Hyphaene Petersiana Research Articles

Mass sterilization of a common palm species by elephants in Kruger National Park, South Africa

Chronic herbivory by elephants rarely eliminates any species of woody savanna plants because these plants are typically vigorous basal resprouters after damage by fire or herbivory. In some instances, resprouting after elephant herbivory even increases stem numbers per unit area compared to protected areas. It is thus difficult to know whether an area has been severely degraded by elephant herbivory or not because although trees may be severely reduced in size, they will still be present and may even be relatively dense. By using an elephant exclosure in the Kruger National Park, South Africa, we demonstrate that this resprouting ability masks the fact that entire populations of a widespread African palm, Hyphaene petersiana, are prevented from reaching sexual maturity by chronic elephant herbivory. Besides sterilizing these palms and thus preventing their evolution and seed dispersal, the absence of the palm fruits, flowers and tall stems has other negative biodiversity impacts on their associated fauna. We suggest that to determine sustainable elephant impacts on savanna plants, conservation managers also use the reproductive condition of savanna plants rather than their presence, height or stem density.

Elephant herbivory of knob‐thorn (Senegalia nigrescens) and ivory palm (Hyphaene petersiana) in Bwabwata National Park, Caprivi, Namibia: The role of ivory palm as a biotic refuge

AbstractAfrican elephants have major impacts on vegetation, particularly at high densities. Knob‐thorns (Senegalia nigrescens) are typically ring‐barked by elephant, and high levels of mortality are common at high elephant densities. Our study aimed to test whether ivory palm clusters (Hyphaene petersiana) form a biotic refuge for knob‐thorn against elephant herbivory. We measured the density, damage and mortality of knob‐thorns in sites differing according to ivory palm presence and elephant density, and thus, the probability of knob‐thorn encounter by elephants. The site with palms and low elephant density, had a high density of knob‐thorns, but lower proportions of damaged and dead trees, than sites without palms but with similar or higher elephant density. In the former, knob‐thorns were associated with palm clusters, particularly saplings and young adults. In this site, low proportions of damaged and dead knob‐thorns were recorded in palm clusters, compared with outside clusters, and to those in the other sites. Our study also showed that juvenile palms which protected knob‐thorns, suffered low mortality in contrast to subadult palms. We have no evidence but implicate elephants and suggest that in palm clusters, subadult palms are more accessible to elephants than knob‐thorns because of the different methods of utilisation.

Hyphaene petersiana dormancy and germination

Hyphaene petersiana is a naturally occurring palm tree in Zimbabwe. The tree provides an important supplementary source of income to the communities where it is found, with a high demand for foliage for making baskets and sap for wine making. Propagation is both by vegetative and sexual methods, however, sexual propagation is constrained by the inherent dormancy of the seeds. Breaking seed dormancy is also the first step towards developing a conservation programme for the tree. The effect of water soaking (for 12, 24 and 48 hours), chemical scarification (sulphuric acid for 10 minutes), de-husking (tegument removal), sand papering as well as chemical treatment (thiourea and potassium nitrate) were compared with untreated seeds (control). No germination was observed for seeds treated with sulphuric acid. Water soaking for 12 hours gave the highest germination (71.7%) although not significantly different to other treatments.

Influence of Fruits and Fermentation Time on Ethanol and Congener Production in Ombike Spirit in Namibia

Africa has a diversity of wild fruit trees, whose fruits are used to make traditional distilled drinks. Their beverage potential for specialty brandies has not yet been tapped. One such beverage is Ombike, which is produced traditionally in Namibia from various indigenous wild fruits from trees such as Ziziphus mucronata, Grewia spp. (e.g., G. flavescens, G. bicolor), Berchemia discolor, Diospyris mespiliformis, and Hyphaene petersiana. The methods of processing, the quantities of ingredients, the conditions such as temperature and duration of processing are often variable and not well documented. There are currently very few to none consistent and standardized products of known quality of Ombike that can compete in the formal marketplace. The processing method for these drinks is broadly the same as that of many distilled spirits imported into the country. However, currently the technology used for processing in Namibia is traditional and therefore not optimized. This study investigated the effect of duration of fermentation and distillation fractions on the yield of the beverage’s alcohol and congener content. The alcohol content of Ombike sold at informal markets in Namibia was also measured. The alcohol content of a number of household-made samples of Ombike was generally lower (6–30%) than what would be expected in distilled spirits (43%). Controlled distillation can yield Ombike with an alcohol content of over 90%. With improved optimization and standardization of the process for producing it, Ombike made using dry fruits of indigenous Namibia wild trees could become a commercial specialty fruit brandy.

