Ecological Effects of Non-Timber Forest Products Harvest and Trade: a Systematic Review

Abstract

Trade of non-timber forest products (NTFP) is a strategy that combines socioeconomic development with activities of low environmental impact. However, evidence suggests that harvesting these resources can produce negative ecological effects. This article identified the most common effects through a systematic literature review of empirical studies. Articles were previously evaluated against four criteria of inclusion, and were then classified according to the plant part harvested and the effects on 15 parameters at different levels of the biological organization. The results indicated that negative ecological effects are common, especially when harvesting barks and leaves in large volumes, although null and positive effects may also be observed. The parameters most frequently affected were population size; modifications in plant parts; age structure; probability of survival, and species richness. The evidence that NTFP harvest can cause significant ecological impacts calls for a need of monitoring and management systems.