Research Articles (Plant Production and Soil Science)
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Item DNA barcoding and anti-tyrosinase activities of three species-representative populations of the genus Greyia Hook & HarvBotha, Ine; De Canha, Marco Nuno; Oberlander, Kenneth Carl; Botes, Jana; Lall, Namrita; Berger, David Kenneth (Elsevier, 2026-02)The tree genus Greyia is endemic to South Africa and Eswatini. The Eastern Cape species Greyia flanaganii Bolus is confined to a limited range west of the Kei River. Greyia radlkoferi Szyszyl. occurs in Limpopo Province, whereas Greyia sutherlandii Hook. & Harv. is associated with KwaZulu-Natal Province, but the ranges of these two species overlap in Mpumalanga Province. Greyia trees are of value to the bioeconomy as leaf extracts from G. flanaganii and G. radlkoferi possess anti-tyrosinase activity and low toxicity and are being developed in herbal formulations for the treatment of skin hyper-pigmentation. The main active compound is 2’,4’,6’ trihydroxydihydrochalcone. However, there are no reports of medicinal assays from Greyia trees growing in their natural habitat, it is not known whether the third species - G. sutherlandii - has activity, and DNA barcode data is limited. To address these knowledge gaps, we sampled five trees per Greyia species that matched morphological descriptions and were from sites close to type specimen collection records. Leaf ethanolic extracts from G. sutherlandii had similar average anti-tyrosinase activity (IC50 = 84 µg/mL ± 18 [SD]) when compared to G. radlkoferi (58 µg/mL ± 21) and G. flanaganii (72 µg/mL ± 11). High Performance Thin Layer Chromatography showed the presence of the active compound in all three species, although it was below the detection limit of 4.4 µg/10 mg extract in two of the G. flanaganii samples. Considering the difficulty in differentiating G. sutherlandii from G. radlkoferi morphologically in the field and production orchards, we investigated DNA barcoding as a method of species-specific authentication. Phylogenetic analysis using Bayesian Inference from combined ITS, trnL-F, matK and psbA-trnH barcodes from the 15 Greyia trees plus Genbank sequences indicated (i) clear differentiation from other lineages in the order Geraniales, but (ii) extremely short internal branches within Greyia and poor discrimination between Greyia species and individuals. Our study has shown that natural populations of all three species sampled in late summer exhibit consistent leaf anti-tyrosinase activity between biological replicate trees. We have demonstrated activity from G. sutherlandii for the first time, indicating that this species can also be deployed in production orchards. However, alternative phylogenetically informative SNP markers need to be developed to provide species-specific authentication of Greyia extracts in herbal products. HIGHLIGHTS • First report of anti-tyrosinase activity of leaf extracts from wild-growing Greyia spp. • Greyia sutherlandii leaf extracts shown to have anti-tyrosinase activity for the first time. • HPTLC method developed to quantify the active compound 2′,4′,6′-trihydroxydihydrochalcone. • DNA barcoding (ITS, matK, trnL-F, psbA-trnH) conducted on core populations of three Greyia spp. • DNA barcode phyogeny discriminates Greyia spp. from other Geraniales genera. • G.sutherlandii and G.radlkoferi not resolved phylogenetically with DNA barcodes. • G. sutherlandii and G. radlkoferi hard to differentiate in the field morphologically.Item Eczema : etiology, subtypes, therapeutic approaches and socioeconomic impactCuyler, Marize; Twilley, Danielle; Lall, Namrita (Frontiers Media, 2026-01)Eczema is an inflammatory skin condition that affects individuals of all ages worldwide. Patients may develop various forms of eczema, including atopic dermatitis, contact dermatitis, which is often associated with an allergic response to various stimuli, dyshidrotic eczema which develops on the palms and soles, asteatotic dermatitis that predominantly occurs in elderly patients, nummular eczema characterized by its cylindrical shape lesions and seborrheic dermatitis often located on patient's scalps, back, face and chest. Extensive studies have been conducted on atopic dermatitis, however, limited information such as their etiology, effect on the immune system and potential treatments are available on the other types of eczema. The socioeconomic impacts of eczema include the cost of conventional treatments such as corticosteroids, immunosuppressive agents and phototherapy, expenses related to specialists’ consultation and the effect on work and school productivity. The impact of atopic dermatitis on