Abstract
Gardening is a popular pastime, but commercial horticulture is responsible for the introduction of alien species and contributes to invasions in a variety of ways. Although an extensive international literature is available on plant invasions, it is still important at the national level to examine the influence of local factors. Accordingly, 17 nurseries in Estonia that cultivated and sold perennial alien species were selected, and a list of species and prices was compiled. The relationships between species status, and factors such as their abundance in the wild were examined statistically. A qualitative list of the nationally problematic species among herbaceous perennials was also completed. A total of 880 taxa were recorded, of which 10.3% were native and 89.7% alien. In all, 87.3% of the alien species were still confined to cultivated areas. The ecological and socio-economic characteristics of the taxa were described, and lists of the families of casual, naturalised and invasive aliens were provided. Both native and increasing wild alien species have a very similar profile on the market. Alien species that are less expensive, widely available and have more cultivars per species on the market are also more likely to escape. The invasive status and abundance of escaped aliens in an area increases with residence time. In general, socio-economic factors create new and reflect previous propagule pressures from commercial horticulture, which continuously increase the likelihood of alien species surviving and invading new areas. Our findings suggest that these national socio-economic market-related factors explain much of the invasiveness of various perennial ornamental species, and therefore regional and national authorities urgently need to regulate and control the ornamental plant trade to diminish the risk of new invasions.
Highlights
Biological and human-mediated mechanisms in invasions of alien plant species are interdependent, and as a result, it is difficult to predict where and why such invasions will occur
The alien species status and other characteristics connected to alien species’ invasiveness on Estonian territory were used as applied in Estonian Alien Flora (Ööpik et al 2008), after which the invasive status of alien species was used in the sense proposed by Richardson et al (2000) and Pyšek et al (2004)
The results show that two groups - native and alien species found outside cultivation of any status from casual to invasive - have a similar market profile, in contrast to nonescaping alien species
Summary
Biological and human-mediated mechanisms in invasions of alien plant species are interdependent, and as a result, it is difficult to predict where and why such invasions will occur. The study of the economic uses of plant species that are invasive in various parts of the world has established that most plant invaders are ornamentals (Weber 2003) These species have been introduced for horticultural use by nurseries, botanical gardens, and individuals (Reichard and White 2001). When the variations in invasion rates were partitioned according to a range of explanatory variables, it was found that only national wealth and population density were statistically significant (Pyšek et al 2010). These predictors reflect the intensity of human activities, in which the horticultural trade is a relevant component.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
