**3. Results**

The mean content of heavy metals in plants is presented in **Table 2**.

On the basis of the mean metal content in plants, calculated from all the collected samples, the following series of heavy metal concentrations were obtained:

Zn > Pb > Cr > Cu > Ni > Cd for the moss *P. formosum* Hedw*.*

Zn > Cr > Pb > Cu > Ni > Cd for the European blueberry *V. myrtillus* L.

The metal concentration series look similar for both plant species with the difference in lead and chromium content, where the moss *P. formosum* Hedw. accumulated more lead than chromium, while in the case of the European blueberry


#### **Table 2.**

*Mean concentrations of heavy metals in the moss species* Polytrichum formosum *Hedw. And in the European blueberry* Vaccinium myrtillus *L.*

*V. myrtillus* L. the opposite was true (the European blueberry accumulated more chromium than lead). For both plant species, the last three metals presented in the series were similarly accumulated (higher amounts of copper compared to nickel and cadmium, and nickel compared to cadmium).

Comparing the mean metal contents in both plant species, it can be seen that the moss *P. formosum* Hedw. was characterized by a greater accumulation of metals (2.1 μg Cd/g dm, 21.5 μg Cr/g dm, 16.4 μg Cu/g dm, 14.2 μg Ni/g dm, 25.6 μg Pb/ g dm, 60.4 μg Zn/g dm) compared to the European blueberry *V. myrtillus* L. (1.5 μg Cd/g dm, 15.1 μg Cr/g dm, 11.5 μg Cu/g dm, 11.3 μg Ni/g dm, 13.9 μg Pb/g dm, 36.1 μg Zn/g dm). Both the moss *P. formosum* Hedw. and the European blueberry *V. myrtillus* L. accumulated zinc in the highest amounts (60.4 and 36.1 μg Zn/g dm for the moss and the European blueberry, respectively), and cadmium in the smallest amounts (2.1 and 1.5 μg Cd/g dm).

Analyzing the data in **Table 2**, it can also be concluded that both plant species accumulated greater amounts of metals in the Morskie Oko test area than in the Kasprowy Wierch test area. For the same absolute altitudes, the content of heavy metals in plants, in particular of lead (1.8), nickel (1.7) and zinc (1.6) for the moss and of zinc (1.7) and lead (1.6) for the European blueberry, were almost twice as high in the Morskie Oko test area (**Table 3**). Smaller differences in the metal content in plants between the test areas were observed for cadmium, copper, and chromium.

The absolute altitude coefficient was calculated as the quotient of the heavy metal content in plants in the test areas for a given altitude (e.g. for Cd 1,100 m asl, the coefficient is the quotient of the Cd content in the MO test area to the Cd content in the KW test area for an altitude of 1,100 m asl).

The values of the heavy metals plant enrichment factor metals depending on the absolute height were determined as the second factor. This coefficient was calculated as the quotient of the heavy metal content for the lowest altitude to the highest metal content in the plants for a given test area, e.g. Cd 1,400 m asl to Cd 1,000 m asl for MO). The values of the enrichment coefficient are presented in **Table 4**.

The enrichment factors, calculated for all absolute heights, reach a value greater than or equal to 1.0. This indicates the presence of heavy metals accumulation in plants that is lower or similar to the highest altitude tested for a given test area (1,400 m asl for MO and 1,550 m asl for KW). The increase in the accumulation of metals in plants along with altitude was observed for the two plant species and for


**Table 3.** *Absolute altitude coefficients.*


Polytrichum formosum *and* Vaccinium myrtillus *as Phytoindicators of Pollutants… DOI: http://dx.doi.org/10.5772/intechopen.99962*

#### **Table 4.**

*Heavy metals plant enrichment factors.*


#### **Table 5.**

*Heavy metals plant accumulation coefficients.*

each tested element. The increase in the content of all metals in plants occurs for two test areas.

**Table 5** summarizes the plant accumulation coefficients calculated as the ratio of the content of a given metal in the moss to the content of the same metal in the European blueberry for the same absolute height and the same test area.

On the basis of the calculated accumulation coefficients it is clearly visible that the moss *P. formosum* Hedw. has a greater ability to absorb and accumulate heavy metals than the European blueberry *V. myrtillus* L. For each of the heavy metals determined, it was the moss that accumulated greater amounts. The largest differences in the accumulation of metals between the tested plants were observed for lead (a coefficient of 1.6–1.9) and zinc (a coefficient of 1.6–1.8), and the lowest for nickel (a coefficient of 1.1–1.4). The coefficients obtained for cadmium, chromium, and copper were similar and fell within the range of: 1.2–1.6.

Based on the Kolmogorov–Smirnov test (**Table 6**), distributions close to normal were recorded only for the content of Cd in the moss and Cu in the European blueberry. The other variables had distributions deviating from the normal distribution. Therefore, in order to determine the similarity, non-parametric tests were used in further analysis.

A statistically significant positive relationship was found between the Cd content and altitude in the moss (rho = 0.227; p = 0.023). There was no statistically significant relationship between the altitude and the content of other elements (**Table 7**).


#### **Table 6.**

*Assessment of compliance with the normal distribution - Kolmogorov–Smirnov test for one sample.*


#### **Table 7.**

*Assessment of the relationship between the variables (metal-altitude) - Spearman's coefficients.*


#### **Table 8.**

*Mann–Whitney test results for species.*

Polytrichum formosum *and* Vaccinium myrtillus *as Phytoindicators of Pollutants… DOI: http://dx.doi.org/10.5772/intechopen.99962*

There were statistically significant differences between the locations for both the moss and the European blueberry. Each element had a lower concentration in the measurements at Kasprowy Wierch than at Lake Morskie Oko (**Table 8** and **Figure 2**).

**Figure 2.**

*Assessment of the relationships between variables (metal-altitude) - scatter dot plots for Cd, Cr, Cu, Ni, Pb and Zn.*


**Table 9.**

*Mann–Whitney test results for location.*

Considering the differences in the accumulation of metals by the moss and the European blueberry, statistically significant differences were obtained for each location. Moss accumulated more of all the tested metals compared to the European blueberry. The only exception was the Ni content in the Kasprowy Wierch test area, for which no statistically significant differences were found in accumulation by the moss and the European blueberry (**Table 9**).
