**Author details**

thone, a chemical in the group of quassinoids [9] mainly present in the Simaroubaceae family. Several studies have shown that ailanthone is toxic for many plant species, including weeds, crops and trees [9, 87]. It is believed that, by producing and releasing ailanthone through its tissues largely through the roots, *A. altissima* has an allelopathic effect on nearby plant species, slowing their growth and outcompeting them [9]. Considering its high phytotoxicity, ailanthone shows potential as a possible future natural product herbicide, although its nonselectivity observed in multiple studies would present an obstacle if not resolved in some way. In addition, its rapid biodegradability could be a positive feature from the conservational aspect as it has a short, lasting effect in the environment but a negative one if possible applications

Many non-native species have been introduced for intentional ornamental and horticultural purposes (e.g. *Ailanthus altissima* and *Paulownia tomentosa*) [31, 48, 81]. Such species, due to their reproductive potential and regenerative capacity, soon increase in density. After some years of their uncontrolled spread, the cultivation loses importance; thus legal introduction

IAS management must take into account all impacts of new species in a certain ecosystem. Natural resource management bodies should base their management plans on the real effects of a particular species in an ecosystem and not on traditionally repeated claims of non-selective negative effects of alien species. All species have some useful potential in an ecosystem, and many have easily defined services. Although some non-native species can cause serious problems that should be taken into account, a wider perspective on the role of each species in an ecosystem is needed. Their role is also mixed with new challenges arising from other environmental changes such as climate changes and human interventions. Land managers must focus more on the function of a species in an ecosystem than on their origin. As our understanding of biological invasions is growing, our capability to describe the ecological and economic consequences is more precise enabling the environmental managers to make objective decisions about IAS management.

as a herbicidal compound would be taken into account [88].

**4.9. Ornamental**

**5. Conclusion**

and commerce are stopped.

50 Ecosystem Services and Global Ecology

**Acknowledgements**

**Conflict of interest**

This study was supported by the Municipality of Poreč.

The authors declare no conflict of interest related to the present paper.

Barbara Sladonja1 \*, Danijela Poljuha1 and Mirela Uzelac2

\*Address all correspondence to: barbara@iptpo.hr

