Environmental Engineering Reference
In-Depth Information
Abiotic change
Structural change
Biotic change
Biotic feedback
Engineer
FIGURE 11.3
Cause-and-effect relationships representing a physically engineered ecosystem. The
solid arrow for autogenic engineering is the physical manifestation of organismal structure inserted into
the abiotic milieu. The dashed arrow for allogenic engineering represents the action of the engineer on
other living or nonliving structures. (From
Jones et al. 2010
.)
their food), and structural change (e.g.,
conspecific living space) may feed back
to the engineer.
The degree to which structural changes
alter abiotic resources and conditions via
interactions of structure, kinetic energy,
and materials.
The magnitude of control by engineers
depends on:
The sensitivity of other species and
ecological process to the structural and
abiotic changes.
The degree and type of structural
change(s) they cause, which is a
function of engineer density and
per capita engineering activity (e.g., the
number of dams per beaver, the amount
of wind attenuation per tree).
These variables are fundamentally differ-
ent from those determining the degree of
trophic control.
Extending the physics of organisms to
ecosystems, along with the evolutionary
ram ica ionsofthiskindoforganism-
environment coupling, is an active area
in basic and applied research. Within the
realm of policy and management, we need
to understand the impacts of human eco-
system engineering to fully grasp our influ-
ence on ecosystem functioning.
The persistence of these changes amidst
physical and biological decay, which is a
function of engineer maintenance (e.g.,
dam repair, tree growth and survival),
intrinsic material durability (e.g., wood,
mud), and destructive forces (e.g., floods,
wind throw).
