Department of Biological Sciences

Permanent URI for this community

https://univendspace.univen.ac.za/handle/11602/1925

Browse

Now showing 1 - 20 of 108

Open Access
3D Cranial Morphometry, Sensory Ecology and Climate Change in African Rodents
(2019-05-15) Nengovhela, Aluwani; Taylor,, Peter; Braga, Jose
The order Rodentia is the most speciose group of mammals with muroids being the most diverse superfamily. Since they are represented in arboreal, semiaquatic, subterranean and terrestrial niches, rodents may exhibit morphological traits reflecting their adaptations to such diverse environments. This thesis focuses on the morphology of the endocranium, auditory bulla and cochlea in three tribes (Otomyini, Taterillini and Gerbillini) representing 10 species of African rodents, concentrating on their variability, function and adaptability, using micro-CT imaging and 3D shape comparative methods. Additionally, variations in cranial size were also studied in respective of global warming and climatic variables. Morphological changes/variations are a result of environmental change, therefore each chapter in this study details the effect of environmental change (in space and time) on different morphological traits i.e. general cranial size (chapter 2), cochlea and auditory bulla (chapter 3) and endocranial size and shape (chapter 4). With chapter 2 dealing specifically with climate change in its strict sense and the remaining two chapters looking at different environmental gradients. Chapter 2 tests the applicability of the “third universal response to warming” (i.e. declining body size) and the Resource Rule in two murid subfamilies, Murinae and Gerbillinae. The study shows that the third response is not as universal as only one species conformed to this response. Further, food availability (Resource Rule) was shown to be the more important factor correlated with body size variations in rodent species than Bergmann’s Rule. Chapter 3 looks at the auditory bulla and cochlea, the morphological traits that play a role in hearing capabilities of rodents. I found, with some exceptions, that bulla and cochlea modifications between species could be explained by environment, phylogeny and/or allometry. In addition, I concluded that true desert adapted laminate-toothed rats and gerbils use both bulla and associated cochlea hypertrophy. Chapter 4 shows larger brain size in Taterillini and two species of Otomyini, with life histories and environment being the most probably factors responsible for xiv this. Using a novel method of diffeomorphism (deformation models), there was more variation in endocranial morphology between the gerbils and laminate-toothed rats than within them with olfactory bulb, paraflocculi, and posterior ventral cortex showing the most variability. Overall, this thesis shows that variations in the morphological traits studied are strongly influenced by the environment and function.
Embargo
An analysis of exposure and slope gradient impact on tree layer profile of Maroelakop vegetation in Nylsvley Nature Reserve, Limpopo Province, South Africa
(2024-09-06) Mavhila, Tendani; Tshisikhawe, M. P.; Magwede, K.
Since the 1850s, plant ecologists have been eager to investigate challenges in vegetation communities that are related to slope. The aspect of the slope is crucial in terms of the diversity and distribution of plants. This research was conducted on Maroelakop Mountain within Nylsvley Nature Reserve located in Mookgopong, Limpopo Province. The investigation aimed to assess and contrast the vegetation composition on the north-facing slope with that of the south-facing slope. The specific goals included ascertaining the density and frequency of dominant tree species on each slope, calculating the importance value indices of trees on both slope gradients and analyzing the population structure of the slope gradient. Point Centred Quarter (PCQ) was used in data collection. Shannon-Weiner diversity index, Simpson diversity index, and Evenness index were used to measure plant species diversity. In this study, a total of 600 trees were discovered and identified by their botanical names. The data represented 21 plant species in 17 genera and 12 families. The tree layer of the north-facing slope was dominated by Diplorhynchus condylocarpon, whereas that on the south-facing slope was dominated by Burkea africana. Both tree species had high-importance value indices. Shannon diversity index of 2.20 was obtained for the North-facing downslope, whereas the South-facing downslope had 1.74. The average Simpson diversity index for the North-facing slope was 0.82 and South-facing slope 0.77. The average Evenness index for the North-facing slope was 0.93 and, on the South-facing slope 0.81. This study concluded that Diplorhynchus condylocarpon is the most prevalent species within Maroelakop Mountain in the Nylsvley Nature Reserve.
