Pouteau Robin, Adrien E., Ah-Peng C., Albert S., Flores O., Laforgue B., Lavergne C., Meyer J. Y., Regen A., Rojat Margaux, Roussel S. (2026). Trait-dependent declines of threatened endemic trees following plant invasion on a tropical oceanic island. Biological Conservation, 315, p. 111665 [10 p.]. ISSN 0006-3207.
Titre du document
Trait-dependent declines of threatened endemic trees following plant invasion on a tropical oceanic island
Année de publication
2026
Auteurs
Pouteau Robin, Adrien E., Ah-Peng C., Albert S., Flores O., Laforgue B., Lavergne C., Meyer J. Y., Regen A., Rojat Margaux, Roussel S.
Source
Biological Conservation, 2026,
315, p. 111665 [10 p.] ISSN 0006-3207
Biological invasions are a leading cause of the ongoing biodiversity crisis, and particularly so on islands. However, the role of invasive alien plants (IAPs) as a driver of native plant declines and extinctions remains unclear. The inherently slow and gradual nature of plant extinctions, especially that of long-lived woody species, could be a reason. Here, we examined temporal trends in subpopulations of 28 threatened endemic tree (TET) taxa. We questioned the frequency with which they decline in association with IAPs on Reunion Island (SouthWest Indian Ocean), and asked whether the most susceptible TET taxa exhibit characteristics that could reveal the underlying ecological mechanisms. We resurveyed 182 historically described subpopulations and tested whether observed trends of juvenile and adult TETs correlate with the abundance in IAPs using path analyses, while distinguishing TET taxa with respect to their leaf-height-seed characteristics and extinction risk. The trend of adult TETs was not affected by IAPs but that of juvenile TETs was negatively correlated with the abundance of IAPs in the understory layer. This was particularly the case for TET taxa with conservative resource-use strategies (low specific leaf area or low maximum height), whose juveniles might be particularly susceptible to competition with IAPs, but not for TET taxa with large seeds, whose metabolic reserves make seedlings more likely to attain a critical size. These findings suggest that IAPs can significantly contribute to the extinction dynamics of trees, primarily by limiting regeneration through competitive exclusion, and that their impacts vary depending on the traits of the affected taxa.
Plan de classement
Sciences du milieu [021]
;
Sciences du monde végétal [076]
;
Etudes, transformation, conservation du milieu naturel [082]
Description Géographique
REUNION ; OCEAN INDIEN ; ZONE TROPICALE
Localisation
Fonds IRD [F B010096050]
Identifiant IRD
fdi:010096050
