1. The Mona Project: Studying effects of a grass invasion at Mona Island Reserve: Lead PI’s Elvia Meléndez-Ackerman 1,2 Denny Fernández 1,3 1 Institute for Tropical Ecosystem Studies – UPR-Río Piedras 2 Center for Applied Tropical Ecology and Conservation (CATEC) - UPR-Río Piedras 3 Wildlife Management Program, UPR-Humacao

2. Isla de Mona

3. Grass invasions and negative effects  Changes in disturbance regimes  Loss of biota (through competitive exclusion, habitat change)  Changes in ecosystem function

4. Cactus/ Cactus-Shrub Forest

5. Harrisia portoricensis  Endemic to Puerto Rico  Threatened species status since 1990 (USFW)  Threats: Habitat lost  Geographically restricted to Mona, Monito and Desecheo Island Presence of feral goats and pigs – USFW, 1990; Melendez-Ackerman et. Al. 2007 Presence of invasive grass species (Megathyrsus maximus). Studies Led by Julissa Rojas (PhD Student)

6. What is the performance of Harrisia portoricensis within the context of : Habitat modification by an invasive grass? Climate variability?

7.  6 permanent georeferenced plots established in Mona Island  769 tagged plants Seedlings <5cm Juveniles <50cm Adults >50cm Low shrub/cactus forest Megatyrsus maximum area Native platform forest High density of Harrisia Low density of Harrisia Martinuzzi et al. 2008

8. Grass Treatments No Grass v Partial Trimming (PT) Positive Control (PC) Complete Removal (PR) Large-Scale Experiment Design: 12 Plots Maintained monthly since January 2008 12 Micromet stations at each (PAR, Soil Temp, Soil Humidity) 1 Meterological Statioon (Air Temp, % Rel Humidity, Precipitation)

9. Areas invadidas de pasto: implicaciones para Harrisia Harrisia Área invadida de Megathrysus maximus

10. Grass biomass (+/- SE) per management treatment 10 sampling months Xavier Jaime et. al – UPR-Humacao ANOVAP Mes 0.3912 Treat. 0.0171

11. Soil mesofauna at grass invaded sites Moreno et. al. – UPR Río Piedras Lastra and Meléndez-Ackerman - UPR Rií Piedras -

12. Grass Effects - Posters

13. Additional projects:  Telemetry studies on feral goat movements and rock iguanas (Lopez MSc; Figuerola PhD)  Reproductive Ecology of Guaiacum sanctum (Fumero-Caban PhD)  Foraging behavior of polyginous Solenopsis invicta in Puerto Rico (Orengo MSc)  Long-term climatic trends and its relation to population dynamics in Lepanthes rupestris (Olaya, MSc.)  Cave arthropods’s diversity in the Northern Karst (Toro BSc)  Ecophysiology of the exotic tree Spathodea campanulata (UPR- Humacao, BSc.)  Extracting precipitation information from radar Satellite Imagery (UPR-Humacao BSc.)

14. Acknowledgements CATEC NSF-CREST NSF-Puerto Rico Alliance for Minority Participation NSF –Undergraduate Mentoring in Environmental Biology ESA-SEEDS Ford Motor Company AKKA-SEEDS Many collaborators and volunteers!!!