Short‐Term Disappearance of Foliar Litter in Three Species Before and After a Hurricane1

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Abstract
Litter disappearance was examined before (1989) and after (1990) Hurricane Hugo in the Luquillo Experimental Forest, Puerto Rico using mesh litterbags containing abscisedCyrilla racemiflontorDacryodes excelsaleaves or freshPrestoea montanaleaves. Biomass and nitrogen dynamics were compared among: (i) species; (ii) mid‐ and high elevation forest types; (iii) riparian and upland sites; and (iv) pre‐ and post‐hurricane disturbed environments. Biomass disappearance was compared using multiple regression and negative exponential models in which the slopes were estimates of the decomposition rates subsequent to apparent leaching losses and the y‐intercepts were indices of initial mass losses (leaching).Cyrilla racemifloraleaves with low nitrogen (0.39%) and high lignin (22.1%) content decayed at a low rate and immobilized available nitrogen.Dacryodes excelsaleaves had moderate nitrogen (0.67%) and lignin (16.6%) content, decayed at moderate rates, and maintained the initial nitrogen mass.Prestoea montanafoliage had high nitrogen (1.76%) and moderate lignin (16.7%) content and rapidly lost both mass and nitrogen. There were no significant differences in litter disappearance and nitrogen dynamics among forest types and slope positions. Initial mass loss ofC. racemifloraleaves was lower in 1990 but the subsequent decomposition rate did not change. Initial mass losses and the overall decomposition rates were lower in 1990 than in 1989 forDacryodes excelsa. Dacryodes excelsaandC. racemifloralitter immobilized nitrogen in 1990 but released 10‐15 percent of their initial nitrogen in 1989, whereasP. montanareleased nitrogen in both years (25‐40%). Observed differences in litter disappearance rates between years may have been due to differences in the timing of precipitation. Foliar litter inputs during post‐hurricane recovery of vegetation in Puerto Rico may serve to immobilize and conserve site nitrogen.