PS 38-209 - CANCELLED - Constraints to reproduction and recruitment of the wetland species Annona glabra in Puerto Rico

Background/Question/Methods

Annona glabra is a wetland plant species that can be found in fresh and brackish water wetlands throughout the Neotropics. There is evidence that some brackish wetland plant species have been affected by changes in salinity and hydroperiod associated with sea level rise. In Puerto Rico, we have observed no juvenile recruitment of A. glabra in some localities despite regular fruit production. To determine what are the factors influencing reproduction, and recruitment of the species we established seedlings plots, determined phenology patterns and soil abiotic and biotic factors (soil salinity, water level and soil microbiota). We followed the trajectory of 75 seedlings of A. glabra in 14 grids over a period of 6 months.

Results/Conclusions

Phenological patterns showed that there is no limitation on reproduction, however, even though there is germination, seedlings do not survive. Germination and recruitment data showed that there was no relationship between abiotic factors (temperature, pH, light, and soil moisture) with the density, survival, and growth of seedlings (r=0.04, p >0.05). Of the 75 seedlings 86% died in the following 5 months and 100% died before 6 months. However, greenhouse experiments showed that seedlings can tolerate medium to high levels of salinity. Recently, we discovered other factors that deserve to be explored, such as the presence of wasps (Bephatelloides sp) and beetles (Coccotrypes rhizophorae) in the seeds of A. glabra. We observed that some seeds contain all stages of the life cycle of the wasp species. There is a possibility that seed infection by these species interferes with germination and potentially could reduce seedling establishment. Given the ecological importance of coastal wetland ecosystems and the vulnerability of species in these habitats under the climate change scenario understanding what factors are limiting A. glabra in Puerto Rico is critical to develop better conservation strategies.