Open Access
Animal taxa contrast in their scale-dependent responses to land use change in rural Africa
(2018-05-08) Foord, Stefan Hendrik; Swanepoel, Lourens Hendrik; Evans, Steven Wiiliams; Schoeman, Colin Stephan; Erasmus, Barend Frederik N.; Schoeman, M. Corrie; Keith, Martin; Smith, Alain; Mauda, Evans Vusani; Maree, Naudene; Nembudani, Nkhumeleni; Dippenaar-Schoeman, Anna Sophia; Munyai, Thinandavha Caswell; Taylor, Peter John
Human-dominated landscapes comprise the bulk of the world's terrestrial surface and Africa is predicted to experience the largest relative increase over the next century. A multi-scale approach is required to identify processes that maintain diversity in these landscapes. Here we identify scales at which animal diversity responds by partitioning regional diversity in a rural African agro-ecosystem between one temporal and four spatial scales. Human land use practices are the main driver of diversity in all seven animal assemblages considered, with medium sized mammals and birds most affected. Even the least affected taxa, bats and non-volant small mammals (rodents), responded with increased abundance in settlements and agricultural sites respectively. Regional turnover was important to invertebrate taxa and their response to human land use was intermediate between that of the vertebrate extremes. Local scale (< 300 m) heterogeneity was the next most important level for all taxa, highlighting the importance of fine scale processes for the maintenance of biodiversity. Identifying the triggers of these changes within the context of functional landscapes would provide the context for the long-term sustainability of these rapidly changing landscapes
Open Access
Ant and spider diversity in a rural landscape of the Vhembe Biosphere, South Africa
(2017-09-18) Mauda, Evans Vusani; Foord, S. H.; Munyai, T. C.
See the attached abstract below
Open Access
Assessing species richness patterns and conservation threats (due to overharvesting and climate change) in South African Cycads, with emphasis on a population of Encephalartos tranvenosus Stapf and Burt Davy from the Soutpansberg Mountain, Limpopo Province
(2018-05-18) Bamigboye, Samuel Oloruntoba; Tshisikhawe, Peter Milingoni; Taylor, Peter John
Cycads are regarded as the oldest living seed plants on earth and they have existed for about 300 million years. Ever since the awareness of the existence of this plant group, they have been facing high extinction risk. Currently they are referred to as the most threatened plant group in the world. Many ecological and anthropological forces are promoting extinction crisis of this taxonomic group. Africa is one of the centres of diversity of this plant group with 70% of the total number of the taxa in this group in Africa found in South Africa. Also South Africa is one of the global hotspots for cycads and it contains the third largest number of cycads after Australia and Mexico. Studies have revealed that there have been high threats and extinction risks among the cycad taxa in South Africa. The Soutpansberg Mountain is a major biodiversity hotspot in Limpopo Province in South Africa with high level of flora and fauna taxa. About 3000 vascular plants species are represented on this mountain. Biodiversity on this mountain has been under threat in recent times and there is need to investigate how cycads are facing risk on this mountain. The main focus of this study is to look at the extinction pattern in South African cycads and cycads endemic to Soupandberg Mountain in Limpopo Province in South Africa. v The first objective evaluated all African cycads over a decade using IUCN red list. Data from IUCN 2014 version was used to calculate the percentages of African cycads in each IUCN categories. The results were compared with those presented by Donaldson 2003. They showed that there have been significant decline and increase in extinction of African cycads over this period. It was also discovered that majority of this extinction crisis were trending in South Africa. The second objective used the IUCN red list to evaluate extinction pattern in South African cycads. The percentages of IUCN threat categories of South African cycads was calculated using IUCN red list. ArcGIS was used to construct distribution map for threatened and extinct South African cycads. The study revealed that the proportion of historically Extinct and Critically Endangered cycads is higher in Limpopo, KwaZulu-Natal and Mpumalanga than the rest of the provinces in South Africa. The third objective of this research investigated extinction pattern of Encephalartos transvenosus Stapf & Burtt Davy (Modjadji cycad) on Soutpansberg Mountain. Indigenous knowledge and population ecology approaches were used to determine current threats Modjadji cycads are facing on Soutpansberg Mountain. The results showed that anthropogenic activities have caused a substantial decline of one important unprotected population of this species on Soutpansberg Mountain.
Open Access
Assessment of androstachys johnsonii prain, stem utilization in Matshena Village, Mutale Local Municipality, Limpopo Province
(2016-02-02) Bakali, Mulalo; Tshisikhawe, M. P.; Ligavha-Mbelengwa, M. H.
Embargo
Assessment of nutraceutical attributes of selected wild edible fruit plants used by Vhavenda people of the Thulamela Local Municipality
(2024-09-06) Nephawe, Rinae Lucy; Mokganya, M. G.; Madala, N. E.
