Seed rain and phenology in an invasive species removal experiment in Mona Island Reserve, Puerto Rico

Background/Question/Methods   As part of an experiment to test the effects of removal of an invasive grass species (Megathyrsus maximus) in cacti and other native plants populations in the Eastern coastal area of Mona Island, we collected seeds and plant parts in tray traps, adjacent to the experimental plots (control, clipping, and total removal of the grass). Monthly samples were separated and classified in the laboratory; with the exception of seeds that were counted and weighted, other plant parts were oven-dried (60 ºC) for biomass measurement.

Results/Conclusions   One year results show a reduction in seed rain in control plots, independently of the time of the year; treatments affect leaf biomass collection in a more complex way. Removal treatments and time of the year have an effect on reproductive biomass collection, somewhat following the pattern of monthly precipitation.