Weaving a living: gender, craft, and sustainable resource use in Botswana

Abstract Botswana baskets are both an emblematic cultural symbol and a popular tourist souvenir, made by women from natural materials and reflecting gendered experiences of work, creativity, and resource use. The expansion of their production for sale over the past 30 years has often led to concerns about strain on the natural resources used for weaving, but more recently, the ways in which women talk about how they access these materials has changed. Rather than framing resources as scarce and under threat from poor harvesting practices, increasing numbers of women describe shifts in use practices that reflect growing awareness of the need to protect and cultivate plants such as hyphaene petersiana, or mokola palm. This change reflects the importance of rethinking what constitutes community-based natural resource management to include not only formalized trusts, but informal networks through which women harvest and use forest resources. It also highlights the insights of political ecology in considering the ways in which power impacts natural resource use, while emphasizing the need to expand notions of knowledge to become more inclusive and grounded. Key Words: Gender, political ecology, community-based conservation, Botswana, craft

A baseline classification of riparian woodland plant communities in the Okavango Delta, Botswana

In the Okavango Delta information on the riparian woodland vegetation community composition and distribution is generally lacking. Past studies in the Delta were mainly focused on the quantitative classification of seasonal floodplain herbaceous vegetation communities. The aim of this study was to determine riparian woodland vegetation communities in the Okavango Delta. Vegetation sampling was conducted in 20 m × 50 m randomly placed plots. The plots were placed along a gradient from the main water body to the drier fringe of the riparian zone. Plant species present in each plot were recorded with their estimated percentage cover using the Braun–Blanquet cover abundance scale. Hierarchical cluster analysis was used to determine vegetation communities. Indicator species analysis was used to calculate indicator values for species groups defined from the cluster analysis. Plant species and diversity were determined for each vegetation cluster. Multi-response permutation procedures (MRPP) were used to determine significance of differences between communities. The Kruskal–Wallis test was used to compare species diversity and richness between vegetation communities. Four vegetation communities were identified: Croton megalobotrys– Hyphaene petersiana, Vachellia erioloba–Diospyros lycioides, Syzygium cordatum–Phoenix reclinata and Garcinia livingstonei–Senegalia nigrescens. In this classification, the Syzygium cordatum–Phoenix reclinata and Garcinia livingstonei–Senegalia nigrescens plant communities are found in frequently flooded regions, whereas the Croton megalobotrys–Hyphaene petersiana and Vachellia erioloba–Diospyros lycioides are in occasionally flooded regions. Total number of species was highest in the Garcinia livingstonei–Senegalia nigrescens and lowest in the Syzygium cordatum–Phoenix reclinata vegetation communities. The MRPP showed that there was significant (p < 0.05) differences between vegetation communities. Species diversity and richness were significantly (p < 0.05) higher in the Garcinia livingstonei–Senegalia nigrescens vegetation community. This study provided an inventory of riparian woodland plant communities, which can be used as a vital monitoring tool of vegetation change in the Okavango Delta.

Ethnobotanical Study of Plants Used in the Management of HIV/AIDS-Related Diseases in Livingstone, Southern Province, Zambia.