Wild edible fruit plants are highly valued in many remote rural areas, where they play a significant role in fulfilling the sociocultural and livelihood needs of people. Many of these plants are harvested by local communities to augment and diversify their diets as well as to promote local food security. The decline in the use of wild edible fruit plants may be due to a lack of knowledge of their nutritional value, their potential for income generation, and medicinal and cultural uses. This study focused on the documentation of utilisation, conservation, and nutraceutical composition of the wild edible fruit plants of the Thulamela Local Municipality. Information on wild edible fruit plants was gathered through semistructured interviews, fieldwork, and a literature review. A total of 39 wild edible fruit plants of 22 botanical families recorded during the study were used as food, beverage, and additionally as medicine. The number of wild edible fruit plants with medicinal properties was 39 whereas those used to make beverages were 9. Wild edible fruit plants of Thulamela municipality were experiencing challenges due to human activities resulting in declining, endangered, or even extinct. Results of this study also showed the use of wild edible fruit plants as firewood because 10 out of 39 were mentioned for this use. In this study the UHPLC-qTOF-MS/MS-based in source collision induced dissociation method was utilized to generate fragmentation data to assist in the differentiation of closely related isomers. Wild edible fruit plants have been used for centuries in traditional medicine and for nutritional purposes. Strychnos species has not yet been fully decoded, and due to the inherent complexity of plant metabolomes, the characterization of Strychnos photochemistry remains challenging. Thus, in this study, we propose the use of molecular networking to unravel the families using the metabolome analysis of two Strychnos species (Strychnos pungens and Strychnos spinosa) and highlight the relevance of molecular networking in exploring the chemotaxonomy of plants. This allows visualization of chemical classes and the variety of substructures within the molecular families.
Embargo
Bioaccumulation and the human health risk of p,p'-DDT, p,p'-DDD, p,p'-DDE in freshwater fish species from the north-eastern Limpopo River valley, Vhembe District, Limpopo Province, South Africa
(2024-09-06) Mphephu, Sherron; Barnhoorn, I. E. J.; Bornmann, M. S.
Dichloro-diphenyl-trichloroethane (DDT) has been used globally as an agricultural pesticide since the early 1940s, and both the United States and Canada banned its use in 1972. DDT is still used in the malaria-endemic region of South Africa for vector control through indoor residual spraying (IRS). Studies have reported a link between DDT exposure and prostate cancer risk and/or aggressive disease presentation in Italy, Canada, and the United States. Epidemiological analysis of men with prostate cancer (PCa) in South Africa showed an increased PCa risk in Vhavenda people, the predominant population of Vhembe. The Vhembe District municipality falls in the malaria-endemic region, where DDT is used for vector control. The region of interest is fed by three major tributaries of the Limpopo River, which provide communities with agriculture, washing/bathing and portable water as well food (fish). Therefore, environmental levels of p,p-DDT, p,p-dichlorodiphenyldichloroethane (DDD) and p,p- dichlorodiphenyldichloroethylene (DDE) were measured before and after of the 2022 malaria high-transmission period (HTP), through sampling fish, from the Mutale and Mutshindudi rivers, and Thathe Vondo Dam. Fishes were bought from fishermen at the Thathe Vondo Dam and along the Mutale and Mutshindudi rivers. The fish's edible part (muscle), one piece raw and one piece cooked was tested for DDTs. Fish from the Mutshundudi River had higher DDT residuals than all other sites before the IRS. None of the DDTs were present after the yearly IRS. Daily exposure of DDTs for consumers was estimated by comparing estimated daily intake (EDI) with different criteria. The results revealed that the EDIs in our study were all lower than those criteria. Target hazard quotient (THQ) and risk ratio (R) were used to evaluate non-carcinogenic (toxic) and carcinogenic risks. There was no carcinogenic or toxic risk for humans consuming fish from the Mutale and Mutshindudi rivers and Thathe Vondo Dam. This indicates that DDT, DDD, and DDE in fish are not affecting the PCa burden in the Vhavenda men living in remote communities.
Open Access
Bioactivity and chromatographic profiles of the selected medicinal plants against candida albicans
(2015-07-17) Mulaudzi, Takalani Millicent; Masevhe, N. A; Mojapelo, P. E. L
Open Access
Comparative in vitro cytotoxic, anti-inflammatory and anti-microbiological activities of two indigenous Venda medicinal plants
(BioMed Central, 2016 December 09) Sigidi, M. T.; Anokwuru, C. P.; Zininga, T.; Tshisikhawe, M. P.; Shonhai, A.; Ramaite, I. D. I.; Traore, A. N.; Potgieter, N.
Background: The Vhembe region of the Limpopo province has a rich tradition of medicinal plants use. Traditionally, boiled roots of Ziziphus mucronata are used in the treatment of boils, general swelling and other skin infections. A combination of leaf paste and root infusion treats measles, dysentery, chest complains, and gland swelling. Pterocarpus angolensis is famous for the treatment of menorrhagia, infertility in women, wounds and pain management. The purpose of the present study was to compare the cytotoxicity, anti-inflammatory potential and anti-microbial activities of Ziziphus mucronata and Pterocarpus angolensis from the Vhembe region. Method: U937, MeWo, Vero and RAW 264.7 cells were treated to various concentrations (50, 100, or 125 or 250 μg/ml depending on assays) of Ziziphus mucronata and Pterocarpus angolensis. Cytotoxicity assay was done using MTT; Antiinflammatory activity was assessed using NO production; Anti-bacterial activity was done using the Micro-Broth dilution method and Anti-mycobacteria activity was determined using the Alamar Blue Method while RT activity was measured by ELISA. Results: Cytotoxicity results showed that Pterocarpus was more toxic than Ziziphus as observed in the Vero and MeWo cells; however both displayed toxicity towards a Human cancer cell line. Both extracts did not inhibit nitrate production but induced significant increase in macrophage activation. The plant extracts have shown anti-tuberculosis activity at concentrations >500 μg/ml and there was moderation inhibition of HIV replication. Conclusions: The results obtained indicated that the extracts have pro-inflammatory properties, and the observed toxicity on malignant cell lines must be investigated further for promising anti-cancer drug therapy.