patients’ quality of life, social functioning and individual healthcare expenses has been extensively studied in other countries but remains underreported in South Africa. Reports have estimated the annual direct and indirect costs in Australia, the United Kingdom and the United States, however reports are limited for South Africa. This study aimed to provide information on the different types of eczema's etiology, their respective socioeconomic impact in South Africa in correlation to the above mentioned inflated yearly cost, and conventional, targeted and alternative treatments commercially available. Several knowledge gaps were identified in this study, including the limited availability of information on asteatotic dermatitis, dyshidrotic dermatitis and nummular eczema, the effect most commercially available treatments have on other eczema subtypes and an in-depth review of the socioeconomic impact of eczema within the African continent.Item Perception of ecosystem services use across vegetation types and land use zones in Vhembe Biosphere Reserve, South AfricaChirwa, Paxie W.; Tshidzumba, Ratsodo Phillip; Makhubele, Lucky; Araia, Mulugheta Ghebreslassie; Honold, Martin A.; Hilmers, Torben; Pretzsch, Hans (MDPI, 2026-01)Sustainable management of ecosystem services (ESs) is critical for balancing human well-being with conservation goals in biosphere reserves. This study examined the spatial and socio-demographic variation in the use and perceived importance of provisioning, regulating, supporting, and cultural ESs across different vegetation types and land use zones in the Vhembe Biosphere Reserve (VBR), South Africa. Household surveys were administered to 447 randomly selected households in six rural communities. Descriptive statistics, Chi-square tests, Kruskal–Wallis tests, and Friedman mean ranking analysis were employed. Results revealed significant differences (p < 0.05) in ES distribution and value across vegetation types, land use categories, and household characteristics, including income, education, age, and gender. Provisioning services, particularly fuelwood, wild fruits, and wild vegetables, were most intensively utilized in Mountain Woodland Moist and Ironwood Forest areas due to accessibility and limited livelihood alternatives. Regulating and supporting services, including water purification, erosion control, and habitat provision, were associated with forested and traditionally protected areas. Cultural services reflected strong socio-cultural ties, especially in sacred and tourism-associated landscapes. Overall, the study highlights the multifunctional importance of forested and agroforestry systems in rural livelihoods, emphasizing the need for integrated, culturally informed, and ecologically sound land use planning to support sustainable development in the VBR.Item Perceived abundance and cultural-economic use-value of tree species in the Mopane Woodlands, Mopani District, South AfricaMakhubele, Lucky; Dunbar, Audrill; Chirwa, Paxie W. (MDPI, 2026-01)Identifying the key products of mopane woodlands, the perceived abundance of species, and the associated use values have important implications for rural communities and the sustainable use of mopane woodlands. This study examined local perceptions of tree species abundance and their associated use-values across four communities in the Mopani District, South Africa. The semi-structured questionnaire and key informant interviews were used to collect the data. The data were analyzed using descriptive statistics, the Friedman test, the Smith Salience Index, Kendall’s W, Pearson correlation, and the Fidelity test. There was a very strong level of agreement (W = 0.83) among the communities regarding the perceived abundance of tree species, and this agreement was statistically significant (χ2 = 19.85, p < 0.05). The Colophospermum mopane, Sclerocarya birrea, and Combretum imberbe are the most perceived abundant species in the study areas and have high value. The tree species with high use-value showed a positive correlation with the perceived abundance of tree species, conforming to the study’s ecological apparency hypothesis. The more apparent species had more use value and perceived abundance.Item Growth and physiological responses of two sugarcane cultivars exposed to elevated surface ozoneLaban, Tracey L.; Van Zyl, Pieter G.; Liebenberg, Shawn C.; Beukes, Johan P.; Berner, Jacques M.; Van Heerden, Philippus Daniel Riekert; Wright, Caradee Yael (Academy of Science of South Africa, 2026-01)Surface ozone (O3) pollution is known to have a detrimental effect on agriculture whilst rising carbon dioxide (CO2) concentrations are sometimes found to offer plants