Geoscience Reference
In-Depth Information
Indirect effects of other
human activity on viability
of resource X
Climate/natural hazard
effects on resource X
Human extraction of
resource X
Characteristics of resource
X other than those
influencing its availability to
humans
Availability of resource X
for human extraction
Other organisms connected
to resource X through
ecological relations
Ecological community
parameters
Figure 12.2
Land-use ecology: resource extraction in isolation or in relation.
parts the use of very simple conceptual models of land-use ecology ranging from
'stock depletion' to 'tipping bucket' models. The 'stock depletion' model treats
ecological response as linearly-related to human resource use. Ecological relations
are a depletable stock - an expansion of population, cash cropping, timber extrac-
tion by multinationals . . . etc. will necessarily lead to commensurate levels of envi-
ronmental transformation. Dependence on this model is often implicit - political
ecological analyses whose 'chains of explanation' trace changes only to the point
of documenting 'greater pressures on the environment' rely on this model. Without
clearly stated caveats, references to 'greater pressures on the environment' are
viewed as instances of 'environmental change' by most audiences. Somewhat more
sophisticated treatments incorporate a threshold concept, above which increases in
human pressures will have a disproportionate impact on the environment (the
bucket tips).
Political ecology, while making quite different claims about the social roots of
environmental change, shares with some of the social scientifi c approaches that it
critiques (neo-Malthusianism, hazards theory, IPAT model, environmental security
. . . etc.), conceptual models of ecological response to human activities. In this way
much political ecology work has reinforced the dominant views that: (i) the resource
is isolated from the broader web of ecological relations; and (ii) ecological response
is proportional to the magnitude of resource extraction. As shown in fi gure 12.2, a
singular focus on how resource extraction infl uences the availability of the resource
may ignore other factors affecting the resource's availability; features of the resource
which do not affect its availability to human society; and broader effects of resource
extraction on other organisms and ecological community parameters. Cases when
the resource is strongly tied to other organisms and processes, more fuller engage-
ments with ecological relations may be necessary to truly understand the environ-
mental effects of resource extraction. Even if the extracted resource is the sole
concern of the researcher, it's availability may be determined just as if not more by
climate or indirect effects of human activities (via the dynamics of other organisms
and physical processes) than by the primary extraction activity itself. Moreover, the
direct effects on resource
X
may be small compared to the indirect effects of resource
X
extraction on other populations, processes or community parameters. For example,
