Recovery of the rain forest tree Vochysia ferruginea over 5 years following Hurricane Joan in Nicaragua: A preliminary population projection matrix

Initial observations of the effects of Hurricane Joan on southeastern Nicaraguan rain forest in 1988 indicated that, although damage to the forest was heavy, only one common tree species, Vochysia ferruginea, appeared to have declined so much as to be in danger of local extinction. We followed the population dynamics of this species over the next 5 years and developed a mathematical model of its recovery, using a stage-projection (Lefkovitch) matrix. The finite rate of natural increase, lambda, for the population was 1.156, indicating raid growth. Projection of the 1994 population gives a forecast of over ten-fold growth in the next 5 years, with a rapid approach to the stable stage distribution. Elasticities for survival, growth and fertility were respectively 64%, 28% and 7%. Applying Cochran and Ellner's (1992) methods, we found that most individuals in the population are under 10 years old, transitions between stages take only a few years, and mean age at first reproduction is just 7 years. Within-stage stable age distributions show decreasing peaks, decreasing skewness and decreasing kurtosis with increasing stage class. Forecasts of abundance after a few decades of growth at present rates result in impossibly high values, suggesting strongly that competition will reduce survival, growth and/or fertility rates in this species in the near future. (C) 1997 Elsevier Science B.V.