FLOOD00235

• County: Statewide
• Community: State of Colorado
• Stream Name: All
• Title: Stream, Riparian, and Wetland Ecology - Class material, Volume 1 of 2
• Date: 9/1/1987
• Prepared For: Students
• Prepared By: Professor Windell
• Floodplain - Doc Type: Educational/Technical/Reference Information

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CHA.'rnEL WIDTH

. p . Prl~ry Production; R . Ecosystem Respiration

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Organic FIR- Heterotrophic
Matter ~AT" .,
Input. Autotrophic
{Allochthono\lll)
INPt.'TS
C1'OM FPOM
IUgh 1.0>.
<1 Hetecrot'fophlc
Lov MiUh
(Reduc-
.d)
>1 Autotrophic
--
Low H:lgh
<1 I lie tertrophlc
I --

Prl~ry
Production

INPti'S

Low

(Algae aod
Mosus)

Periphyton

Bigh

{Algae and
Hydroph:nes}

Perlphyton

~ Low
r-"
, _ (Primarilv
Planktonic)

Figure 3. Comparhon of the biological habitat of small, medlU1:1 and large sereaa aCCI~rdln& to
the River Continuum Concept.

being cooler in the summer months, warmer in the wint.er months and having
lower seasonal and diurnal temperature variation.

Streams with closed riparian canopies characteristically receive
significant amounts of coarse particulate organic mat.ter (CPOM) in the form
of leaves. needles, flowers, twigs, and branches. In many st reams, the
major influx of CPOM occurs during the annual autumn leaf fall. The ratio
of gross primary production (p) to community respiration (R) is normally
less than one over most of the annual cycle indicating that headwater
ecosystems are strongly heterotrophic. ThUll t.he maj or portion of the
trophic resource is imported from the adjac.mt ecosystem in the form of
CPOM during the fall.

Medium-Size Streams

Medium-size streams in the range of fourth to sixth order are
distinguished from small headwater streams and large streams by a number of
easily observable characteristics (Figure 2)" As small tributaries uni te,
channels progressively increase in size becoming wider and deeper. The
gradient or slope is generally less than headwater reaches. Volum" of
water flow increases significantly with the Increased tributary input. The
dominant substrate type is related to watershed geology, but
characteristically ranges from coarse to fine particles represented by