protection against O3 effects. Considering the important role of sugarcane (Saccharum spp. hybrids) as a major food crop in South Africa and its contribution to the national economy, the tolerance of this crop to O3 damage must be established. A pilot study using open-top chambers was conducted whereby two local commercial sugarcane cultivars (NCo376 and N31) were fumigated during the summer growth season to explore the effects of elevated O3 as well as the interacting effects of O3 and CO2 on various stress and crop quality indicators. Statistical significance of differences in treatment means was analysed by hierarchical linear modelling to account for variability between chamber and pots in explaining changes across individual plants. The results revealed a significant reduction in the number of dead leaves (senescing) for the N31 cultivar exposed to elevated O3 compared with the other treatments. There was also a statistically significant decrease in chlorophyll fluorescence (used to assess photosynthetic performance) in the O3-treated NCo376 plants. This pilot study shows limited effects of O3 fumigation on growth and physiology, with preliminary indications that sugarcane is less sensitive to O3 than other crops. An increase in O3 concentrations associated with future climate change is expected, which will have implications for cultivar selection as a possible adaptation strategy to reduce susceptibility of this crop to O3. SIGNIFICANCE : • This article adds to the existing literature on sugarcane and ozone (O3). We present a pilot study for two cultivars of sugarcane and explore interacting effects of O3 and carbon dioxide (CO2) on various stress and crop quality indicators. • We employed a mixed effects model to account for variability between chamber and pots, a challenge when working with plants. • This is the first time African sugarcane has been investigated and, although the findings show limited statistical effect of O3 and CO2, future studies can vary the conditions of this experiment to produce more data points for a dose-response function.Item Nuclear phylogenomics reveals strong geographic patterns in the evolutionary history of aloe and related genera (alooids)Woudstra, Yannick; Rees, Paul; Rakotoarisoa, Solofo E.; Klopper, Ronell Renett; Smith, Gideon F.; Rønsted, Nina; Grace, Olwen M. (Oxford University Press, 2025)BACKGROUND AND AIMS : With >700 species, Aloe and its generic kin (alooids) are a morphologically diverse group of succulent plants with a wide range across Africa, Madagascar and the Arabian Peninsula. Species such as Aloe vera and A. ferox are cultivated at scale for natural products, whole foods, and cosmetics. Despite substantial α-taxonomy contributions, infrageneric classification of Aloe has remained unresolved. Molecular systematics has been compromised by the lack of informative characters in standard markers and high costs of obtaining informative nuclear loci from large genomes (e.g. >15 Gbp), and the difficulty of obtaining quality DNA extractions from material of known provenance. Here these constraints are overcome with target capture sequencing, which allows cost-effective sequencing of informative low-copy nuclear loci and unlocks genetic resources from preserved specimens in herbaria as well as silica-dried tissues. METHODS : Using a custom kit for alooids, 189 nuclear loci were sequenced in 294 species, including 50 herbarium specimens, to build a new phylogenomic framework for the big genus Aloe and 11 closely related alooid genera. Genus-level representations of non-alooid members of Asphodelaceae were sequenced with the same tool. The monophyly of Asphodelaceae subfamilies, alooid genera and infrageneric taxonomic groups of Aloe sensu stricto was tested with the obtained topologies. KEY RESULTS : The new phylogenomic framework demonstrates the monophyly of the alooids and confirms recent classifications in which smaller genera (Aloidendron, Aloiampelos, Aristaloe, Gonialoe, Kumara) are separated. Strong geographic patterns in the Aloe phylogeny are contrasted by less obvious phylogenomic structure in habit (growth form), and vegetative or reproductive morphology, which are mainstays of α-taxonomy. CONCLUSIONS : Repeated incidents of adaptive radiation and niche specialization appear to underlie species diversity in Aloe. This study illustrates the power of combined (nuclear) phylogenomic and α-taxonomic inference, including the utility of herbarium genomics, in resolving the systematics of big genera.Item Pastures established on rehabilitated surface coal mined land : an assessment of forage production and implications for livestock grazingCele, Emmanuel