Open Access
Comparative population ecology of sclerocarya birrea (A. RICH.) HOCHST. Subspecies Caffra (SOND) in two rural villages of Limpopo Province, South Africa
(2018) Mocheki, Tebogo Alison; Ligavha-Mbelengwa, Maanda Hadzhi; Tshisikhawe, Milingoni Peter; Swelankomo, Nonkululeko; Tshivhandekano, Thivhilaeli Robert; Mokganya, Mokgaetji Georgina; Ramovha, Luvhimba Isaac; Masevhe, Ndivhaleni Anox
Sclerocarya birrea (A Rich.) Hochst. subspecies caffra (Sond) is a plant species belonging to the Anacardiaceae family. In South Africa, it is dominant in the Baphalaborwa area in the Limpopo Province. Throughout its distribution range, S. birrea is a keystone species that is highly utilized by herbivores and people. Understanding the utilization pattern assist in determing if the population is not negatively affected. The aim of this study was therefore to compare the distribution patterns and population status of S. birrea in Ga-Makhushane and Tshivhongweni villages in the Limpopo Province. The study will investigate the influence of culture in utilization of S. birrea resources since the study area are made up of communities of people from different cultures. Nearest-neighbour method of sampling individuals within a population of plants was used to collect data on S. birrea populations which was analyzed using Analysis of Variance. It was found that the populations were regularly distributed meaning there is an antagonistic relationship of the species with the users in both villages, and there was also a significant difference in distribution patterns between the two villages. It was concluded that although S. birrea is regularly distributed in both villages, there are differences in terms of interplant distances, heights, stem circumferences and canopy covers. It means that the two culturally different communities have different preferences when they harvest resources form S. birrea species
Embargo
Compatible components of the integrated pest management of Bathycoelia distincta (Hemiptera: Pentatomidae
(2024-09-06) Manzini, Shaun; Foord, S. H.; Joubert, E.
Two-spotted stink bug, Bathycoelia distincta Distant (Hemiptera: Pentatomidae), is a major pest of macadamia. It causes damage by directly feeding on macadamia kernel throughout the season and reducing nut quality by inducing nut abscission, premature nut abortion, necrotic lesions, deformed kernels, discoloration, or translucent blemishes on the kernel. Currently, growers rely on chemical insecticides to control stink bug populations. However, with overreliance and extensive use of chemical insecticides, the B. distincta has developed some resistance to certain active ingredients Furthermore, there is no doubt that agricultural intensification is the primary driver of the loss of biodiversity globally. Therefore, there is a need to develop Integrated Pest Management (IPM) strategies to effectively minimize the damage caused by B. distincta and the loss of biodiversity due to agricultural intensification. The goal of this study was to investigate the role of landscape context, elevation, flying vertebrates, and pesticide application in shaping arboreal arthropod assemblages and macadamia nut quality metrics and evaluate the efficacy of alternative pest control measures to control B. distincta, explicitly focusing on entomopathogenic fungi and egg parasitoids Trissolcus basalis (Wollaston, 1858) (Hymenoptera: Platygastridae). Landscape context and elevation were the principal factors that explained species richness and arthropod size. Species richness and insect size decreased with increasing pesticide application rate; however, it was not significant. Insect damage did not vary in response to pesticide application, but the proportion of sound kernels decreased significantly with increasing pesticide application. All entomopathogenic fungal treatments were effective against B. distincta, with chitinase enzyme leading to a 95% mortality rate. Under field conditions, EPFs and a chemical knock-down spray showed no significant difference between the treatments. All parasitoid treatments significantly affected B. distincta egg mortality, with two pairs reaching a 100% parasitism rate. The processes that increase sound kernel recovery seem to be related to an increase in invertebrate community diversity and arthropod size, and although the mechanisms related to this are not always clear, the results suggest that arthropod diversity could be a good proxy for these processes. On the other hand, the study results showed that EPFs and stink bug egg parasitoids, Trissolcus basalis, may be used as biological control agents against B. distincta. Overall, the thesis emphasizes the importance of reducing pesticide application and using biological control agents, promoting more sustainable agricultural practices, and supporting biodiversity to improve ecosystem service provided by pest natural enemies.
