Biogeographic origins and drivers of alien plant invasions in the Canary Islands

Abstract

Aim Understanding the historical and contemporaneous drivers of invasion success in island systems can decisively contribute to identifying sources and pathways that are more likely to give rise to new invaders. Based on a floristic‐driven approach, we aimed at determining the origins of the invasive alien flora of the Canary Islands and shedding light in the mechanisms shaping their distribution within the archipelago. Location Canary Islands. Taxon Vascular plants. Methods An updated checklist of the invasive alien flora of the Canary Islands was assembled along with complementary information related to the native biogeographical regions, stage of invasiveness and dates of naturalization. Statistical models were employed to describe differences in the number of species over space and time. We also used multivariate techniques to evaluate competing hypotheses related to the mechanisms driving invasive floristic composition within the archipelago. Results We provided a list of 149 alien plant species with a certain degree of invasiveness. The greatest number of invasive species originated from the Neotropics followed by the Cape Region, tropical Africa and the Mediterranean Basin. We observed a slow but steady increase in numbers of invasive species until the 1950s, followed by a stronger rise thereafter. In order to explain composition dissimilarity of the invasive flora among islands, a climatic matching hypothesis was fully supported, with geographic isolation and contemporary human‐mediated connectivity hypotheses receiving less and null support respectively. Main Conclusions We showed that the Neotropical region is the main source of plant invasions to the Canary Islands, outnumbering those from other regions with a Mediterranean‐type bioclimate. The assembly of the invasive flora within the archipelago appears to be driven primarily by climate, but with geographic distance also playing a role. This study calls for archipelago‐dependent assessments of the underlying mechanisms that contribute to plant invasion success within insular systems.

Road Impact on Plant Colonization in the Arid Timanfaya National Park

“…or Agave sp., are also present. These invasive species were introduced in the Canary Islands for various purposes, including marking land boundaries and properties, and their expansion has been facilitated by these anthropogenic corridors or roads in the archipelago [40,41]. Nevertheless, out of the 16 existing introduced species recorded in the present study, only 6 of them were invasive (Agave americana, Atriplex semibaccata, Nicotiana glauca, Opuntia dillenii, Rumex lunaria, and Pelargonium capitatum) (Table A1).…”

Effects of climate change on the distribution of plant species and plant functional strategies on the Canary Islands

“…Moreover, in high‐elevation areas, climate change‐induced high rabbit densities are already threatening the persistence of native plant species (Cubas et al, 2018), as well as in most other ecosystems of the archipelago (Cubas et al, 2019). Therefore, additional threats, such as invasive species, habitat loss and resource overexploitation (Fernández‐Palacios, Kreft, et al, 2021; Morente‐López et al, 2023), strongly influence whether species can shift their range to climatically suitable areas in the future. Additionally, we acknowledge that we analysed the native species' realised niches and not their fundamental niches.…”

Alien flora of Nigeria: taxonomy, biogeography, habitats, and ecological impacts

“…Studies have shown that habitat filtering may support the naturalization and invasion of alien plants if the native and invaded ranges share similar ecological conditions (Hejda et al 2015;Buckley and Catford 2016;Divíšek et al 2018). Several countries, including Ghana, South Africa, and the Canary Islands, also reported that the largest percentage of naturalized alien flora in their respective study areas are of Neotropic origin (Henderson and Wilson 2017;Ansong et al 2019;Morente-López et al 2023).…”