Nkosinathi; Rapiya, Monde; Sanders, Wayne; Truter, Wayne Frederick (Taylor and Francis, 2025-10-26)Currently, land rehabilitation best practice in South Africa is to revegetate ameliorated soil with grass mixtures. These grasses have valuable grazing potential that can deliver great benefits to livestock farmers. However, due to paucity of research and published findings, the viability of such post-mining land use in South Africa remains unclear. To evaluate the grazing potential of rehabilitated mine lands, this study examined soil properties, biomass, and veld condition across a 4–30-year chronosequence. Despite suboptimal pH in the majority of sites, there were satisfactory levels of Na, K, Ca and Mg. There was biomass production in all sites with high levels of basal cover (36–91%). Percentage veld condition scores were moderate (40–60%) to excellent (60–100%) in all sites. Decreaser species were the most abundant and the grazing capacity in all sites was 2.7–3.6 ha LSU−1. These results were indicative of the ability of rehabilitated sites to withstand the impacts of soil erosion, with high potential to meet forage requirements of animals in terms of quantity. Based on these results, the implementation of controlled cattle grazing on rehabilitated mine lands in Mpumalanga, South Africa, appears to be a practicable post-mining land use option.Item Antibacterial and antibiofilm activity of 8-Hydroxyquinoline derivatives against Mycobacterium and Staphylococcus speciesLall, Namrita; Kok, Anna-Mari; Oosthuizen, Carel Basson; Verma, Surjeet; Chassagne, Francois; Vo, Phuc H.; Ho, Khanh-Van; Lin, Chung-Ho; Quave, Cassandra L.; Twilley, Danielle (Wiley, 2025-12)A series of 8-alkoxyquinoline derivatives (QD-1-12) were designed and synthesized on the basis of analogues of 8-hydroxyquinoline (8-HQ) (HQ 1-4). The compounds were evaluated for biofilm inhibition against Mycobacterium smegmatis and Staphylococcus aureus, including antibacterial activity against Mycobacterium tuberculosis, M. smegmatis and S. aureus. Cytotoxicity was evaluated against human monocyte (U937) and African green monkey kidney (Vero) cell lines. The 8-O-prenyl derivative (QD-12) showed a minimum inhibitory concentration (MIC) of 12.5 µM, indicating an approximate 8-fold increased selectivity for the biofilm phenotype and an increased inhibitory activity against methicillin-resistant S. aureus (MRSA) by up to 2-fold. 5,7-Dichloro-8-hydroxy-2-methylquinoline (HQ-2) showed the highest inhibitory potential with MIC values of 0.1, 1.56, 2.2 and 1.1 µM against M. tuberculosis, M. smegmatis, methicillin-sensitive S. aureus (MSSA) and MRSA, respectively. The results indicate the importance of the 8-OH group for antibacterial and antimycobacterial activity. Cytotoxicity revealed low-to-moderate toxicity of 8-HQ (HQ-1). All the compounds, except HQ-1, were tested for the first time for their growth and biofilm inhibitory activity against Mycobacterium spp. and S. aureus.Item Advancing entomopathogenic fungi for improved management of Phthorimaea (Tuta) absoluta (Lepidoptera: Gelechiidae)Kinyanjui, Grace; Mawcha, Kahsay Tadesse; Ndolo, Dennis (Oxford University Press, 2025-09)Phthorimaea (Tuta) absoluta (Meyrick), a destructive pest of tomato, is currently mainly controlled using chemical insecticides. However, overdependence on chemical control induces resistance among P. absoluta populations and negatively impacts human health and the environment. Therefore, there is a need to adopt complementary pest control methods. Biological control of P. absoluta using integrated pest management (IPM) strategies incorporating entomopathogenic fungi (EPFs) holds great promise for suppressing pest populations and reducing insecticide applications. In this review, we discuss the relevance of EPFs in controlling P. absoluta and highlight their value as an integral component of IPM programs. The review provides an overview of strategies to address the challenges that limit research, development, wide-scale commercialization, and adoption of EPFs, particularly in sub-Saharan Africa. It also highlights technological advances that could improve the insecticidal activity of EPFs to harness their biocontrol potential fully. Further, the review recommends actionable measures for the broad and sustained application of EPFs as components of IPM programs for the control of P. absoluta.Item Optimized molecular detection of Cryptosporidium within the water-soil-plant-food nexus : advancing surveillance in agricultural systemsSchipper, Robyn Marijn; Richter-Mouton, Loandi; Korsten, Lise (Elsevier, 2025-08)Cryptosporidium, a protozoan parasite causing severe diarrheal illness in humans and