Open Access
The complete mitochondrial genome of Africa's largest freshwater copepod, Lovenula raynerae
(2018-11-18) Jooste, Candice M.; Emani-Khoyi, Arsalan; Gan, Hang Ming; Wasserman, Ryan J.; Dalu, Tatenda
Lovenula raynerae is the largest known African freshwater copepod. To date, it has only been sampled from ephemeral freshwater ecosystems. This paper reports the complete mitochondrial genome of L. raynerae, which was found to be 14,365 bp long. Base composition of 33.5% base A, 19.3% base G, 34.6% base T, and 12.5% base C was found, with 13 protein-coding genes, 22 tRNAs, and 2 rRNAs. This paper contributes to an improved understanding of phylogenetic relationships in an important crustacean group
Open Access
The complete mitogenome of a South African cryptic species of tadpole shrimp within the Triops granarius (Lucas, 1864) species group
(Taylor & Francis, 2018-11-02) Gan, Han Ming; Wasserman, Ryan John; Dalu, Tatenda; Rogers, D, Christopher
The complete mitochondrial genome of a cryptic species of tadpole shrimp from South Africa (Accession Number: MG770893) was recovered by low coverage shotgun sequencing. The mitogenome consists of 15,216 bp with a GC content of 30.95%. COX1 sequence alignment indicates that this specimen is the most closely related to Triops granarius with a pairwise nucleotide identity of less than 90% (86.6%). Phylogenetic analysis using whole mitogenome dataset supports its affiliation to the genus Triops with moderate support for its relatively basal position within the clade.
Open Access
Conservation Strategies of the Red Listed Brackenridgea zanguebarica Oliv. in Vhembe District Municipality, Limpopo Province, South Africa
(2019-09-20) Tiawoun, Makuete Andre; Tshisikhawe, M. P.; Gwata, E. T.
Brackenridgea zanguebarica Oliv. (Ochnaceae) commonly known as “Yellow Peeling Plane”, is an important medicinal plant species, and one of the most threatened tree species that is endemic to Thengwe village in Vhembe District, South Africa. It is widely harvested for traditional purposes and difficult to propagate sexually and asexually. Nowadays, it has become threatened and this unique plant population is believed to be declining in the Brackenridgea Nature Reserve (BNR). According to the Red List of South African plants, B. zanguebarica is considered a critically endangered medicinal plant. All these facts combined with a lack of knowledge on the conservation of this species prompted this study on its conservation. To ascertain the effective conservation and proper management of this multipurpose tree, this study was conducted with the aim to improve its conservation strategy by investigating current threats to the existence of B. zangueberica, the chemical constituents from the different plant parts, the propagation methods of the species, and the factors delaying the germination of its seeds. In this study, an assessment of the current population threats was important as a first step in conservation; this would update the status of the species in its natural habitat. The current status of Brackenridgea zanguebarica was conducted through an extensive field survey in the Brackenridgea Nature Reserve (BNR), where a belt transect method was deployed to record quantitative information, while the harvesting damage was estimated using a sliding scale from 0 to 5. The structure of the populations in terms of the stem diameter size classes showed a bell shape vi pattern. About 60% of individuals showed some signs of plant parts extraction as the stem bark was reported to be the main plant part harvested. The population structure, however, was dominated by juvenile plants due to the selective harvesting of mature individuals; this hinders fruit production leading to poor or slow seed production. The present study aimed to compare the chemical constituents and the antimicrobial activities of some parts of this plant species. The extracts were screened for phytochemicals using standard methods. Thin-layer chromatography (TLC) was carried out to compare the chemical constituents using various solvent systems of varying polarity. Agar well diffusion and broth microdilution methods were used to evaluate the antimicrobial activity and the minimum inhibitory concentrations (MIC) of plant extracts respectively, against three bacteria and four fungi. The phytochemical analysis revealed a close similarity of various phytoconstituents of the three plant parts (stem bark, twigs and leaves). TLC analysis showed a slight difference in the acetone extract of different plant parts with more bands on the leaves than the stem bark and twigs. Acetone extracts of the three plant parts exhibited varying degrees of antimicrobial activity against Staphylococcus aureus and Candida glabrata, while none of the extracts showed any activity against Escherichia coli, Klebsiella pneumonia, Candida albicans, C. krusei, and C. parapsilosis. However, analysis of the antibacterial activity of various extracts revealed that the best inhibitory activity was produced by the stem bark extract compared to the leaf and twig extract. vii The sustainable way to meet the growing demand of Brackenridgea zanguebarica is to increase its availability through propagation practices. Unfortunately, the conservation of B. zanguebarica is hampered by lack of information on how it can be propagated. Sexual and asexual propagations were conducted to determine an efficient method to increase the number of individuals of this plant species. Seed propagation was carried out to study the effect of various pre-treatments on germination, in order to understand the germination requirements; vegetative propagation was conducted to assess if B. zanguebarica could be successfully propagated via stem cuttings if the appropriate growth hormones and growing media were applied. Brackenridgea zanguebarica seed did not germinate at all under any of the conditions tested. However, the results, showed the potential of propagating this species from stem cutting despite the poor results obtained. Thus B. zanguebarica was found to be difficult to propagate sexually and asexually. Seeds serve as a means of reproduction and a vital element to ensure the survival of plant species. Seed germination is controlled by a number of factors. The propagation of B. zanguebarica via seed is very difficult and research has not been undertaken to understand possible factors that may delay its germination. This study was aimed to investigate and describe both the morphological and anatomical features of B. zanguebarica seed, in order to identify structural features implicated in its poor germination. To achieve this goal, a morphological and anatomical study was conducted based on the observation of seeds under a scanning electron microscope (SEM) and light microscopy (LM). Water uptake potential was assessed by the increase in seed mass. The morpho-anatomical analysis indicated that some structures of the seed, such as seed coat, and the presence of endosperm viii surrounding the embryo that consisted of two prominent cotyledons, seem to greatly hinder the germination of this species. The research findings provided information regarding the seed structure which is one important step in identifying useful techniques to improve seed germination for conservation purposes.
