Environmental Engineering Reference
In-Depth Information
due to modern intensive agriculture and its application of fertilisers and lime.
Some specific examples can be cited.
Currently, the large landscape characteristic spoils heaps of the Mansfeld
area in Germany face complete destruction of the metallophyte habitat.
Tailings continue to be removed for use as road construction materials. With
the increasing prices for copper, these historic spoil heaps are scheduled
for reworking. At other sites, spoil heaps dating back to the Middle Ages and
today lying amidst agricultural fields (Schubert
1953
; Ernst
1974
) have been
removed, but the soil underneath the spoil heaps, often related to copper
shales, is still so highly metal-enriched that the agricultural crops (wheat, sugar
beet) are very chlorotic and yield poorly. In the Harz Mountains, the materials
from many tailings areas were used for highway construction, still visible by
the metallophytes on the verges of the Gottingen-Kassel highway (Germany).
Secondary sites in the Stolberg and Eschweiler area in Germany were used as
landfills for waste, and have subsequently disappeared. Another tailings site
was revegetated, but unfortunately used as a children's playground, resulting
in symptoms of Cd and Pb toxicity in those children consuming leaves of
Rumex acetosa, a plant species with a high accumulation capacity (MAGS
1975
).
The locus classicus for the Violetum calaminariae, the Breiniger Berg near Aachen
is now partly overgrown by Pinus sylvestris trees.
In the UK Peak District, over 75% of all remnants of the lead mining industry
(especially rakes and surface works with metallophyte communities) have
disappeared, mainly due to agricultural improvement of pasture in the last
two centuries (Barnatt & Penny
2004
).
Plombi`res in Belgium was a 30 ha ancient secondary site well-known for its
assemblage of rare species (Simon
1978
). Only 5 ha remain today after a large-
scale remediation project involving surface capping with 'clean' soil in 1996.
Casino Weiher Halde at Kelmis, also in Belgium, is the site of the former
Altenberg mine, worked since Roman times. The site has largely disappeared
due to the building of shopping premises. After construction of houses on the
site in 2007, the last remaining part is now designated as a nature reserve.
Based upon a 1962 mapping and a site visit in 2006, it is estimated that of the
former 5 ha heavy-metal vegetation, only c. 1 ha remains, a loss of around 80%
(Ernst unpublished data).
The once extensive tertiary alluvial metallophyte vegetation along the Geul
River of the Netherlands and Belgium covering over 18 km on both sides of the
border have nearly completely disappeared due to intensive agriculture. Over
99% has disappeared since 1925 and only 0.5 ha now remains (Van de Riet et al.
2005
). The best-developed site was destroyed by the construction of a trailer
park in the late 1970s. At nearby Rabotrath well-developed tertiary metallo-
phyte vegetation could be found up until 2005, when these meadows were also
put under agricultural practice, and have since diminished substantially.
