Environmental Engineering Reference
In-Depth Information
Remediation and land reclamation of metalliferous mining sites is often in
direct conflict with conservation efforts ( Johnson
1978
). In Natura 2000,
calaminarian grasslands are considered as Special Areas of Conservation under
the Code 6130.
Regulatory drivers seem strongly biased to classify sites as either 'clean' or
'polluted'. Instead of considering metallophyte habitats 'polluted', which
implies negative value and determines ontological consequences (namely
rehabilitation to clean background conditions), sites could be considered as
'metal-enriched'. Metallophyte habitats present metal-enriched islands in a sea
of background concentrations of metals. Landscape heterogeneity with envir-
onmental gradients, even in what is considered a pollution scenario, drives
biological diversity. The intrinsic quality of metal-enriched sites enables the
development of endemic metallophyte communities. Many sites have been
destroyed on the assumption that chemically and physically hostile environ-
ments are biologically insignificant ( Johnson
1978
).
Habitats of metallophytes are in conflict with common existing perceptions
of naturalness. The influence of humans in pristine undisturbed habitats is
generally considered negative in ecocentric nature visions (Keulartz
2005
).
Restoration ecology is tailored to deal with these alterations (i.e., mining
demands) of the environment to the original natural situation. Anthropocen-
tric nature visions, on the other hand, consider metallophyte habitats as indus-
trial wasteland. Metaphors like 'ecosystem health' subscribe rehabilitation to
chemically, physically and ecologically degraded systems. It is generally antici-
pated in nature policy that strongly modified environments do not possess
significant natural and biodiversity values (Lenders et al.
1997
).
In former decades and centuries metallophyte habitats are considered at
best valueless (and ignored), causing environmental problems and were seen
as an industrial blemish on the landscape. Many sites have been efficiently
eliminated from the landscape in the last decades (Smith
1979
). Due to
changed awareness, they are currently protected in Europe by the Habitat
Directive. Most mined areas have a long history of mining and the evidence
is the remains of the former mining industry that shaped the landscape. These
relicts (including metallophyte communities) are part of the heritage value of
a specific area. Eliminating these elements from the landscape, even if they
are considered scars, cleans a landscape of its past. Today most landscapes are
now heavily human influenced, and the discrepancy in policy between natural
and anthropogenic genesis of a site is virtually non-existent in the ecology
of metallophyte communities. Moreover, history can add to natural values.
Besides land reclamation and remediation, metallophyte communities face
the same fate as most other nutrient-poor communities such as chalk grass-
lands in the last century which depended on extensive traditional agriculture.
European metallophyte communities have experienced a large-scale decline
