Wildflower Farming on the Agulhas Plain – Fynbos Management and Conservation
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Wildflower farming on the Agulhas Plain – fynbos management and conservation by Martina Treurnicht Thesis presented in partial fulfilment of the requirements for the degree Master of Science (Conservation Ecology) at Stellenbosch University Supervisor: Prof. Karen J. Esler Co-supervisor: Dr. Mirijam Gaertner Faculty of AgriSciences Department of Conservation Ecology and Entomology December 2010 Declaration By submitting this thesis/dissertation electronically, I declare that the entirety of the work contained therein is my own, original work, and that I have not previously in its entirety or in part submitted it for obtaining any qualification. Martina Treurnicht --------------------------- 04/10/2010 Copyright © 2010 University of Stellenbosch All rights reserved i Abstract The Agulhas Plain is a constituent of the Cape Floristic Region, internationally known as a global biodiversity hotspot. The species-rich Agulhas Plain consists mainly of fire-prone fynbos shrublands of which sandstone fynbos covers a significant surface area. This lowland region is characterised by mostly infertile soils yet has unique floristic complexity and contains a high amount of threatened lowland species. Natural vegetation on the Agulhas Plain has been prone to large scale land transformation activities, mainly attributed to the extent of alien plant invasions, urbanisation and agricultural expansion. Fynbos wildflower farming, specifically from natural vegetation, is an important economic activity and contributes to the region‟s agricultural sector. Farmers harvest large quantities of commercial fynbos species and supply these to the market in an attempt to sustain a livelihood. Certain wildflower farming practices (burning, ploughing and broadcast sowing) are applied to natural vegetation in an attempt to increase the abundance of commercial species (i.e. augmentation). Numerous farming practices are used in the industry and the application of these methods can be dynamic and divergent. Furthermore, the implementation of farming practices manifest as anthropogenically induced disturbance events and are a concern for conservation. Previous investigations suggest that farming practices could establish monocultures of commercial wildflower species by reducing species richness and plant diversity of wildflower vegetation. Although the impact of natural disturbance regimes (e.g. fire) and flower harvesting activities have been researched, the impact of farming practices on fynbos structure and composition remains largely unknown. This thesis reports on various aspects related to wildflower farming on the Agulhas Plain. Firstly, by administering a questionnaire, the extent and application of farming practices was investigated. Additionally, the opinion of wildflower farmers (referred to as landholders) about the impact of farming practices on wildflower populations was explored. Secondly, a vegetation survey aimed to assess the impact of farming practices on various structural (regeneration mode and growth form) and compositional attributes (plant family, dominant and rare species) of fynbos. Results from the questionnaire indicate that the application of farming methods are seasonally restricted, often used in varying combinations and relatively small in spatial extent. Furthermore, results show that wildflower farmers have an ecologically acceptable knowledge base and awareness of fynbos management and conservation. Secondly results, obtained from the vegetation survey, imply that natural vegetation subjected to particular farming practices differ from pristine fynbos vegetation by having both altered structural and compositional attributes. However, the impact of farming practices on rare species was less apparent. The conflict between commercial and conservation objectives are apparent from consultation with landholders. Nonetheless, landholders are optimistic about fynbos conservation and conservation can build upon these positive sentiments. Importantly, there is a need to communicate locally with landholders if a sustainable wildflower industry is a priority to stakeholders on the Agulhas Plain. Furthermore, fynbos ecosystems naturally entail complex ecological interactions. Wildflower farming practices reduce the ecological integrity (i.e. altered plant diversity, growth form and plant composition) of wildflower vegetation, at least at the local scale. These farming practices ultimately result both in distorted competitive interactions and disturbance regimes. Therefore, from a conservation perspective, the implementation of these farming practices (ploughing and broadcast sowing) should be cautioned against. ii Opsomming Die Agulhas-vlakte vorm deel van die Kaapse