7923

• UCREFRP Catalog Number: 7923
• Author: Carter, J. G. and V. A. Lamarra.
• Title: An Ecosystem Approach To Environmental Management, Chapter 17.
• USFW Year: n.d.
• USFW - Doc Type: 261-287
• Copyright Material: YES

~ INPUTS (PHYSICAL, CHEMICAL. ORGANICS)

r---- ------ - - -- - - - -- --...,

I PRIMARY PRODUCE.RS 1
I ALGAE I

, ST~~URE DIVERSITY II
l GUILDS RICHNESS
I BIOMASS EVENNESS I

FUNCTION ~ I
I PRODUCTION CONSUMERS
I RESPIRATION ~:~~~~~~~E~ 1
I 1 ST~~~RE DIVERSITY I

t GUILDS RICHNESS I
I BIOMASS EVENNESS ,

l FUNCTION I
I DECOMPOSERS / :;~~~~~~~N l
I BACTERIA AND FUNGI CPOM PROCESSING I

I STRUCTURE I
I =M I
1 ACTIVITY I
I FUNCTION I
I PRODUCTION I
I ~S~~~~~~~ I
I FPOH PROCESSING I
I I

L____________________J

5Y STEM 'BOUNDARY

~ OUTPUTS (PHYSICAL. CHEMICAL. ORGANICS)

Figure 3. Major components and interactions
of the aquatic ecosystem.

fates: (1) it is consumed by animals or (2) it enters the
decomposer cycle as dead plant material.

Within the animal or consumer component, plant
material is used for growth and reproduction. Growth is
termed secondary or tertiary production depending upon
whether the animal is an herbivore (secondary producer) or
a carnivore (tertiary producer). The animals ultimately
die and enter the decomposer cycle.

Within the decomposer component all dead plants and
animals are ultimately processed by invertebrates, fungi
and bacteria. These organisms through mechanical or
metabolic (chemical) activities break the large organic
molecules into smaller inorganic and organic molecules
which can be used by the primary producers.

Within each component there are structural and
functional parameters which affect the way energy flows
through the ecosystem. These parameters are defined at a
point in time and therefore are instantaneous values, that
is, they are mere snapshots of a continually changing

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