Distribution of invasive plants in the Nitra river basin: threats and benefits for food production

Invasive plants are introduced multicellular organisms of the kingdom Plantae, which produce their food by photosynthesis. An invasive plant has the ability to thrive and spread aggressively outside its native range. A naturally aggressive plant may be especially invasive when it is introduced to a new habitat. The basic literature emphasizes mainly the ecological and environmental effects of invasive plants. Impacts of these plants on the food production have never been studied in details. The direct and indirect or potential effects of occurrence of invasive plants on food production have been analysed on basis of published data according to eight selected criteria: food, fodder for animals, food and drink additives, indirect support for food production, weeds on arable lands, meadow weeds, allergenic plants in food and toxic plants. The principal components analysis of habitat preferences of invasive plants in the Nitra river basin showed that the majority of invasive plants growing along rivers is edible (Fallopia spp., Helianthus tuberosus, Impatiens glandulifera) and invasive plants preferring drier agricultural fields or grasslands are toxic and/or allergenic with low or zero level of edibility (Ambrosia artemisiifolia, Heracleum mantegazzianum). The plants living in drier conditions may produce more toxins to protect the sources (eg. water) in their tissues than plants near water flows where there is abundance of sources.