Methods to assess the impact of extraction of non-timber tropical forest products on plant populations

Thousands of plant and animal species in tropical regions provide a variety of non-timber products that are used by billions of people all over the world. Conservation and long term utilization of these species require that they be harvested on a sustainable basis. However, the extent to which non-timber forest products are exploited without adverse effects on natural populations is not known. There is in fact considerable evidence for non-sustainable harvest of non-timber products. We outline methods that may be used to assess the impact of harvest on population processes of the species that are being harvested. We present sampling protocols for rapid assessment as well as long term monitoring of populations. We briefly consider the limitations of these methods and suggest that the monitoring protocols we outline should be part of an overall management plan designed to extract and utilize non-timber tropical forest products on a long term basis.