animals, poses detection challenges due to low parasite concentrations, inhibitors, and inefficient DNA extraction. This study optimized DNA extraction and detection of Cryptosporidium in environmental samples and evaluated their practical use in agriculture. After evaluating 11 DNA extraction methods from spiked phosphate-buffered saline (PBS) sam-ples, three methods for molecular detection of Cryptosporidium in water, soil, and fresh produce were selected and further tested using real-time PCR. A total of 188 artificially contaminated samples were prepared, consist-ing of distilled water (n = 36), environmental water (n = 44), soil (n = 36), and fresh produce (lettuce and spinach; n = 72). Each sample was inoculated with serial dilutions of 12,500 to 5 Cryptosporidium oocysts and tested using real-time PCR and droplet digital PCR (ddPCR) to evaluate detection sensitivity. Results demon-strated that extraction performance varied by matrix, with two spin-column kits excelling for water and another for soil and produce. DNA from as few as five oocysts was occasionally detectable, with ddPCR being less prone to be affected by PCR inhibitors than real-time PCR. These methods were then applied to detect Cryptosporidium in 210 environmental samples (water, soil, produce) from South African small-scale farms. None of the samples tested positive with real-time PCR, while ddPCR detected Cryptosporidium in 13.6% of water, 23.3% of soil, and 34.7% of fresh produce samples. Surface water showed the highest contamination at 28.6%. Soil amended with both fertilizer and manure had a 45% contamination rate. Among vegetables, roots were most affected (46.7%), followed by fruiting (40%) and leafy greens (30.15%). These findings high-light the health risks of Cryptosporidium in food systems and the need for improved detection methods to enhance surveillance and inform future outbreak prevention strategies.Item Evaluation of multimodel averaging approaches for ensembling evapotranspiration and yield simulations from maize modelsNand, Viveka; Qi , Zhiming; Ma, Liwang; Helmers, Matthew J.; Madramootoo, Chandra A.; Smith, Ward N.; Zhang, Tiequan; Weber, Tobias K.D.; Pattey, Elizabeth; Li , Ziwei; Wang, Jiaxin; Jin, Virginia L.; Jiang, Qianjing; Tenuta, Mario; Trout, Thomas J.; Cheng, Haomiao; Harmel, R. Daren; Kimball, Bruce A.; Thorp, Kelly R.; Boote, Kenneth J.; Stockle, Claudio; Suyker, Andrew E.; Evett, Steven R.; Brauer, David K.; Coyle, Gwen G.; Copeland, Karen S.; Marek, Gary W.; Colaizzi, Paul D.; Acutis, Marco; Alimagham, Seyyed Majid; Babacar, Faye; Barcza, Zoltan; Basso, Bruno; Bertuzzi , Patrick; Constantin, Julie; De Antoni Migliorati, Massimiliano; Dumont, Benjamin; Durand, Jean-Louis; Fodor, Nandor; Gaiser, Thomas; Garofalo, Pasquale; Gayler, Sebastian; Giglio, Luisa; Grant, Robert; Guan, Kaiyu; Hoogenboom, Gerrit; Kim, Soo-Hyung; Kisekka, Isaya; Lizaso, Jon; Masia, Sara; Meng , Huimin; Mereu, Valentina; Mukhtar, Ahmed; Perego, Alessia; Peng, Bin; Priesack, Eckart; Shelia, Vakhtang; Snyder, Richard; Soltani , Afshin; Spano, Donatella; Srivastava , Amit; Thomson, Aimee; Timlin, Dennis; Trabucco, Antonio; Webber, Heidi; Willaume, Magali; Williams, Karina; Van der Laan, Michael; Ventrella , Domenico; Viswanathan, Michelle; Xu, Xu; Zhou, Wang (Elsevier, 2025-11)Combining multi-model simulations can reduce the uncertainty in model structure and increase the accuracy of agricultural systems modeling results. This improvement is essential for supporting better decision making in irrigation planning and climate change adaptation strategies. Besides the commonly used arithmetic mean and median, many multi-model averaging approaches (MAA), widely examined in groundwater and hydrological modeling, but these additional MAA have not been examined in agricultural system modeling to improve the simulation accuracy. Therefore, the objective of this study is to evaluate the performance of seven MAA: two equal weighted approaches (Simple Model Averaging (SMA) and Median) and five weighted approaches (Inverse Ranking (IR), Bates and Granger Averaging (BGA), and Granger Ramanathan A, B, and C (GRA, GRB, and GRC)) in combining results of multiple agricultural system models. The Granger Ramanathan methods differ in their constraints: GRA employs conventional least squares, GRB requires non-negative weights that total to one, and GRC reduces absolute errors for robustness against outliers. The evaluation was conducted using maize yield and daily ETa simulations for both blind (uncalibrated) and calibrated phases of data from two groups of maize sites (Group A and Group B) across North America. The modeling results from the blind and calibrated