First nutritional report of a tree species (Sacoglottis holdridgei Cuatrec. Humiriaceae) on Isla del Coco National Park, Costa Rica

Isla del Coco is 500 km from Costa Rica's continental territory in the Western Pacific. As a National Park in absolute conservation, it has unique conditions for studying vegetation, ecosystem restoration, and the effects of climate change. Sacoglottis holdridgei Cuatrec. (Palo de Hierro) is an endemic tree that has shown a mortality pattern related to pathogens on the Island based on previous phytosanitary research. We performed a foliar nutritional analysis to evaluate the relationship between tree nutrition and observed mortality in the field. We collected leaf samples from the middle crown of the tree of two populations of ten individuals, each of healthy and diseased trees. The leaves were dried and stored before being analyzed in the laboratory. The results did not show differences in nutritional contents between healthy and diseased trees. These similarities in nutritional contents between the two populations studied allow us to hypothesize about the adaptation mechanisms of S. holdridgei to grow in acidic and poor soils of the Island. These adaptations on nutrients use have been observed in other species that live on the mainland.