Monday, November 13, 2006

Immediate Effect on Soil Biomass, Carbon and Nutrients after Hurricane Wilma in a Tropical Seasonal Forest.

Rodrigo Vargas and Michael F. Allen. Univ of California, Riverside, University Lab, Building Room 203, Center for Conservation Biology, Riverside, CA 92521

Soils were collected at a chronosequence of five seasonal forests (range 5-100 yrs) at the Yucatan Peninsula, Mexico one month before and one month after the occurrence of hurricane Wilma in October of 2005. Soils are sallow <10 cm and they are characterized by karstic features on limestone bedrock. We estimate that the study site sustained winds over 190 km/hr and >2m of precipitation between 12 and 24 hours. The hurricane removed 90% of the canopy coverage and produced a massive enrichment of organic matter on the soil. Pre-hurricane soil organic matter had a maximum of 62% in a mature forest and soil organic carbon accounts for over 75 MgC/ha in the shallow soils. We hypothesize that prior site history (forest age) might have different patters and limiting process of responses on soil biomass, carbon and nutrients after the hurricane. Nutrient limitations may occur because of the massive C:nutient ratio and possible nutrient leaching during the hurricane disturbance.