Faced with critical shortages of staff, long queues, and stigma at public health facilities in Livingstone, Zambia, persons who suffer from HIV/AIDS-related diseases use medicinal plants to manage skin infections, diarrhoea, sexually transmitted infections, tuberculosis, cough, malaria, and oral infections. In all, 94 medicinal plant species were used to manage HIV/AIDS-related diseases. Most remedies are prepared from plants of various families such as Combretaceae, Euphorbiaceae, Fabaceae, and Lamiaceae. More than two-thirds of the plants (mostly leaves and roots) are utilized to treat two or more diseases related to HIV infection. Eighteen plants, namely, Achyranthes aspera L., Lannea discolor (Sond.) Engl., Hyphaene petersiana Klotzsch ex Mart., Asparagus racemosus Willd., Capparis tomentosa Lam., Cleome hirta Oliv., Garcinia livingstonei T. Anderson, Euclea divinorum Hiern, Bridelia cathartica G. Bertol., Acacia nilotica Delile, Piliostigma thonningii (Schumach.) Milne-Redh., Dichrostachys cinerea (L.) Wight and Arn., Abrus precatorius L., Hoslundia opposita Vahl., Clerodendrum capitatum (Willd.) Schumach., Ficus sycomorus L., Ximenia americana L., and Ziziphus mucronata Willd., were used to treat four or more disease conditions. About 31% of the plants in this study were administered as monotherapies. Multiuse medicinal plants may contain broad-spectrum antimicrobial agents. However, since widely used plants easily succumb to the threats of overharvesting, they need special protocols and guidelines for their genetic conservation. There is still need to confirm the antimicrobial efficacies, pharmacological parameters, cytotoxicity, and active chemical ingredients of the discovered plants.

Botswanan Palm Basketry among the Wounaan of Western Colombia: Lessons from an Intercontinental Technology Transfer

Traditional palm basketry of the Ba Yei and HaMbukushu people of the Okavango delta region in Botswana was introduced in the 1970s by a missionary to the Wounaan aborigines of western Colombia, who had a related weaving technique. The African technique was quickly assimilated by the Wounaan and enriched with shapes and decoration based on their own cultural patterns. The Chocoan palm Astrocaryum standleyanum, which the Wounaan used in their traditional baskets, replaced the African Hyphaene petersiana used in Botswana. The high quality of the new basketry led to a rapid success and turned Wounaan Astrocaryum baskets into an icon among Colombian handicrafts. Market pressure led to a severe depletion of the fiber-producing palm near Indian villages in the late twentieth century, as palms were felled by the hundreds to harvest the spear leaves. Educational campaigns and the introduction of an appropriate harvest tool have subsequently reduced the impact of leaf harvest, and A. standleyanum is now protected by the Wounaan. This case pinpoints the importance of a careful resource management assessment before introducing new market pressures on a traditional plant product. It is also a good example of positive results from a sustained campaign for appropriate resource management.

Ethnobotanical knowledge on indigenous fruits in Ohangwena and Oshikoto regions in Northern Namibia

BackgroundIndigenous communities in Namibia possess a rich indigenous knowledge expressed within many practices of these communities. Indigenous wild edible fruits are available along the Namibian 13 regions of which it forms a rich source of vitamins, fibres, minerals and a heterogeneous collection of bioactive compounds referred to as phytochemicals for indigenous people’s diet. The aim of this study was to record the different IKS practices on the indigenous fruit trees in Ohangwena and Oshikoto regions of Namibia.MethodsAn ethnobotanical survey was undertaken to collect information from local communities from 23-29 October 2011. Data was collected through the use of questionnaires and personal interviews during field trips in the Ohangwena and Oshikoto regions. A total of 65 respondents were interviewed; 54%; women, 38%; men and 8%; both in group interviews.ResultsThe majority of the people interviewed were in their thirty’s, with the youngest being 18 years old and the oldest being 98 years old. Forty three plant specimens were collected from the two regions; these specimens belong to 20 genera and 25 species. Regarding to the indigenous knowledge; 87%; of the respondents indicated that their knowledge on indigenous fruits was learnt mainly through their parent. Indigenous people’s perception on declining indigenous fruits revealed that 56.3%; of the respondents reported that indigenous fruits were declining. Only a 42.2%; indicated that the indigenous fruits populations are increasing. Regarding to the management practices to improve the production of these indigenous fruit trees; 38.6%; reported that there are some efforts on management practices; on the other hand 61.4%; reported there are no management practices on the indigenous fruit trees in their areas. Four species were found to be the most frequently used and mentioned fruits which need to be given high preference in terms of conservation are: Berchemia discolor, Hyphaene petersiana, Sclerocarya birrea and Diospyros mespiliformis. The following diseases and ailments have been reported to be treated by the indigenous fruit trees which include: toothache, diarrhoea, cough, tonsillitis, burns, skin allergy, stomach ache, snake bit, constipation, etc. 28%; of the respondents mentioned an ethno veterinary use(s) of these fruits, e.g. the use of the Ziziphus mucronata roots to treat diarrhoea in cattle, the bark of eembe (Berchemia discolor) to treat calf weakness.ConclusionsThe local communities in Oshikoto and Ohangwena regions have relatively good knowledge and practices regarding the indigenous fruit. This study enhances our understanding on the indigenous fruit in Namibia and their uses by local communities.

