**Abstract**

The study determined the influence of altitude on the content of heavy metals in selected plant species of the Tatra National Park (TNP). The metals (Cd, Cr, Cu, Ni, Pb, and Zn) were identified in two species of plants, i.e., in the moss (*Polytrichum formosum* Hedw.) and in the blueberry leaves (*Vaccinium myrtillus* L.). Plant samples were collected in two test areas every 100 meters of altitude of the area, starting from 1,000 m above sea level in the Lake Morskie Oko test area and from 1,100 m above sea level in the Kasprowy Wierch test area, and ending at 1,400 m above sea level for Lake Morskie Oko and 1,550 m above sea level for Kasprowy Wierch. The two test areas are different from each other in terms of natural and physico-geographical conditions (geological structure, landform, climatic conditions, etc.). The conducted research shows that the content of heavy metals in the studied species of plants increases with the altitude above sea level. Both *P. formosum* Hedw and *V. myrtillus* L. can be good phytoindicators in mountainous areas. In the tested plant species, the contents of heavy metals were also found to be higher than the natural contents, which is most likely related to long-range emission. Long-distance transport of pollutants causes that important natural protected areas, such as the Tatra National Park, are exposed to excessive pollution, including the accumulation of heavy metals in plants.

**Keywords:** heavy metals, plants, mountains, *P. formosum* moss, *V. myrtillus* blueberry, the Tatras, protected areas

## **1. Introduction**

There are numerous places of natural value in the world. They are often protected areas, such as national parks or nature reserves. However, it should be remembered that such areas are not free from the influence of human activities. In protected areas, humans do not have a direct negative impact on the natural environment, but industrial and automotive emissions reach these areas. These are the so-called long-range emissions, as a result of which fine dust particles are transported over distances of several hundred kilometers [1–3]. Dust particles contain heavy metals, the spreading of which over long distances is related to the long duration of dust pollution in the atmosphere. The length of time during which dust particles remain in the atmosphere depends on the particle size, terrain configuration, and meteorological conditions. Low pressure, strong wind, significant cloud cover, and high precipitation contribute to the spreading of pollutants over long distances [2]. The length of time during which heavy metals remain in the environment differs for individual metals. Lead and cadmium are metals that remain in the atmosphere for a long time and are characterized by the very small diameter of their particles. They are easily transported over long distances and, therefore, contaminate the environment on a global scale [2, 3].

As a result of the transport of pollutants over long distances, areas considered to be of natural value and protected may have a problem with an increased amount of metals in soil or vegetation. An example of such an area is the Tatra National Park, where we are dealing with long-range emissions. The Tatra National Park is one of 23 national parks in Poland. It has the highest regime of all forms of nature protection in Poland. Together with the Slovak part of the Tatra National Park (Tatranský národný park), it constitutes a UNESCO biosphere reserve. Its natural value is evidenced by the fact that for many centuries a large part of this area has not been directly changed by man, and this condition has continued to this day. The small area of the national park (211 km<sup>2</sup> ) contains a wealth of flora and fauna, often endemic and relict species, as well as a variety of landscapes. This is the result of, among other things, the specific geographic location of the Tatra Mountains in Europe, which is influenced by, among other factors, transitional climate and overlapping ranges of various flora and fauna. Although human pressure on the natural environment of this area concerns the in situ impacts related to tourism, the entire area of the national park is affected by external influences.

Pollutants from the Czech Republic, Slovakia, and the Silesia region are transported to the TNP area, where they fall and cause increased metal content in soils and plants. In Slovakia and the Czech Republic, the industrial sector is dominated by metallurgy, and chemical, defense, electrical, and electronic industries, as well as by the production of aluminum, nickel, and copper. These industries are a source of heavy metals in the natural environment.

The metals particularly dangerous to living organisms include cadmium, chromium, copper, nickel, lead, and zinc. Currently, the content of these metals in soils and plants is higher than their natural content [4, 5]. The excessive amount of the mentioned heavy metals in the natural environment results from industrial activity and motorisation, and leads to irreversible changes in ecosystems [6, 7].

The phytoindication method is commonly used in environmental monitoring. Technical monitoring is reduced to the direct measurement of pollutants, while biomonitoring supplements technical monitoring and can be carried out within any number of stations. It provides direct information on the level of soil and plant contamination. In this study, the monitoring of contamination with metals was based on two plant species commonly found in the TNP (the European blueberry *V. myrtillus* L. and the moss *P. formosum* Hedw.).

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

Species recommended as bioindicators (phytoindicators) should meet, inter alia, the following criteria:


The selection of indicator plants was based primarily on the prevalence of given species in the Tatra National Park, followed by the criterion of their ability to accumulate heavy metals. Literature data [8–11] as well as our own observations [12, 13] have provided some indication of the heavy metal accumulation capacity of selected plant species. The moss species *Pleurozium schreberi*, recommended in the European monitoring programme, has been abandoned owing to its wide geographical range. Despite the fact that it is a very good indicator of environmental pollution,, it nevertheless occurred within a too small number of sites in the studied mountainous area. In particular, it rarely appeared within dense spruce stands. On the other hand, samples of the moss *P. formosum* Hedw. as one of the most widespread species in the forest areas of the Tatra National Park were collected. The samples of the plant material were collected at the end of September, that is at the end of the growing season in the mountains. Markert and Weckert [14] provide some clue as to the date of moss sampling. They state that the heavy metal content in the *P. formosum* Hedw. is subject to significant seasonal fluctuations, and this variation is often more important than the variation between sites. Therefore, in order to obtain comparable results, it is recommended that moss is sampled for biomonitoring purposes in the same period of time, preferably at the end of the plant growing season, i.e. at the turn of September and October.

The main objective of the study is to determine the content of heavy metals in two plant species depending on the absolute altitude in protected mountain areas.
