The Paradox of the Alien Plant Leucaena leucocephala subsp. glabrata (Rose) S. Zárate in Sicily: Another Threat for the Native Flora or a Valuable Resource?

Abstract

With this contribution, an updated picture of the rapid expansion of Leucaena leucocephala subsp. glabrata in Sicily is provided. On the one hand, this is a quite worrying sign, as this woody species figures among the world’s worst invasive alien species. On the other hand, the species shows interesting potential for production purposes (for wood, biomass and for feeding livestock), also considering its nitrogen fixation ability. Consequently, the two opposite options to cope with this species, i.e. cultivation and control/eradication, should accurately take into account the possible uses as well as its invasive behaviou

Allelopathy and Allelochemicals of Leucaenaleucocephala as an Invasive Plant Species

“…L. leucocephala threatens native vegetations and biodiversity in the invaded areas [11,27,34]. The species richness in L. leucocephala invaded areas was lower than that in its unin-vaded areas, and the establishment of the native plant species was hardly observed in the L. leucocephala invaded areas [31,34,45,46].…”

“…leucocephala has already naturalized in more than 130 countries in the Pacific Ocean region, Asia, South and Central America, Caribbean, Africa, Middle East, Australia, and Europe, and the number of naturalized countries is still increasing [1,2]. Ecosystems in islands are very vulnerable against invasive plant species like L. leucocephala, and L. leucocephala has caused serious problems in native plant communities in tropical and subtropical oceanic islands [27,[31][32][33][34][35][36]. L. leucocephala is recognized as being a weed of roadsides, hillsides, forest margins, riparian habitats, deserted lands, and abandoned lands (Figure 2).…”

“…However, despite the economic values of L. leucocephala, the species is listed in the 100 of the world's worst invasive alien species [1,2]. The species was reported to be an aggressive colonizer, to form dense monospecific stands, and threaten native plant communities, especially in oceanic islands [8,27]. It has been suggested that allelopathy of L. leucocephala may contribute to its high invasive potential [28,29].…”

A crop for a forest: Opuntia ficus-indica as a tool for the restoration of Mediterranean forests in areas at desertification risk

“…On the one hand, such exotic species may become invasive and seriously threaten native species and habitats, thus leading to expensive control and eradication programs (Simberloff et al, 2013). On the other hand, even invasive species may be useful for restoration or conservation purposes under some circumstances, therefore generating a conservation trade-off and calling for a better understanding of their functional role in ecosystem dynamics and plant community assembly (Schlaepfer et al, 2011;Vimercati et al, 2020;Badalamenti et al, 2020a). Although the risk of a generalized and uncritical approach to non-native species still exists, there is increasing consensus in the scientific community on the need for evidence-based assessment of alien species' invasiveness and related harmful impacts (e.g., Kumschick et al, 2023).…”