Plant populations can respond to temporal environmental heterogeneity caused by natural disturbances, such as herbivory. Palm individuals of several species are preyed upon by mammals but the effects of such herbivory events on population dynamics remain poorly known. To evaluate the effects of environmental stochasticity on a Geonoma schottiana (Arecaceae) population, we surveyed annuallly 40 permanent 20 x 10-m plots in a riparian tropical forest over 5 y (2000-2004) and results were analysed using matrix models. The population growth rate (lambda) was in equilibrium during the study period and only one bad year was identified (2002-2003), which had a higher mortality of juvenile individuals due to herbivory. Additionally, the bad year had a higher mortality of reproductive individuals than the other periods. The stasis matrix elements of the late life stages were the vital rates with highest elasticities. The mortality of juvenile and reproductive individuals had a negative contribution to lambda in the bad year. Conversely, the growth of infant and juvenile individuals and the clonal growth of juveniles were the vital rates with highest contribution to stability maintenance of lambda in the bad year in a life-table response experiment. the palm population had a high individual density, high proportion of the initial life stages, clonal growth, high fertility, abundant seed bank and high seedling recruitment. Despite these traits, if stochastic herbivory events occur frequently over a long period of time the population will have a negative growth rate and the probability of local extinction will be very high.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.262151161