Effects of Light on the Transition From Sapling to Adult Prunus cerasus: Implications for Managing Invasion in Los Alerces National Park, Argentina

Long-distance seed dispersal in invasive plants is frequently associated with frugivory. Flowering and fruit production are related to light availability. Therefore, obtaining information about when and in which conditions propagules start to produce fruits is relevant for managing invasions. Prunus cerasus is invading Andean–Patagonia forest. Here, we estimated the age of transition from the juvenile to adult phase (first bloom) of P. cerasus saplings growing under different canopy cover conditions in Los Alerces National Park (Argentina). By counting flowers and measuring the basal diameter of 116 young individuals from three sites of the Park, we determined that 80% of individuals with a 2 cm basal diameter flowered under low cover. In contrast, 4 cm of diameter is required under high-cover conditions. Using dendrochronology, we determined that a basal diameter of 2 cm corresponded to a 10-year-old individual and a basal diameter of 4 cm corresponded to a 20-year-old individual. By recording light under low- and high-cover conditions, we found that cover determined daily light, the median daily light intensity, and photoperiod in all the sites. Therefore, control programs should prioritize the removal of P. cerasus in sites with low canopy cover, removing saplings before they reach a 2 cm basal diameter.