Authors: Fey, MV; Mills, AJ


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Fey, MV & Mills, AJ 2009, 'Environmental envelopes — identifying limits affecting ecosystem management after mining', in AB Fourie & M Tibbett (eds), Mine Closure 2009: Proceedings of the Fourth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 33-40,

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Environmental envelopes are so named because they depict how parameters of interest are shaped by their environment. They are boundary lines separating the observed world from an imaginary one. Quantile regression enables us to determine their position objectively. Once located, the envelope enables us to separate the range(s) of a determinant variable over which some variable of interest (relating to biological performance, for example) is inevitably minimal from the range over which it is potentially at its maximum value. Thus, in ecosystem management, which is critical to the sustainability of land use after mine closure, we can identify ways in which plant cover and species diversity are affected by environmental variables such as soil infiltrability even under conditions when other determinants are not kept constant. Recognising this paradigm allows restoration ecologists to reduce their dependence on factorial field experiments for discovering suitable methods of mine site rehabilitation. It is also applicable to discovering relationships between abiotic variables in large data sets, such as that between routinely measured soil properties and ones which are not readily determined but of which knowledge is critical in determining appropriate restoration practices after mining. If combined with the diagnosis and recommendation integrated system (DRIS) principles and enough spade work to build a reliable and comprehensive database, it could revolutionise management by generating norms in terms of which the factors affecting ecosystem function can be ranked in order of limiting importance.

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