Mine Closure - Mining and the Environment: From Ore to Metal - page 823

FIGURE 21.5
Surface of Tailings Storage, Showing
Regrowth of Acacia sp. Following a
Wild-fi re, Tennant Creek Area, N.T.,
Australia

Sustainability

Rehabilitation of natural vegetation requires that the resulting vegetation community is
self-sustaining. This depends on many factors, including the following:
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The total assemblage of species including micro-organisms, and fauna;

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The ability of species to survive, at least to i rst reproduction, under the prevailing
conditions;

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The ability of seed to germinate under the prevailing conditions;

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Genetic diversity within each species;

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Absence of invasive weeds and serious pathogens;

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Resilience to disturbance - the ability of the vegetation community to recover follow-
ing natural or man-made perturbations such as l ooding or i re ( Figure 21.5) , and

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Recycling of nutrients.

Nutrients may be absent or at very low levels, requiring at least an initial input of essential
nutrients at the commencement of rehabilitation, particularly if mulch has been applied.
The sustainability of agricultural or production forestry communities depends on many
of the same factors. However, the substantial harvesting of biomass means that nutrient
recycling is relatively limited, so that on-going additions of fertilizer are required. In other
words, these artii cial systems are sustained by repeated human intervention; there is no
requirement that they be self-sustaining.

Acceptance (or Completion) Criteria

Acceptance criteria are the pre-determined conditions to be met to demonstrate that the
overall long-term objective of rehabilitation has been achieved. In the case of natural vegeta-
tion which may take decades to develop, the acceptance criteria are selected to demonstrate