Environmental Engineering Reference
In-Depth Information
in river floodplains and on raised riverbanks. Tertiary atmospheric habitats
originate by an input of a surplus of metals in a non-metal-enriched environ-
ment by industrial emissions (Baumbach et al.
2007
) often far way from primary
sites supporting metallophyte populations. They are often strongly influenced
by acidification (by co-emission of sulphur oxides) whose effects are stronger
than those of metals in soil. Species occurring at such sites have been selected
from the local non-metal-enriched environment. These sites are frequently
species-poor, e.g., monocultures of those grass species which have the ability
to rapidly evolve metal tolerances such as: Agrostis stolonifera at the copper
refinery at Prescot, England (Wu et al.
1975
); A. capillaris at the Cd/Zn smelter
at Budel, the Netherlands (Dueck et al.
1984
); and Agropyron repens at the copper
smelter at Legnica, Poland (Brej
1998
). Sometimes metallophytes have arrived
at smelter sites with the ores: an example is the moss Scopelophila cataractae
in Wales and in the Netherlands (Corley & Perry
1985
; Sotiaux et al.
1987
).
An unintentional introduction of Armeria maritima subsp. halleri into the Littfeld
area (Germany) may have been caused by mine workers when moving from
the Harz area to new mining sites (Ernst
1974
). Such 'transport endemism'
(Antonovics et al.
1971
) has probably been a major reason for the extended local
distribution of metallophytes, such as Thlaspi caerulescens and Minuartia verna
in the Pennine orefield, UK. Frequent visits by botanists may be the reason
for the import of T. caerulescens to the Overpelt Zn/Cd smelter site in Belgium
and to its extended distribution in the Peak District, UK. Revegetation of
tailings with poplar trees in the Auby smelter area in France was not successful;
therefore, in the 1920s and in the 1950s Arabidopsis halleri and Armeria maritima
subsp. halleri were introduced from Central European calaminarian grassland
(Dahmani-Muller et al.
2000
), and still show a good performance on the metal-
contaminated soils around the Auby smelter (Bert et al.
2000
).
Tertiary alluvial habitats are more of a natural kind and are generally
species-rich, because they originate as a result of metal loadings to well-
developed soils in riverine systems, often close to primary and early secondary
been flooded with metal-enriched materials and seeds of metallophytes
since the Middle Ages in the Tyne valley, England (Macklin & Smith
1990
),
in the Innerste and Oker valley in Germany (Libbert
1930
; Ernst
1974
; Ernst
et al.
2004
) and in the Geul valley in the Netherlands (Kurris & Pagnier
1925
).
Due to leaching of heavy metals from the surface soils, the survival
of this alluvial heavy-metal vegetation type depends on irregular metal rep-
lenishment by incidental riverbank flooding, such as in the Tyne valley
in 1986 (Rodwell et al.
2007
), and in the Innerste and Oker Valley in 1969
(Ernst
1974
) and 2007 (Klein & Niemann
2007
). These heavy-metal-enriched
sediments not only affect agricultural crops in other parts of the riverbank
lands (Von Hodenberg & Finck
1975
), but also transfer propagules from
