New Study Challenges Invasive Plant Predictions in the Canary Islands
A study involving over 180 introduced plant species in the Canary Islands has revealed that invasive species may adapt to new climates more easily than previously thought. Conducted by the Institute of Natural Products and Agrobiology (IPNA-CSIC) and the University of La Laguna (ULL), the findings, published in the journal Ecography, cast doubt on existing models predicting invasion risks.
The research shows that many introduced plants can thrive in conditions different from their native habitats, challenging long-held theories. Historically, scientists have explored why some introduced species establish successfully while others do not, with Darwin’s pre-adaptation hypothesis suggesting that closely related species have a better chance due to shared ecological traits. Conversely, the climatic analogy hypothesis posits that a similar climate to their origin is necessary for establishment.
Louis S. Jay-García, an IPNA-CSIC researcher and co-author, remarked that for decades, it was assumed that understanding an introduced species’ evolutionary relationship or the climate of its origin was enough to predict its capacity for invasion. However, this study indicates that the reality is more complex, as many plants can expand their climate range upon arrival.
To test these hypotheses, the researchers examined 180 plant species across 82 genera in the islands, comparing them with native species using phylogenetic relationships, extensive distribution records, and high-resolution climate models.
One case studied involved the genus Andryala, which includes both the endemic Andryala pinnatifida and the introduced Andryala laxiflora. The latter has demonstrated a capacity to adapt to different climatic conditions in the archipelago.
Results show that Darwin’s pre-adaptation hypothesis alone cannot explain the success of introduced plants in the Canary Islands. Evolutionary relationships between native and introduced species provide little insight into their climatic niches. While many species from Mediterranean and neotropical regions find similar climates in the Canaries, a significant number thrive in entirely different conditions.
Specifically, more than one-third of the studied species occupy climates not found in their native ranges, and nearly two-thirds exhibit pronounced niche expansions. Researchers suggest this could be due to ecological release (the removal of natural competitors or predators), evolutionary adaptation to new environments, or local microclimates that support establishment outside usual climatic conditions.
Jairo Patiño, another IPNA-CSIC scientist, emphasised that biological invasions pose a major threat to island biodiversity. This study underscores that neither the kinship to native flora nor the climate of origin completely constrain introduced species’ ability to establish. He advocates incorporating this ecological flexibility into risk assessment models to enhance prevention and conservation strategies.
As introduced plants account for about a third of the flora in the Canaries, understanding the factors facilitating their establishment is crucial for managing future invasions. The authors conclude that current risk assessment models must account for species’ abilities to broaden their climatic niches once introduced, warning that relying solely on climatic similarity could underestimate their invasive potential amid climate change and increasing global mobility of organisms.