Open Access
Detecting threats to Encephalartos transvenosus (Limpopo cycad0 in Limpopo province, South Africa through indigenous knowledge
(2016-08-09) Bamigboye, Samuel O.; Tshisikhawe, Peter M.; Taylor, Peter J.
Indigenous knowledge contains valuable information which is often essential to biodiversity and species conservation. The traditional knowledge of people in local communities can enhance conservation policies and planning and also reveal local perspectives in relation to endangered species. Cycads as a vascular plant group contain the highest percentage of threatened plant species, at global, regional, national and community levels. In this study we focused on Encephalartos transvenosus Stapf & Burtt Davy, a cycad species endemic to Limpopo province in South Africa. Despite every effort to conserve this highly endangered species the threats keep increasing and the population keep decreasing. Through indigenous knowledge, we discovered a location of this species not yet conserved within Vhembe district on the Soutpansberg mountain range in Limpopo province, South Africa. Practices such as bark harvesting, and uprooting of young seedlings were discovered at this population. All these practices noticed at this location are detrimental to in situ conservation of the cycads. This study hereby revealed that indigenous knowledge has a great role in cycads’ conservation. Through the local communities, factors that are threatening cycads existence can be determined and the local community can also be integrated in effective conservation plan that discourage illegal harvesting of cycads.
Open Access
The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens, 1868), in Lake Kariba, inferred using stomach content and stable isotope analyses
(Invasivenet, 2018-01-27) Marufu, Lighthouse T.; Dalu, Tatenda; Phiri, Crispen; Barson, Maxwell; Simango, Rutendo; Utete, Beaven; Nhiwatiwa, Tamuka
The diet of an invasive crayfish, Cherax quadricarinatus (Von Martens 1868), in Lake Kariba, was investigated using stomach content analysis (SCA) and stable isotope analysis (SIA). The frequency of occurrence of macrophytes and detritus ranged between 63.6–97.1% and 20–45.5%, respectively, and the index of relative importance ranked these as the two most important food items across all size classes. Significant differences in the ranking of fish, macroinvertebrates and crayfish were found between size classes 29–37.9, 38–46.9 and 47–55.9 mm. Stomach content analysis showed 16% of crayfish stomachs were empty. Feeding intensity differed significantly between size classes and ranged from 3.46 to 5.21. Stable isotope analysis was done by comparing δ13C, δ15N and C/N ratios in crayfish muscle and potential dietary items in the lake. Macrophytes were the most dominant food item (57%), followed by macroinvertebrates (20%), then detritus, and finally fish and crayfish. Stable isotope analysis revealed that all crayfish size classes analysed were in the same trophic level. Nevertheless, while SCA showed high dietary overlap among all crayfish size classes (>65%), SIA showed that small crayfish (< 28.9mm) had limited overlap with large crayfish (> 56mm), with the former showing a higher proportion of macroinvertebrates in their diet. In Lake Kariba, C. quadricarinatus predominantly feeds on macrophytes, macroinvertebrates and detritus, which may bring about nutrient cycle alterations in the lake. Littoral habitat changes caused by the feeding characteristics of C. quadricarinatus might also lead to competition with, and eventual displacement of, some native littoral fishes in this lake
Open Access
The distribution patterns, utilisation and conservation of Sclerocarya birrea (A. RICH.) HOCHST, SUBSP. CAFFRA in two villages of the Limpopo Province, South Africa
(2016-05) Mocheki, Tebogo Allison; Ligavha- Mbelengwa, M. H.; Tshisikhawe, M. P.
See the attached abstract below
Open Access
Distribution, population status and conservation of the samango monkey (Cercopithecus albogularis schwarzi) in the Limpopo Province, South Africa
(2020-02) Linden, Birthe; Taylor, Peter J.; Dalton, Desire L.
