Economic valuation of selected invasive species

Abstract

The spreading of invasive species causes serious economic and environmental problems in our days. The recognition of these negative effects, and protection against them are based on estimates, assessing the extent of the damage. Black locust (Robinia pseudoacacia L.) and tree of heaven (Ailanthus altissima Mill.) are widespread and extremely dangerous tree species in Hungary. In our research we analyzed economic potential and cost of restraint of the above mentioned species. During the data collection we sent thematically compiled questionnaire to the relevant state institutions (10 national park directorates and 22 state forest companies). In addition, other publicly available background information was collected and telephone interviews were carried out complementing of data set. Questionnaires covered items of income and expense (15 items) in aspect of the analyzed species for the 2009–2013 period. A significant number of incoming data came from national park directorates, but vast majority of the state forest companies did not give information despite of multiple requests. During evaluation of data, we found that costs of black locust reduction were so high (sometimes hundreds of millions of HUF) that those could not be compensated by revenue from the sale. However, in the case of the state forest companies, incomes were several times bigger than costs in each year. Judgment of tree of heaven was negative in all areas. They could not be sold, so no revenue was derived from their presence, but reduction was very expensive.