Lecture 01 Concepts and Vocabulary
Concepts
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Stream order (Strahler), hierarchies, and nesting. The US Hydrologic Unit Cataloging (HUC) system.
Longitudinal profiles: erosion, transport, and deposition
Rivers drain watersheds
Food webs (and trophic levels)
Why do some species appear in some places and others not? (Landscape filters)
Streams are not Teflon pipes! (Nutrient processing)
“The River Continuum Concept” (A “have to know”)
Functional feeding groups of organisms (benthic macroinvertebrates, but also microbes, fish, etc.)
Human needs (ecosystem “services”) vs River needs (ecosystem “rights”)
Vocabulary (Note: Word origins can sometimes be very helpful. Look them up.)
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Allochthonous and Autochthonous: Both derived from Greek words related to “earth” and borrowed
from the field of Geology by stream ecologists. Autochthonous rocks are ones derived from the same
place. In stream ecology the sense is applied to biomass (carbon, with other elements) that grows
within the stream (i.e., algae and other plants). Autochthonous rocks (and biomass) come from other
places. For stream ecologists this biomass is typically leaves, twigs, and other natural debris that
washes into streams from terrestrial origins.
Autotroph: Literally “self” + “nourishing”, primary producers, can do photosynthesis. See
Heterotroph.
Detritus: 1795, "process of erosion," from L. detritus "a wearing away," from detri-, stem of detere
"wear away" (see detriment). Geological sense of "matter produced by erosion". In ecology detritus
is biomass that was once alive and is now dead. Potentially this is food for somebody. Whether it is
or not is dependent on a number of factors including the “quality” of the detritus, often judged by its
stoichiometry (balance of C:N:P).
Fluvial: "pertaining to a river," late 14c., from L. fluvialis "of a river
Heterotroph: Literally “other” or “various” + “nourishing, derives nourishment by eating the
production of other organisms, either autotrophs or other heterotrophs.
Morphology (features): pools, riffles, runs, plane bed, cascades, step-pools, falls
Reach: A representative section of a stream or river. At a fine (feature) scale streams seem
heterogeneous. But at a slightly larger scale there appear to be repeating units. At larger scales the
nature of the stream changes over the longitudinal profile.
Riparian: "of or pertaining to river banks," 1849, from L. riparius "of a river bank," from riparia
"shore," later used in ref. to the stream flowing between the banks, from ripa "(steep) bank of a river,
shore,"
Useful on-line sources (These are okay to use!)
One-Look Dictionary Search: http://onelook.com/
On-line Etymology Dictionary: http://www.etymonline.com/index.php