A general introduction about the need for studying forest dwelling primate populations in fragmented landscapes and more specifically in the Soutpansberg is given in Chapter 1. Forests affected by fragmentation are at risk of losing primate populations over the long term. In addition, although the impact of fragmentation on primate populations has been studied in many places in Africa, Asia and South America there is no consensus of how the different primate species react to forest disturbance and fragmentation. This study aims to investigate the impacts of natural and anthropogenic forest fragmentation on the Soutpansberg samango monkey population including their distribution, genetics, and phylogeography, identifying threats and mitigation measures. To date, no detailed population level research has been undertaken on samango monkey populations in the far north of their South African distribution. By collecting a diverse data set, in addition to existing ecological data, this study generates conservation and management recommendations suited specifically to the study area and the study species and provides baseline data for future monitoring. Chapter 2 details how through creating an accurate forest distribution map and collecting samango monkey distribution records through surveys we were able to investigate how both natural and anthropogenic forest fragmentation influences the distribution of samango monkeys in the Soutpansberg. We explored forest patch occupancy and connectivity, determined the degree and nature of matrix utilisation and identified possible threats to forests and samango monkeys between the contrasting landscapes of the eastern and western Soutpansberg. Here we found that samango monkeys largely occupied forest patches <100 ha in size and that the Soutpansberg has very few forest patches > 100 ha available. We showed that samango monkeys used all components of the surrounding matrix and that lone or bachelor group males used the matrix more extensively than groups. We found that paved roads pose a major threat, however not a barrier, to samango monkey populations when navigating the matrix. Forest connectivity was found to be influenced by the distance between patches and possible corridors or stepping stones of isolated forest patches connecting them. Patterns found in this chapter contrasted between the eastern and western landscapes requiring different adaptive strategies from the samango monkeys and different conservation approaches from practitioners. In this chapter we conclude that samango monkeys, having evolved in fragmented landscapes, are comparatively tolerant and adaptable to a human- transformed matrix. In Chapter 3 we focused on the effects that natural and anthropogenic habitat fragmentation in the Soutpansberg has on the genetic diversity and structure of the samango monkey population in the mountain range. Here we used microsatellite and mitochondrial DNA data from faecal and tissue samples collected from four local samango monkey populations across the Soutpansberg. We also included samples from an outlying population on the escarpment south of the mountain, the most likely historical migration route into the Soutpansberg. Our analyses showed that the Soutpansberg population is divided across the mountain and that genetic diversity within the Soutpansberg decreases with increasing distance to the escarpment population and from east to west. We found a lack of contemporary gene flow suggesting that the Soutpansberg population is completely isolated from the closest source population in the escarpment and that populations within the mountain range are isolated from each other. Based on our results we suggest that extensive anthropogenic changes to the landscape in the eastern Soutpansberg and distance between high canopy forest patches in the western Soutpansberg appear to have reduced the ability of samango monkeys to disperse between sampling areas. Overall, we found that natural and anthropogenic fragmentation and geographical distance are potential drivers for the observed population genetic differentiation and that the matrix surrounding forests and its suitability for samango utilisation plays a role at the local scale. In this chapter we conclude that the degree of samango monkey population subdivision and the apparent lack of contemporary migration between populations raises concerns about the long-term viability of populations across the mountain range. Having identified road fatalities as the main direct anthropogenic threat samango monkeys are exposed to when utilizing the matrix, we further investigated this issue in more detail in Chapter 4. Here we aimed to get a better understanding of where roadkills most likely occur and how to mitigate these through using suitable canopy overpasses. As road fatalities threaten primate populations globally, we used the samango monkey (Cercopithecus albogularis) as a model species to test the suitability of two different canopy bridge designs through field experimentation and behavioural data collection for arboreal guenon roadkill mitigation. Analysis of actual roadkill data collected in the study area provided insights into the nature of high-risk localities. We showed that canopy overpasses are a viable intervention for mitigating arboreal guenon road fatalities, reducing the probability that monkeys will cross a road on the ground. Samango monkeys clearly preferred a pole bridge over a rope ladder design and canopy bridges were preferred to trees and the ground when the tree canopy was open. Pole bridges were also used by other non-guenon primates and non-primate species. We showed that although samango road kills were not predictable in time (no seasonality), adult female and immature fatalities were predictable in space, restricted to bisected riparian zones and roads close to intact forests. We further found that adult male road fatalities can be expected in seemingly unsuitable habitat areas. This chapter highlights the importance of the correct interpretation of spatial, temporal and demographic data on road fatalities and how experimental research prior to installing crossing structures could increase mitigation impact. In Chapter 5 we investigate the regional phylogeography of samango monkeys, providing a deeper understanding into their evolutionary