Impact of wine tapping on the population structure and regeneration of Hyphaene petersiana Klotzsch ex Mart. in northern Botswana.

Palms are tapped around the world as sources of sugars for fermentation. A comparison of tapped and untapped populations of Hyphaene petersiana Klotsch ex Mart. palm trees was conducted in northern Botswana. The objectives of the study were to: determine the densities, dominances, population structures and regeneration of natural palm stands. Social objectives of the study included assessment of preferred tree sizes for wine tapping, investigation of methods, frequency and processes involved in the wine tapping, and marketing of the tapped palm wine. The results revealed a significant difference in the mean total density of the species at the two study sites (Shorobe with 2,275 individuals/ha and Tubu with 1,402 individuals/ha). Total seed densities at Tubu (6,822/ha) and Shorobe (62/ha) were dramatically different. Mean total dominance (basal area) was significantly higher at Tubu than Shorobe where wine tapping is common. The species exhibited a pattern indicative of hampered population structures/regeneration at both sites. In Shorobe, the hampered regeneration can be attributed mainly to wine tapping associated with cutting down the trees. Palm wine tappers used destructive methods such as burning, felling, pruning and trimming the stem. The results revealed that the methods of wine tapping employed negatively impacted the population structure.

Climate change sensitivity of the African ivory nut palm, Hyphaene petersiana Klotzsch ex Mart. (Arecaceae) – a keystone species in SE Africa

Africa is the most vulnerable continent to future climate change. Profound changes are projected for southwestern Africa with increased drying, notably with delayed onset of the rainy season in September-November, and temperature increases in all seasons. The projected climate changes combined with land-use changes are thought to constitute the main threats to biodiversity in the 21st century. To be able to predict the potential impact on biodiversity, it is crucial to achieve a better insight into the controls of contemporary species ranges. Using species distribution modeling, we assessed the climate sensitivity of the key-stone palm species Hyphaene petersiana (African ivory nut palm) in southern Africa. We tested the relative roles of climate vs. non-climatic range-controls and found that climate had a clear effect on the range of H. petersiana and that especially water-related variables (annual precipitation and precipitation driest quarter) were of high importance. Nevertheless, latitude was the overall most dominant variable, reflecting spatial constraints on the continental-scale distribution. Of the remaining non-climatic factors, soil type and human influence were as important as the climatic factors. A future decrease in annual precipitation below 400 mm and hydrological changes towards drier conditions could cause a dramatic decline in H. petersiana populations, while the influence of temperature changes is less clear. The ongoing, unsustainable utilization pressures on this palm species by humans and livestock are likely to exacerbate the negative effect of future climate changes on its populations, especially, given the expected human population increase in Africa.

