temperature (eurythermal). ,

eutrophic - Waters with a large supply of nutrients and hence a rich organic production
(Gr. eu - well; trophein - to nourish).

heterotrophic - The nutrition of plants and animals dependant on organic matter for food (Gr. heteros - other; trophein - to nourish).

laminar flow - The organized unidirectional movement of a liquid or gas.

lentic - referring to lake habitats.

lotic - referring to running water habitats.

macrophytes - Large plants.

nekton - The powerful swimmers among the freshwater animals that are to a large degree

oligotrophic - Waters with a smal supply of nutrients and hence a small organic
production.

periphyton - algae attached to the stream or river bottom. May also refer to algae attached to large substartes, such as large organic matter.

phytobenthos - plants of the benthic zone, typically referring to periphyton

potamon - large stream and river habitats.

potamoplankton - The "true" plankton of large rivers which form their own community
independant from benthic or floodplain sources.

psammon - The community residing in the interstices of sand.

rheokrene - A flowing spring (Gr. rhein - to flow; krene - spring).

rhitron - very small stream or brook habitats.

seston - All the particulate matter suspended in water (Gr. sestos - strainable).

tectonic - Being of origin through movement of the earth's crust.

zoobenthos - animals of the benthic zone; (macrozoobenthos - large animals usually referring to large aquatic invertebrates).