history in repeatedly fragmented forest habitat due to paleoclimatic fluctuations. Here we used mtDNA and microsatellite data obtained from tissue samples from a coastal population (Vamizi Island) in Mozambique and compared this to existing data from South Africa. The additional analysis of Mozambique animals allowed us to further test the number and timing of radiation events of Cercopithecus monkeys in southern Africa. In this chapter we propose the occurrence of a single, north-south radiation event during the midPleistocene along the Afromontane forest belt and that after the Last Glacial Maximum, samango populations re-radiated into (re)established coastal forests on a more local scale. Taking the findings from all chapters together we provide overall conclusions and conservation and management recommendations in Chapter 6. Here we also include interview data to give insights into public perceptions of samango monkeys and possible human-primate conflicts as we consider this an important aspect of conservation planning. In this final chapter we conclude that although samango monkeys appear comparatively adaptable to changes in the matrix surrounding their forest habitat, direct threats and forest patch isolation by distance may pose risks to populations in future. We advocate that conservation and management strategies aimed at the longterm persistence of the samango monkey populations and their forest habitat across the Soutpansberg should be formulated separately for the eastern and western parts of the mountain range as differing landscape variables pose different threats to forest and samango monkeys, thus requiring separate conservation and management approaches. We further recommend explicit mention of distinct management requirements for maternal groups and lone or bachelor group males to achieve a holistic conservation approach for samango monkey populations on the landscape scale. Findings of our study are not only relevant for samango monkey populations in the Soutpansberg but also for populations elsewhere in South Africa and southern Africa generally where forests and samango monkeys share the same paleohistory and current anthropogenic threats.
Open Access
Documentation and nutritional evaluation of some wild edible fruit plants and traditional vegetable of the Vhembe District Municipality, Limpopo Province, South Africa
(2019) Mokganya, Mokgaetji Georginah; Tshisikhawe, Milingoni Peter; Mushaphi, Lindelani Fhumudzani
Wild plants have been used since time immemorial by native people all over the world. In many sections of the rural areas, people traditionally harvest wide range of leafy vegetables, roots tubers and fruits from the wild because of their taste, cultural practices, as food supplements or to tide over food shortage. It has been reported that wild plants have been recognized to have potential that satisfies the needs on household food and income security. Millions of people in many developing countries do not have adequate sources of food to meet their daily nutritional requirements and furthermore, many people are suffering from malnutrition due to lack of one or more micronutrients. Thus, in most situations, rural communities rely on wild resources including edible vegetables and fruits to meet their daily food requirements. Relatively little research projects conducted in the Vhembe District paid attention on wild edible plants and their nutrients. Therefore, the aim of this study was to further document wild edible plants and to evaluate nutritional status of some of these plants. To achieve this, an investigation was conducted in the four local municipalities of the Vhembe District municipality. Ten homesteads from four villages of each of the four local municipalities were randomly sampled to select respondents of this project. A total of 160 informants were interviewed through semi-structured questionnaires to firstly check the knowledge transfer from elderly members to youth members of Vhembe communities. This study demonstrated the major indigenous debility among the youth members who live in urban villages. Secondly, information concerning other different use categories was gathered through interviews with the 160 informants. Documented use categories mentioned during the interviews include food, medicine, beverages, construction, firewood, cosmetic, dye and artifacts. Sclerocayra birrea had eight use categories as compared to other edible fruit plant species. The list of documented wild edible plants includes trees, herbs, creepers, climbers and shrubs. Leaves of the mentioned growth forms were mostly used as compared to plants parts such as fruits, rhizomes, tubers, seeds and flowers. Some of the plants were mentioned to be available during certain seasons, therefore they were preserved using the sun drying method. Some edible parts can either be collected and sun dried or collected, cooked and then sun dried. Micronutrients are essential for the normal growth of children; however, there is disturbing reports of low intake of micronutrients rich foods eaten by children residing in poor rural areas. Some reports showed the low intake of Vitamin A in black children younger than 10 years of ages. Vitamin A deficiency continues to be a major public health problem in South Africa; therefore, this study also evaluated Vitamin A and C statuses from selected vegetables. Plants that received attentioned were selected based on their frequency of use and availability. Leaves of Amaranthus thunbergii and Amaranthus hybridus had outstanding Vitamin C concentration of 69.106 mg/100g and 43.299 mg/100g respectively. Majority of the wild edible vegetables (i.e. six out of eight) evaluated contain substantial quantities of β-carotene. Exceptionally, leaves of Solanum retroflexum contained high level of 10.905 β-carotene. The study therefore recommends an urgent need for the documentation and promotions or awareness campaigns as a way of dealing with the loss of indigenous knowledge. Moreover, researches related to cultivation of wild edible plants must be considered. Nevertheless, despite the rich indigenous knowledge on the medicinal use of the wild plants which is well documented; more research particularly to serve the concern on socio-economic, pharmacological and nutritional aspects still require satisfactory attention.