Profiling of Phytosterols, Tocopherols and Tocotrienols in Selected Seed Oils from Botswana by GC–MS and HPLC

AbstractThe phytosterol, tocopherol, and tocotrienol profiles for mkukubuyo, Sterculia africana, manketti, Ricinodendron rautanenni, mokolwane, Hyphaene petersiana, morama, Tylosema esculentum, and moretologa‐kgomo, Ximenia caffra, seed oils from Botswana have been determined. Normal‐phase HPLC analysis of the unsaponifiable matter showed that among the selected oils, the most abundant tocopherol and tocotrienol were γ‐tocopherol (2232.99 μg/g) and γ‐tocotrienol (246.19 μg/g), detected in manketti and mkukubuyo, respectively. Mokolwane oil, however, contained the largest total tocotrienol (258.47 μg/g). Total tocol contents found in manketti, mokolwane, mkukubuyo, morama, and moretologa‐kgomo oils were 2238.60, 262.40, 246.20, 199.10, and 128.0 μg/g, respectively. GC–MS determination of the relative percentage composition of phytosterols showed 4‐desmethylsterols as the most abundant phytosterols in the oils, by occurring up to 90% in moretologa‐kgomo, mkukubuyo, and manketti seed oils, with β‐sitosterol being the most abundant. Mokolwane seed oil contained the largest percentage composition of 4,4‐dimethylsterols (45.93%). Besides 4‐desmethylsterols (75%), morama oil also contained significant amounts of 4,4‐dimethylsterols and 4‐monomethylsterols (15.72% total). GC–MS determination of the absolute amounts of 4‐desmethylsterols, after SPE fractionation of the unsaponifiable matter, confirmed that β‐sitosterol was the most abundant phytosterol in the test seed oils, with manketti seed oil being the richest source (1326.74 μg/g). The analysis showed total 4‐desmethylsterols content as 1617.41, 1291.88, 861.47, 149.15, and 109.11 μg/g for manketti, mokolwane, mkukubuyo, morama, and moretologa‐kgomo seed oils, respectively.

NMR, GC–MS and ESI‐FTICR‐MS Profiling of Fatty Acids and Triacylglycerols in Some Botswana Seed Oils

AbstractIn the search for non‐traditional seed oils, physicochemical parameters, fatty acid (FA) and triacylglycerol (TAG) profiles for five Botswana seed oils, obtained by Soxhlet extraction, were determined. GC–MS and 1H‐NMR analyses showed the FA profiles for mkukubuyo, Sterculia africana, and manketti, Ricinodendron rautanenii, seed oils dominated by linoleic and oleic acids, 26.1, 16.7 and 51.9, 24.4%, respectively, with S. africana containing significant amounts of cyclic FAs (19.9%). Mokolwane, Hyphaene petersiana, seed oil was typically lauric; 12:0 and 14:0 acids were 25.9 and 13.4%, respectively. Morama, Tylosema esculentum, seed oil resembled olive oil; 18:1 (47.3%) and 18:2 (23.4%) acids dominated. Moretologa‐kgomo, Ximenia caffra, seed oil had 45.8% of 18:1 FA, plus significant amounts of very long chain FAs: 26:1 (5.8%), 28:1 (13.9%), 30:1 (3.9%), and acetylenic acids, 9a‐18:1 (1.5%) and 9a, 11t‐18:2 (16.0%). TAG classes and regiochemistry were determined with ESI‐FTICR‐MS, and 13C‐NMR spectra, respectively. Morama showed seven major TAG classes with C54:4 and C54:3 dominating; mokolwane had 16 major classes with C32:0, C38:0 and C42:2 dominating; manketti had 11 major classes with C54:7, C54:6 and C54:4 dominating; mkukubuyo had 12 major classes with C52:4, C52:3 and C54:4 dominating; moretologa‐kgomo had 30 major TAG classes with C64:5, C64:3 and C62:3 dominating. Saturated FAs were generally distributed over the sn‐1(3) position for morama, manketti, and moretologa‐kgomo but at the sn‐2 position for mokolwane and mkukubuyo. These findings indicate that morama and manketti seed oils can be developed for food uses, whilst moretologa‐kgomo and mkukubuyo seed oils only for nonfood uses.