Blommeryk; „n gebied wat internasionale bekendheid verwerf het as „n biodiversiteits-brandpunt. Die spesieryke Agulhas-vlakte bestaan hoofsaaklik uit fynbosstruiklande wat geneig is tot veldbrande. Sandsteenfynbos beslaan „n beduidende oppervlak van die gebied (Agulhas-vlakte). Hierdie laagliggende area (Agulhas-vlakte) word meestal deur onvrugbare grondtipes gekenmerk maar beskik nogtans oor unieke fynbos kompleksiteit wat „n aantal bedreigde laagland spesies insluit. Natuurlike plantegroei op die Agulhas- vlakte is onderworpe aan grootskaalse grondgebruik transformasie; hoofsaaklik toe te skryf aan indringer plantegroei, verstedeliking en uitbreiding van landbou. Fynbos veldblomboerdery, spesifiek van natuurlike plantegroei, is „n belangrike ekonomiese aktiwiteit en lewer „n bydrae tot die Agulhas-vlakte se landbou sektor. Boere oes en lewer groot hoeveelhede kommersiële fynbos spesies aan die mark. Sekere veldblom-boerderypraktyke (brand, ploeg en saadstrooi) word ingespan op fynbosveld ten einde die opbrengs en afwisseling van kommersiële spesies te verhoog. „n Verskeidenheid boerderypraktyke word gevolg en die toepassing van hierdie boerderypraktyke is dinamies en uiteenlopend. Voorts manifesteer die implementering van hierdie boerderypraktyke as mensgemaakte versteurings wat kommerwekkend is vanuit „n bewaringsperspektief. Vorige ondersoeke dui moontlik daarop dat boerderypraktyke monokulture van kommersiële veldblomspesies kan vestig deur die veelheid van spesies en diversiteit van veldblomplantegroei te verminder. Ten spyte daarvan dat die impak van natuurlike versteuringsregimes (bv. vuur) en veldblompluk-aktiwiteite reeds nagevors is, bly die impak van veldblomboerderypraktyke op fynbosstruktuur en - samestelling grotendeels onbekend. Hierdie tesis doen verslag oor verskeie aspekte van veldblomboerdery op die Agulhas-vlakte. Eerstens, deur middel van „n vraelys, is die omvang en aanwending van verskillende boerderypraktyke nagevors. Verder is die menings van veldblomboere (na wie verwys word as grondeienaars) ondersoek met die klem op die impak van boerderypraktyke op veldblombevolkings. Tweedens, is „n plantegroei-opname met die doelwit om die impak van landboupraktyke op verskeie strukturele- (regenerasiemodus en groeivorm) en samestellende eienskappe (plantfamilie, dominante- en seldsame spesies) van fynbos vas te stel gedoen. Die resultate van die vraelys dui daarop dat die aanwending van boerderypraktyke seisoenaal beperk word, dikwels in wisselende kombinasies gebruik word en in ruimtelike omvang redelik klein is. Boonop toon die resultate dat veldblomboere oor „n ekologies-aanvaarbare kennisgrondslag en bewustheid van fynbosbestuur en –bewaring beskik. Tweedens, impliseer die resultate, vanuit die plantegroei-opname, dat fynbosveld wat onderwerp word aan sekere boerderypraktyke van natuurlike fynbosplantegroei verskil deurdat dit gewysigde strukturele- sowel as samestellende eienskappe toon. Die impak van die boerderypraktyke op seldsame spesies was egter minder waarneembaar. Die botsing tussen kommersiële- en bewaringsoogmerke blyk duidelik uit konsultasie met grondeienaars. Nietemin is die grondeienaars optimisties oor fynbosbewaring en bewaring kan op hierdie positiewe sentimente staatmaak en voortbou. Dit is belangrik om daarop te let dat dit noodsaaklik is om plaaslik met grondeienaars oorleg te pleeg indien „n volhoubare veldblomindustrie „n prioriteit vir belanghebbendes op die Agulhas-vlakte is. Verder, aangesien fynbos ekosisteme natuurlik komplekse ekologiese wisselwerkings behels, verminder veldblom- boerderypraktyke die ekologiese integriteit (m.a.w. gewysigde plantdiversiteit, groeivorm en plantsamestelling) van fynbosveld, ten minste op kleinskaal (plaaslik). Hierdie landboupraktyke het uiteindelik beide verwronge kompeterende wisselwerkinge asook versteuringsregimes tot gevolg. Vanuit „n bewaringsperspektief moet daar dus teen hierdie boerderypraktyke gewaarsku word. iii Dedication To my two lovely Oumas, Rita Leonhardt and Diedie Treurnicht. This is always how it is when I finish a poem. A great silence overcomes me, and I wonder why I ever thought to use language. Mevlana Rumi (1207-1273)1 1 With many thanks to Klara Mudge for sharing these words in a cabaret performance (Words, 2007) iv Acknowledgements I would like to thank the following people whose goodwill and expertise contributed significantly to the completion of this thesis: Karen Esler and Mirijam Gaertner who have been continually patient, supportive and whose expert guidance is much appreciated. The Gafney family (Nieuwepost) and the Van Dyk family (Nieuwedam) who were exceptionally kind to provide suitable study areas and, were both, friendly and welcoming throughout much of my field work. Sean Privett, Wilhelm Rabe, Roger Bailey, Edwina Marinus and the Compton Herbarium,, Anne