The sustainable harvesting of non-timber forest products from natural forests in the southern Cape, South Africa : development of harvest systems and management prescriptions

[摘要] ENGLISH ABSTRACT: There is a growing appreciation of the importance of non-timber forest products (NTFPs) andthe role they play in the socio-economic wellbeing of rural communities and otherstakeholders. Harvest systems to ensure sustainable harvesting are largely still lacking andoverutilisation is of growing concern worldwide. In this study the science needed tounderwrite management for sustainable use of NTFPs was explored. This was done usingcase studies of three different products harvested from natural forest in the southern Cape,South Africa viz. fern (Rumohra adiantiformis) fronds (leaves) as greenery in the floristindustry, medicinal tree bark, and the corm (stem) of the geophyte Bulbine latifolia formedicinal use. The research approach enabled insight into the complexities of developingharvest systems for NTFPs, the input and expertise required to conduct applied research, andthe variation in approach required for different products and plant growth forms.The study on R. adiantiformis showed that the adaptive management approach can befollowed effectively with the development of harvest prescriptions for a species. Goalorientated,long-term monitoring, assessing harvest impact on the resource and naturalfluctuations in population dynamics, are essential to verify that harvest prescriptions aresound and ecologically sustainable. However, if all relevant aspects are covered, the inputrequired to develop and refine harvest systems through such monitoring may be extensive.Experimental stripping of medicinal tree bark showed that species respond differently towounding, in terms of both bark regrowth and susceptibility to fungal and insect damage.The conceptual model and decision tree developed, demonstrated that tree response towounding could be used effectively when choosing a management system for bark harvesting,and in informing prescriptions for strip harvesting. The proposed harvest system for thetarget species, as well as alternative options to meet the demand for bark can be successfullyintegrated with the existing multiple-use forest management system in the southern Cape.The study of the ecology and dynamics of B. latifolia showed that the species has a complexpopulation dynamics and is abundant on the fynbos/forest ecotone, where it is associated withdry scrub forest communities. Although regeneration is sound, it has a slow rate of renewal interms of corm diameter and length growth, limiting its harvest potential. The differencebetween ecotone and forest populations – in terms of population dynamics, plant demographyand regeneration phenology – requires that consideration be given to differential harvestprescriptions for ecotone and forest populations.It was concluded that a simple generic process that provides for research to be focused on therelevant fields can be followed effectively with the development of harvest systems forNTFPs. However, sustainability also has a socio-economic and political dimension, furtherinfluenced by institutional arrangements. Considering the wide range of NTFPs used, socioeconomiccircumstances and the dependence of rural communities on natural resources, amajor challenge awaits forest managers in South Africa to develop harvest systems forsustainable use. Policy and decision makers need to appreciate the scientific skills andexpertise, and financial resources required to realise this.

[发布机构] Stellenbosch University