Palaeoecological significance of palms at Olduvai Gorge, Tanzania, based on phytolith remains

Palms are among the most abundant, diverse and economically important families of plants in tropical and subtropical regions of the world; their number and diversity make them an important part of the ecosystem. Phytoliths are abundantly produced in palms, mainly the spheroid echinate type and, although their number decreases notably after their deposition in soils, they remain stable for long periods of time. Palm phytoliths were recovered from sediments at HWKEE, on the eastern palaeolake margin of the Olduvai basin during Lowermost Bed II (between Tuffs IF and IIA, 1.795–1.71 Ma). Their abundance in trench 107 (the only freshwater source recognised to date) occurs in three stratigraphically consecutive layers, the first one located immediately above the incision layer (40 cm above Tuff IF). Above these samples there are no palm phytoliths in the fossil record. The identification of the type of palms represented will be useful for determining the landscape distribution and nature of hominin activities along the lake margin and alluvial fan of the central Olduvai Basin. Here we use morphometric analysis of spheroid echinate phytoliths from fossil and modern palms ( Phoenix reclinata and Hyphaene petersiana) and their corresponding soils to determine if the differences are significant and can be confidently applied to the fossil samples. Fossil and modern soil samples were found to be very similar to each other but the spheroid echinates from the fossil soils were bigger than the modern soil samples. Either the palms from the samples were different or there is a strong bias towards preserving phytoliths from the smaller end of the range. If this is the case then the implication would be that the fossil samples are the leaves and inflorescences of Phoenix reclinata. A wider variety of modern palms needs to be analysed.

IMPACTS OF LEAF HARVESTING AND SAP TAPPING ON THE IVORY PALM (HYPHAENE PETERSIANA) IN SOUTH EASTERN ZIMBABWE

ABSTRACT People living in the marginal areas of Southern Africa have relied on palm resources for subsistence for centuries and yet little is known about the impacts of their harvesting activities. This work aimed at providing data on the impacts of two forms of traditional exploitation, leaf harvesting and sap tapping on the palm, Hyphaene petersiana. Three experiments were carried out in southeastern Zimbabwe • leaf harvesting to evaluate its impacts on new leaf production and the availability of harvestable material, • sap tapping to assess amounts produced, and • evaluating the regeneration potential of tapped ramets. Findings from this research were that: ∘ leaf harvesting reduced new leaf production, growth and the availability of harvestable material; ∘ sap tapping did not necessarily kill the palm but the extent of meristem removal determined the likelihood and mode of regeneration. We conclude that leaf harvesting and sap tapping activities influence the subsequent development of the palm Hyphaene petersiana and that efforts should be made to adopt harvesting and tapping strategies that will ensure reliable raw material supply for the craft industry which is sustaining many lives in Southern Africa.

AN ASSESSMENT OF THE SUSTAINABILITY OF THE UTILISATION OF SAVANNA PRODUCTS IN BOTSWANA

ABSTRACT The majority of Botswana's population use a wide range of savanna products for food, fodder, medicine, fuel, building, utensils and income. The poorest households in both rural and urban areas, are most reliant on their consumption and trade. This study sought an holistic insight into practices and policies jeopardizing the sustainable utilization of these products. A comparative review of literature and information gleaned from key informants revealed that the basket making industry around Maun has already threatened the sustainability of Hyphaene petersiana, Berchemia discolor and Euclea divinorum. Overharvesting of Harpagophytum spp., ‘Khalimela’ and ‘Lulula’ for traditional medicinal trade purposes poses a significant threat to their sustainability. Damage caused by Phane poachers poses a significant threat to Colophospermum mopane. Bush encroachment has become increasingly prevalent over vast tracts of Botswana's savannas. While it reduces the potential range and supply of savanna products in the particular areas where it is taking place, it does not exert a significant detrimental influence on these products over larger spatial and temporal scales. The most widespread threat to the sustainability of savanna products nationally is too frequent fires. In the southeast portion of the country the sustainability of savanna products is threatened by a combination of overgrazing, excessive fuel wood harvesting, clearance for cultivation and expansion of infrastructure. In the northeast damage by an overpopulation of elephants poses the most severe threat. Despite the increasing demand for savanna products and the large number of factors serving to decrease their range and availability, their potential supply at the national level is far greater than the demand for them. The employment opportunities created by disparities in the spatial distribution of supply and demand are already playing a significant role in national poverty alleviation. The campaign to reduce the frequency of veld fires, the redundancy of the requirement to clear land to avoid forfeiture, the removal of subsidies to commercial beef farmers, and the provision for local communities to have increased responsibility for managing and access to forest resources in the New Forest Policy and the pending associated legislation may well counterbalance the magnitude of these threats in the future.

