The fate of populations of Euterpe oleracea harvested for palm heart in Colombia

Palm heart is an important non-timber forest product obtained from various palm species in tropical forests. We studied the effect of four decades of palm heart extraction from the clonal palm Euterpe oleracea at the southern Pacific coast of Colombia. We monitored populations that had been subject to a range of harvest intensities and used measured vital rates (survival, growth, sexual and clonal reproduction) to construct population matrix models. We then used these models to simulate several harvest scenarios and to project the population dynamics for the next 50 years. Our projections suggest that the currently implemented intensive harvest regimes - which involve up to four harvests per year - result in dramatic demographic changes, primarily affecting seedlings and adults. In addition, current harvest regimes affect the future supply of palm heart, which is projected to drop sharply during the first years following harvest and fails to recover unless a number of stems are spared. Our simulations indicate that the most sustainable scenarios involve annual harvest between 50% and 75% of all harvestable stems, without any removal of small shoots from the clumps. Implementation of this regime must be accompanied by other management practices, including planning harvestable areas, marking the stems to be cut during subsequent harvests, assigning harvesters to specific areas, and leaving harvest residues as mulch around clumps. The degradation of populations of E. oleracea directly affects livelihoods of local people, by reducing cash income from palm heart sales and by reducing availability of palm fruits, a locally important food resource.