399
arsenic and antimony. Unlike BAF, the highest BTF in Centaurea leucomalla for Sb
has a value of 1.02. From the other side, BTF was higher for As and Sb showing that
the transfer of these elements from roots to the flower was more significant than Tl.
Table 13.12 presents the results of the contents of As, Sb, and Tl in soil and in all
parts of Centaurea kavadarensis, Onobrychis degenii, and Knautia caroli-rechingeri
and calculations for the bioaccumulation (BAF) and biotransfer factor (BTF). From
these results it can be concluded that the bioaccumulation factor (transfer of the element from soil to all parts of the plant) was very low for As (0.023 in Onobrychis
degenii and 0.073 in Knautia caroli-rechingeri, while for Centaurea kavadarensis it
could not be calculated because the contents of As in the parts of the plants were
below the detection limit) and for Sb. From the other side, BAF for thallium was
higher ranging from 0.322 in Onobrychis degenii and 0.618 in Knautia carolirechingeri, and the highest values of 3.819 were found for Centaurea kavadarensis.
Biological transfer factor (BTF), which represents the ratio between the content
of that element in the flower (or seeds) and in the root, was the highest also for Tl
(from 0.048 in Knautia caroli-rechingeri to 0.737 in Centaurea kavadarensis)
which shows their capability to accumulate high amounts of Tl. Probably this
behavior of thallium could be explained by the interpretation given by Madejon
et al. (2007) that when Tl was present in soils it may be easily taken up by plants
because it generally presents as thermodynamically stable Tl(I), an analogue to
potassium, or by the explanation that thallium(I) has a very low stability that is
constant with both organic and inorganic ligands and therefore should be easily
extractable from the leaves (Kaplan and Mattigod 1998; Nriagu 1998; Scheckel
et al. 2004; Bačeva et al. 2014b).
13.4 Conclusion
The aim of this study was to increase the knowledge about the behavior of a wide
range of elements with special attention paid to As, Sb, and Tl in seven local endemic
plant species: Viola allchariensis G. Beck, Viola arsenica G. Beck, Thymus alsarensis Ronn., Centaurea leucomalla Bornm., Onobrychis degenii Dörfler, Knautia
caroli-rechingeri, and Centaurea kavadarensis, and one subendemic species – Viola
macedonica Boiss. and Heldr., in the environment of the As-Sb-Tl mining area
where they are exposed to large amounts of these elements present in the soil (the
locality of Allchar, Republic of North Macedonia).
The data showed that Viola species are able to hyperaccumulate toxic elements
in their roots, stems, leaves, flower, and seeds. The content of As and Sb was significantly higher in the roots and seeds, while the content of Tl was significantly higher
in the leaves, flowers, and seeds in all Viola species. Data from the extractions for
plant-available elements of soil samples performed in water, HCl, and buffered
DTPA solutions show that As was the most extractable from HCl solution and the
extractability of Tl was similar for all Viola species, while the extractability of Sb
was much lower than that of As and Tl.
13 Accumulation Abilities of Endemic Plant Species from the Vicinity of an As-Sb-Tl…
arsenic and antimony. Unlike BAF, the highest BTF in Centaurea leucomalla for Sb
has a value of 1.02. From the other side, BTF was higher for As and Sb showing that
the transfer of these elements from roots to the flower was more significant than Tl.
Table 13.12 presents the results of the contents of As, Sb, and Tl in soil and in all
parts of Centaurea kavadarensis, Onobrychis degenii, and Knautia caroli-rechingeri
and calculations for the bioaccumulation (BAF) and biotransfer factor (BTF). From
these results it can be concluded that the bioaccumulation factor (transfer of the element from soil to all parts of the plant) was very low for As (0.023 in Onobrychis
degenii and 0.073 in Knautia caroli-rechingeri, while for Centaurea kavadarensis it
could not be calculated because the contents of As in the parts of the plants were
below the detection limit) and for Sb. From the other side, BAF for thallium was
higher ranging from 0.322 in Onobrychis degenii and 0.618 in Knautia carolirechingeri, and the highest values of 3.819 were found for Centaurea kavadarensis.
Biological transfer factor (BTF), which represents the ratio between the content
of that element in the flower (or seeds) and in the root, was the highest also for Tl
(from 0.048 in Knautia caroli-rechingeri to 0.737 in Centaurea kavadarensis)
which shows their capability to accumulate high amounts of Tl. Probably this
behavior of thallium could be explained by the interpretation given by Madejon
et al. (2007) that when Tl was present in soils it may be easily taken up by plants
because it generally presents as thermodynamically stable Tl(I), an analogue to
potassium, or by the explanation that thallium(I) has a very low stability that is
constant with both organic and inorganic ligands and therefore should be easily
extractable from the leaves (Kaplan and Mattigod 1998; Nriagu 1998; Scheckel
et al. 2004; Bačeva et al. 2014b).
13.4 Conclusion
The aim of this study was to increase the knowledge about the behavior of a wide
range of elements with special attention paid to As, Sb, and Tl in seven local endemic
plant species: Viola allchariensis G. Beck, Viola arsenica G. Beck, Thymus alsarensis Ronn., Centaurea leucomalla Bornm., Onobrychis degenii Dörfler, Knautia
caroli-rechingeri, and Centaurea kavadarensis, and one subendemic species – Viola
macedonica Boiss. and Heldr., in the environment of the As-Sb-Tl mining area
where they are exposed to large amounts of these elements present in the soil (the
locality of Allchar, Republic of North Macedonia).
The data showed that Viola species are able to hyperaccumulate toxic elements
in their roots, stems, leaves, flower, and seeds. The content of As and Sb was significantly higher in the roots and seeds, while the content of Tl was significantly higher
in the leaves, flowers, and seeds in all Viola species. Data from the extractions for
plant-available elements of soil samples performed in water, HCl, and buffered
DTPA solutions show that As was the most extractable from HCl solution and the
extractability of Tl was similar for all Viola species, while the extractability of Sb
was much lower than that of As and Tl.
13 Accumulation Abilities of Endemic Plant Species from the Vicinity of an As-Sb-Tl…