ILALA PALM (HYPHAENE PETERSIANA) USE IN SOUTHERN ZIMBABWE: SOCIAL AND ECOLOGICAL FACTORS INFLUENCING SUSTAINABILITY

ABSTRACT A dynamic ecological model, calibrated with field data from the communal lands of southern Zimbabwe where Shangaan and Ndebele people live, shows the ilala palm, Hyphaene petersiana, to be resilient to a wide range of harvesting regimes. The degree of use determines the plant population structure but not the palm's continued existence. Ilala palm sap for wine and leaves for crafts provide an important source of income at the village level. Shangaan households generally regulated palm use, with the manual workers usually being Ndebele. Despite the designation of the region as a “communal area” there are clearly social conventions limiting access to resources. The use of the plant for sap is more closely regulated than its use for leaves. Leaf harvests appear less ecologically destructive than tapping for sap. Although social rules reduce harvesting, the ecology of the palm is such that intensive harvesting may actually increase the available products by changing the ilala palms into more accessible and useful growth forms.

The effects of utilization by people and livestock on Hyphaene petersiana (Arecaceae) basketry resources in the palm savanna of North-Central Namibia

Basketry production is an important informal sector activity in the palm savanna of north-central Namibia, particularly for women. This study assesses the comparative impact of utilization by basket makers and browsing livestock in areas of different human and livestock population pressures on the source of weaving fibre, leaves from juvenile individuals of the vegetable ivory palm,Hyphaene petersiana. Mature individuals of this species are an important source of edible fruit. Destructive uses of mature individuals such as tapping for palm wine and the cutting of stems for construction purposes are also practised, even though they are forbidden by customary law. Unlike other centres of basket production in southern Africa, the level of leaf utilization for basketry is low and there is potential for greater use of this resource. Despite the unpalatability of this species, a cause for concern, however, is the intensity of browsing by domestic livestock on young palms, which may affect the future structure and viability of the palm population in north-central Namibia. This predicted degradation of a multiple-use species such asH. petersiana represents the gradual erosion of an important buffer against rural poverty, loss of income and reduction in food security.

The impact of utilization of palm products on the population structure of the vegetable ivory palm (Hyphaene petersiana, arecaceae) in North-Central Namibia

Indigenous trees fulfil many subsistence and economic needs in north-central Namibia.Hyphaene petersiana provides a range of products which contribute to most aspects of people’s livelihoods. Of particular importance is its income-generating capacity through the use of palm leaves for basket production and the sale of liquor distilled from the fruits. This study investigates the population structure ofHyphaene petersiana in two areas of different human and livestock densities. Data were recorded for height class distribution, basal diameter of mature, stemmed individuals and sex ratios. These parameters of population structure indicate a reduction in the recruitment of mature palms and an increase in single-stemmed, vegetatively reproduced palm suckers of the smallest size class (0.5 m). This trend is more pronounced in the site with greater human and livestock population densities. It appears to be related to high recorded levels of browsing by livestock of juvenile, unstemmed palms, despite the unpalatability of palm leaves. This acts to prevent recruitment into larger size classes and increase the compensatory growth of palm suckers, the latter being enhanced due to reduced competition through the prior removal by grazing animals of grasses and other herbaceous species. Accompanying this heavy pressure on juvenile palms are destructive uses of mature, stemmed palms, including their felling for construction purposes and tapping for palm wine. With regional human population increase, exacerbated by a recent trend to privatise land and raise pressure on remaining communal resources, it is possible that these destructive uses of mature palms will increase to unsustainable levels. Concern is thus expressed in this study regarding the long-term viability ofHyphaene petersiana populatiops in this area.