New paper published in Ecology: Introduced mangroves escape damage from marine and terrestrial enemies
Davidson recently published a new paper in the journal Ecology titled "Introduced mangroves escape damage from marine and terrestrial enemies." In their native range, red mangroves are key habitat-creating foundation species and provide numerous ecosystem services. However, introduced red mangroves in Hawaii completely transform native beaches, lagoons, and other habitats into dense mangrove forests. These transformations alter native biodiversity, ecosystem function, and even threaten Native Hawaiian fishponds. Introduced mangroves also appear extremely dense and productive in Hawaii and earlier work suggests few enemies appear to prey on mangroves.
The enemy release hypothesis suggests that some invaders may become more "successful" (e.g., productive and fecund) in an invaded location if they are introduced without their natural enemies.
In this study, Davidson, Mark Torchin (STRI Panama), and Celia Smith (University of Hawaii at Manoa) investigated the enemy release hypothesis using red mangroves (Rhizophora mangle) as a model system. Specifically, they compared the prevalence of herbivores and herbivory damage between 8-10 introduced (Hawaii) and native mangrove sites (Florida, Belize, Panama). They found 10 times less damage and far fewer enemies in introduced mangroves than native mangroves, in support of the enemy release hypothesis. These results were consistent across several mangrove structures (roots, leaves, propagules, etc.) and between different types and functional groups of enemies (marine vs. terrestrial; herbivores, pathogens, etc.). You can read more about the study here.
Davidson TM, Smith CM, Torchin ME (2022). Introduced mangroves escape damage from marine and terrestrial enemies. Ecology: e3604.