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

Vermeulen, Wessel Johannes (2009-03)

Thesis (PhD (Conservation Ecology and Entomology))--University of Stellenbosch, 2009.

Thesis

ENGLISH ABSTRACT: There is a growing appreciation of the importance of non-timber forest products (NTFPs) and the role they play in the socio-economic wellbeing of rural communities and other stakeholders. Harvest systems to ensure sustainable harvesting are largely still lacking and overutilisation is of growing concern worldwide. In this study the science needed to underwrite management for sustainable use of NTFPs was explored. This was done using case 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 florist industry, medicinal tree bark, and the corm (stem) of the geophyte Bulbine latifolia for medicinal use. The research approach enabled insight into the complexities of developing harvest systems for NTFPs, the input and expertise required to conduct applied research, and the variation in approach required for different products and plant growth forms. The study on R. adiantiformis showed that the adaptive management approach can be followed effectively with the development of harvest prescriptions for a species. Goalorientated, long-term monitoring, assessing harvest impact on the resource and natural fluctuations in population dynamics, are essential to verify that harvest prescriptions are sound and ecologically sustainable. However, if all relevant aspects are covered, the input required to develop and refine harvest systems through such monitoring may be extensive. Experimental stripping of medicinal tree bark showed that species respond differently to wounding, in terms of both bark regrowth and susceptibility to fungal and insect damage. The conceptual model and decision tree developed, demonstrated that tree response to wounding could be used effectively when choosing a management system for bark harvesting, and in informing prescriptions for strip harvesting. The proposed harvest system for the target species, as well as alternative options to meet the demand for bark can be successfully integrated 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 complex population dynamics and is abundant on the fynbos/forest ecotone, where it is associated with dry scrub forest communities. Although regeneration is sound, it has a slow rate of renewal in terms of corm diameter and length growth, limiting its harvest potential. The difference between ecotone and forest populations – in terms of population dynamics, plant demography and regeneration phenology – requires that consideration be given to differential harvest prescriptions for ecotone and forest populations. It was concluded that a simple generic process that provides for research to be focused on the relevant fields can be followed effectively with the development of harvest systems for NTFPs. However, sustainability also has a socio-economic and political dimension, further influenced by institutional arrangements. Considering the wide range of NTFPs used, socioeconomic circumstances and the dependence of rural communities on natural resources, a major challenge awaits forest managers in South Africa to develop harvest systems for sustainable use. Policy and decision makers need to appreciate the scientific skills and expertise, and financial resources required to realise this.

AFRIKAANSE OPSOMMING: Die belangrikheid van bosprodukte anders as hout en die rol wat dit in die sosio-ekonomiese welstand van landelike gemeenskappe en ander belanghebbendes kan speel, word toenemend besef. Oesstelsels om standhoudende benutting te verseker is grootliks afwesig en oorbenutting is wêreldwyd ’n toenemende bron van kommer. In hierdie studie word die wetenskaplike insette benodig om oesstelsels vir nie-houtbosprodukte te onderskryf, betrag. Dit is gedoen aan die hand van gevallestudies van drie bosprodukte wat uit natuurlike woud in die Suid-Kaap, Suid-Afrika, benut word, naamlik die blare van die varing Rumohra adiantiformis vir blommerangskikkings, medisinale boombas en die stam van die geofiet Bulbine latifolia vir medisinale doeleindes. Die navorsingsbenadering laat toe om insig te bekom in die kompleksiteit met die ontwikkeling van oesstelsels vir nie-houtbosprodukte, die insette en kundigheid benodig vir toegepaste navorsing, en die verskillende benaderings met verskillende bosprodukte en plantgroeivorms. Die studie oor R. adiantiformis dui aan dat ’n aanpasbare bestuursbenadering suksevol gevolg kan word met die ontwikkeling van oesvoorskrifte vir ’n spesie. Doelgerigte langtermynmonitering om die impak van inoesting op die bron en natuurlike fluktuasies in populasiedinamika te bepaal, is noodsaaklik om te kan aandui of oesvoorskrifte ekologiese standhoudendheid verseker. Die insette benodig om oesstelsels te ontwikkel en deur langtermynmonitering te verfyn, kan egter aansienlik wees. Eksperimentele basstroop dui aan dat boomspesies verskillend reageer op basverwydering in terme van bashergroei en vatbaarheid vir insek- en swamskade. ’n Konsepmodel en vloeidiagram vir besluitneming is ontwikkel en dui aan dat ’n boomspesie se reaksie op basverwydering effektief aangewend kan word in die keuse van ’n oesstelsel en die ontwikkeling van voorskrifte vir strookbenutting. Die voorgestelde oesstelsel vir die teikenspesies en ander alternatiewe om in die behoefte vir bas te voorsien, kan doeltreffend geintegreer word met die bestaande meervoudige-benutting woudbestuurstelsel in plek in die Suid-Kaap. Die studie oor die ekologie en dinamika van B. latifolia dui aan dat die soort goed verteenwoordig is in die fynbos/woud-ekotoon, dat dit geassosieer is met droë struikwoud, en ’n komplekse populasiedinamika het. Alhoewel dit goed verjong, het dit, gemeet aan stamdeursnee- en -lengtegroei, ’n lae groeitempo wat die benuttingspotensiaal van die spesie beperk. Die verskille tussen ekotoon- en woudpopulasies – in terme van populasiedinamika, demografie en reproduksiefenologie – vereis dat oorweging geskenk word aan verskillende oesvoorskrifte vir ekotoon- en woudpopulasies. ’n Eenvoudige, generiese proses wat verseker dat navorsing gefokus is op die toespaslike velde kan suksesvol gevolg word met die ontwikkeling van oesstelsels vir niehoutbosprodukte. Standhoudendheid het egter ook ’n sosio-ekonomiese en politieke komponent wat verder beinvloed word deur institusionele strukture. Inaggenome die wye verskeidenheid van nie-houtbosprodukte wat benut word, sosio-ekonomiese omstandighede en die afhanklikheid van landelike gemeenskappe van natuurlike hulpbronne, is die ontwikkeling van oesstelsels vir standhoudende benutting ’n groot uitdaging vir woudbestuursinstansies. Beleidmakers en besluitnemers moet ’n waardering ontwikkel vir die wetenskaplike kundigheid en kennis, en finansiële hulpbronne, wat benodig word om dit te bewerkstellig.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/3973
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