Vegetation on Contaminated Sites near an Hg Mine and Smelter
323
3
Results and Discussion
3.1
Hg Mine Spoil Heaps
The exploitation of mercury in this region dated since the 18th century (Kodera
1990). In the surroundings of the mine there are small, unreclaimed heaps. The
soils developed several years after dumping and mosaic vegetation cover was
established by colonization from native local plant species.
3.1.1
Characteristics of Soils
The substrate of mine spoil heaps is composed of stones. The spoil heaps have a
graveley texture, so the plants growing there are deficient in water and nutrients
(0.65-2.28% Cox, 0.1-0.19% N). The input of heavy metals from the weathering
spoil material to the soil has been recorded. According to our analyses, the soil
contains high concentrations of metal residues. For example, Hg concentration
ranged from 72.7-4700 mg/kg and Cu from 40.0-11 300 mg/kg. Soil established
on the heaps has an alkaline reaction, with pH ranging from 7.3-8.1.
3.1.2
Contamination of Plants
Notable contamination of aboveground plant parts by mercury, copper and
sulphur was found on study heaps. The aboveground parts of dominant plant
species were analyzed.
Higher amounts of Hg and Cu occurred in Agrostis stolonifera than in Silene
vulgaris. Mercury concentration reached 11.2 mg/kg in the aboveground parts of
Agrostis stolonifera and reached 7-44 mg/kg in Silene vulgaris. Concentrations of
Cu were 87 mg/kg in Agrostis stolon if era and 18.5 mg/kg in Silene vulgaris.
3.1.3
Characteristics of Vegetation
Colonization of spoil heaps by higher plants depends on soil properties such as
weathering, chemical changes and microclimate (Schubert 1954; Ernst 1965). One
of the basic conditions is the ability of plant species to develop metal resistance
(Ernst 1990).
Plants colonies on Hg mine spoil heaps are very patchy. Vegetation cover is a
mosaic, depending on the weathering and development of soils. High percentages
of barren soil occur there. Species such as Agrostis stolonifera, Cardaminopsis
arenosa and Silene vulgaris dominate. Other plants, such as Hypericum
323
3
Results and Discussion
3.1
Hg Mine Spoil Heaps
The exploitation of mercury in this region dated since the 18th century (Kodera
1990). In the surroundings of the mine there are small, unreclaimed heaps. The
soils developed several years after dumping and mosaic vegetation cover was
established by colonization from native local plant species.
3.1.1
Characteristics of Soils
The substrate of mine spoil heaps is composed of stones. The spoil heaps have a
graveley texture, so the plants growing there are deficient in water and nutrients
(0.65-2.28% Cox, 0.1-0.19% N). The input of heavy metals from the weathering
spoil material to the soil has been recorded. According to our analyses, the soil
contains high concentrations of metal residues. For example, Hg concentration
ranged from 72.7-4700 mg/kg and Cu from 40.0-11 300 mg/kg. Soil established
on the heaps has an alkaline reaction, with pH ranging from 7.3-8.1.
3.1.2
Contamination of Plants
Notable contamination of aboveground plant parts by mercury, copper and
sulphur was found on study heaps. The aboveground parts of dominant plant
species were analyzed.
Higher amounts of Hg and Cu occurred in Agrostis stolonifera than in Silene
vulgaris. Mercury concentration reached 11.2 mg/kg in the aboveground parts of
Agrostis stolonifera and reached 7-44 mg/kg in Silene vulgaris. Concentrations of
Cu were 87 mg/kg in Agrostis stolon if era and 18.5 mg/kg in Silene vulgaris.
3.1.3
Characteristics of Vegetation
Colonization of spoil heaps by higher plants depends on soil properties such as
weathering, chemical changes and microclimate (Schubert 1954; Ernst 1965). One
of the basic conditions is the ability of plant species to develop metal resistance
(Ernst 1990).
Plants colonies on Hg mine spoil heaps are very patchy. Vegetation cover is a
mosaic, depending on the weathering and development of soils. High percentages
of barren soil occur there. Species such as Agrostis stolonifera, Cardaminopsis
arenosa and Silene vulgaris dominate. Other plants, such as Hypericum