Coastal wetlands are ecosystems of great ecological and economic value. Their location within the transition zone between sea and land ecosystems contributes to their value, but also makes them vulnerable to the effects of global climate change, which includes high intensity hurricanes. The effects of these atmospheric phenomena on these ecosystems could be dramatic. Between September 5 and September 20, 2017, two powerful category 4 hurricanes passed nearby or directly hit the island of Puerto Rico. Hurricane Maria entered the island between Yabucoa and Maunabo municipalities, exactly over our study site. In this study, we show the effect of Hurricane Maria on the abiotic conditions (Temperature, Relative Humidity) of a fresh/brackish water wetland forest dominated by Annona glabra. Specifically, we determined how canopy defoliation affect the temperature and relative humidity within the A. glabra stand, and how the resprouting and canopy recovery could modified the post- hurricane conditions. To measure changes in abiotic conditions, we installed three HOBO automatic data sensors that registered temperature and relative humidity every 10 minutes at different localities within the forest and placed graduated falcon tubes at different levels above ground to determine the magnitude of the storm surge from the coastline into the freshwater wetland.
Results/Conclusions
Temperature and relative humidity data recorded pre-and post-hurricane showed that the daily pattern and mean temperature increased significantly after the hurricane (29.2 pre-hurricane, 32.2 post hurricane T=2.4, p<0.050). Relative humidity also varied significantly before and after hurricane Maria (T=2.19, p=0.03). In our study site, defoliation after hurricane Maria was total, and although most adult trees survived the observed changes in abiotic could be causing changes in biotic responses of the forest such as decomposition rates and seedling germination. Thus, the correlation of abiotic factors and rates of decomposition and seedling germination and survivorship will be important to help in the conservation and recuperation of this wetland site.