Environmental Engineering Reference
In-Depth Information
ecosystems; the health of the planet; the breakdown of systems). This particular
theory of ecology has become an attractive metaphor enabling transdisciplinary
dialogue, and perhaps has encouraged a proliferation of medical metaphors in
environmental management.
Through tracing the biography of an idea, and in paying attention to the history
and geography of resilience, it is possible to find geographical origins even in global
concepts circulating through the Anthropocene literature. Ecology began with
specific local ecosystems. Historically, the closed, finite ecosystems of North
American freshwater lakes and their fisheries were carefully documented. In the
late nineteenth century, Stephen Forbes, later President of the Ecological Society
of America, spoke of the freshwater lakes as 'microcosms' for study. His Illinois
lake was a 'little world within itself, a microcosm within which all the elemental
forces are at work and the play of life goes on in full, but on so small a scale as to
bring it easily within the mental grasp' (Forbes, [1887] 1925: 537; Golley, 1993:
36-37; Schneider, 2000). The relationship between elements was relatively simple
and could be described by linear relationships because the lake was 'climatically
buffered, fairly homogenous and self-contained' (Holling, 1973: 18). But the
rapidly changing world of the latter half of the twentieth century, where cities were
growing, land-clearance rates were high and pollution was changing the way the
natural world worked, demanded new models. Even the heterogeneous (patchy)
landscapes of the arid rangelands in the western United States and Australia did not
function as closed systems. They were prey to invasive species, and consequent
hydrological change, and different parts of the landscape responded differently as
land use changed. The idea of assessing the ecosystems as if they were stable made
little sense. The resilience framework suggested a different management strategy,
which de-emphasised the predictable world, and favoured keeping options open
'to absorb and accommodate future events in whatever unexpected form they took'
(ibid.: 21). It was a model that recognised that change, not stability, was defining
ecosystems.
Science from somewhere
Science traditionally aspires to universal truths, that is, concepts that apply
whenever the preconditions specified are met. Yet the science of ecology has
developed as a very specific science of place. Since Alexander von Humboldt's
nineteenth-century travels in search of climatic parallels, biogeographies of climatic
and latitudinal similarity have invited comparison. Even so, ecological systems
remain dependent on edaphic (soil or geological) conditions, on temperature and
elevation, on 'edge effects' and increasingly on encroachments from human society,
including massive shifts of biota from continent to continent. In short, there is a
veritable suite of preconditions making it difficult to transfer ecological knowledge
of one place to another without the interpretation of a locally expert ecologist.
Raymond Specht, the ecologist who co-ordinated Australia's national contributions
to the International Biosphere Program (IBP) in the 1970s, commented that
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