BIOMASS AND NUTRIENT CONTENT OF THE BISLEY EXPERIMENTAL WATERSHEDS, LUQUILLO-EXPERIMENTAL-FOREST, PUERTO-RICO, BEFORE AND AFTER HURRICANE-HUGO, 1989

The biomass and nutrient content of two steepland watersheds were esti mated using allometric equations and nutrient concentrations derived f rom a subsample of the vegetation. Prior to the passage of Hurricane H ugo in September 1989, the watersheds had a total vegetative biomass o f 301 tons/ha, 75 percent of which was aboveground. The total nutrient content of this vegetation was 907, 49, 644, 653, and 192 kg/ha for N , P, K, Ca, and Mg, respectively and varied with topographic setting. Concentrations per unit dry weight of P (0.16), K (2.49), Ca (2.13), a nd Mg (0.62) in aboveground vegetation were similar to other steepland tropical forests, while the concentration of N (2.9) was greater. Fol lowing the passage of Hurricane Hugo, the standing aboveground biomass was reduced to 113 t/ha and the aboveground nutrient content of the f orest was reduced 45 to 48 percent.