ECONOMIC IMPLICATIONS OF THE SPREAD OF NON-NATIVE INVASIVE PLANT SPECIES IN THE UPPER BASIN OF THE BISTRITA MOUNTAIN RIVER, EASTERN CARPATHIANS, ROMANIA.

In this paper, we intended to analyze non-native plant species that spread uncontrollably and have a visible and quantifiable impact in the analyzed area. The analyzed plant species demonstrate a strong invasive character, overwhelming the native plant species. This fact leads to a loss of biodiversity at the local level, but especially to production loss of the useful biomass on the invaded land surfaces. The aim of this paper is to show a practical method of analysis and evaluation of economic losses at the local level caused by invasive plant species. At the same time, the paper wants to explain the factors that favor the spread of these invasive species on the territory of the investigated area. The most important factors contributing to the spread of these species are also noted. These are represented in particular by change in land use, climate change and uncontrolled, irresponsible growth in the gardens of these plant species. Invasive plant species such as Reynoutria japonica Houtt, Impatiens glandulifera Royle, Solidago canadensis L., are discussed. The populations of these species have a visible and quantifiable impact that can be found in the biomass production of the surfaces on which they grow. The uncontrolled spread of the populations made of these plant species leads to the damage of useful lands traditionally used for grazing or harvesting fodder for farm animals. In this paper, a method is outlined for the assessment of harvest losses on the surfaces affected by the populations of these plants. [ABSTRACT FROM AUTHOR]