Impact of alien plants in Turkey assessed by the Generic Impact Scoring System

Ayşe Yazlık,Jan Pergl,Petr Pyšek

doi:10.3897/neobiota.39.23598

Abstract

In this paper, we present the impact categorizations of 51 alien plant species in Turkey, which were determined using the Generic Impact Scoring System (GISS). The evidence on environmental and socioeconomic impacts of these alien species was searched in literature. Impacts were classified into 12 categories (six for environmental and six for socioeconomic) and, within each category, the impact was assessed on a six degree scale. Environmental impacts were recorded for 80% of the species and mostly concern ecosystem processes (changes in nutrient or water availability and disturbance regimes), while socioeconomic impacts, identified for 78% of the species assessed, are typically associated with agricultural production or human health. Summed scores of individual species across categories of environmental and socioeconomic impacts were not significantly correlated. By taking into account the actual distribution of the assessed species, we evaluated the regional distribution of (potential) impacts in Turkey. The Black Sea region harbours the highest number of species with impacts (34 species, i.e. 67% of the total assessed for the whole country), 28 species were recorded in the Marmara, 21 in the Mediterranean, 17 in the Aegean and 12 in each of the South East Anatolia, Central Anatolia and East Anatolia regions. The species that have negative impact on forestry are only found in three regions. Altogether 21 species are agricultural weeds, but we only found evidence of a minor socioeconomic impact for some of them. Determining the impacts based on specific criteria (i) provides basis for objective risk assessment of plant invasions in Turkey, (ii) can be taken as early warning to combat these plants and (iii) contributes to the growing body of evidence of the impacts of alien plant species.

Highlights

In the last decade, evidence has accumulated about serious negative impacts of alien species on the environment, economy and human well-being in all parts of the world (Vilà et al 2010, 2011, Ricciardi et al 2013, Kumschick et al 2015b, Rumlerová et al 2016, Nentwig et al 2018)
According to recent European Union legislation, there will be a mandatory response by all member states to the threats that invasive species pose to biodiversity and ecosystem services
The vast majority of species assessed in this study can potentially have some impact in Turkey; of the 51 species scored, we found evidence in literature of environmental and socioeconomic impacts for 41 and 40 species, corresponding to 80% and 78%, respectively

Summary

Introduction

Evidence has accumulated about serious negative impacts of alien species on the environment, economy and human well-being in all parts of the world (Vilà et al 2010, 2011, Ricciardi et al 2013, Kumschick et al 2015b, Rumlerová et al 2016, Nentwig et al 2018). These impacts range from effects on individuals (e.g. competition, transfer of diseases, genetic and evolutionary changes) through populations, species and communities to those affecting whole ecosystems and their functioning (Parker et al 1999, Ehrenfeld 2010, Pyšek et al 2012, Simberloff et al 2013). To be included on this list, a full risk assessment, including evaluation of impact of a candidate species, has to be completed by experts, reviewed by members of the Scientific Forum and accepted by the European Commission and member states (EU 2014)

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Conclusion