phases were combined for all maize models and group maize models. Overall, all MAA performed better than individual crop models for blind and calibration phases. Specifically, the GRB model averaging method provided the closest match to measured values for daily ETa, while GRA was the most accurate for maize yield in most cases across all sites and phases. GRB improved daily ETa estimation over the median by an average of 4 % and 8.5 % in terms of RRMSE, while GRA enhanced maize yield estimation over the median by 7.5 % and 10.9 % for Group A and Group B sites, respectively. Notably, the improvement was greater in the blind phase for both groups of maize sites. An ensemble of group maize models with varied structures performed nearly as well as an ensemble of all maize models in simulating daily ETa and yield for Group A and Group B sites. Based on the results, we recommend GRA for crop yield and GRB for ETa simulations for maize, but both methods require observed yield and ETa data for their application; however, in the absence of observed data, we recommend the SMA method as it performs better than the median. However, the performance of these MAA methods may differ for other crops (e.g., soybean, wheat, canola, potato, alfalfa) or regions, and it should be evaluated in future studies.Item South African soil, land cover and weather generator file databases for SWAT applicationsLe Roux, Jay; Mararakanye, Ndifelani; Van der Laan, Michael; Mudaly, Leushantha; Weepener, Harold Louw; Van Tol, Johan (Elsevier, 2025-06)STUDY REGION : South Africa. STUDY FOCUS : The focus of the study is to develop soil, land cover and weather generator file datasets for Soil and Water Assessment Tool (SWAT) applications in South Africa. The first objective was to format national datasets for use as baseline to run the SWAT model in South Africa. The second objective was to evaluate the performance of the baseline input data by applying the national datasets in four (previously simulated) research catchments. NEW HYDROLOGICAL INSIGHTS FOR THE REGION : The input datasets comprise of geo-spatial datasets at a national scale to run ArcSWAT or QSWAT (graphical user interface for SWAT in ArcGIS and SWAT+ in QGIS, respectively) in South Africa including: SWAT catchment outline data (tertiary and quaternary); Land cover maps at 20–30 m resolution including South African National Land Cover (2014, 2018, 2020) linked to SWAT land cover codes; A soil map with SWAT attribute data derived from pedotransfer functions of the Land Type Database of South Africa useable at a scale of 1:250,000; Weather statistics (WGN) files for 12 weather stations obtained from the Agricultural Research Council in South Africa. The national baseline data is an important step forward in hydrological modelling by assisting modellers to set-up and run the SWAT model in South Africa.Item Macrofauna-environment interactions and their potential in restoring degraded landscapes in the context of Sub-Saharan Africa : a review of current knowledgeKasimbo, Mukanzala; Johnson, Todd; Mwamba, Theodore M.; Uwimbabazi, Agnes; Syampungani, Stephen (Elsevier, 2025-12)Restoring degraded landscapes, such as those induced by mining activity, is essential for recovering lost ecosystem services. This requires innovative nature-based solutions, especially in sub-Saharan Africa (SSA). This review summarizes current knowledge on soil macrofauna in degraded SSA landscapes, an otherwise overlooked component of ecological restoration. A systematic literature review was conducted, yielding 31 relevant publications that were analyzed to identify patterns in macrofauna assemblages across land-use types in SSA including agricultural, forest, bushland, grassland, savannah, dumpsite and reclaimed mine site landscapes. Bibliometric analysis showed minimal studies before 2014, with research increasing after 2017, mostly in southern and eastern Africa. West Africa remains underrepresented. We found more studies on agricultural systems type (28 of the 32 reviewed studies), reporting seven classes, while less studies were conducted on mining wasteland (3 of 31 reviewed studies) reporting only one class. This highlights the urgent need for more macrofauna research in mine wastelands to pursue restoration. Variations in macrofauna composition (at both class and order level) are also viewed in relation to their physiological and environmental plasticity adaptations. In addition, potential macrofauna functional roles, such as bioturbation, organic matter breakdown, nutrient cycling, as well as other attributes such as tolerance to harsh environments and bioindication of biodiversity recovery, that may support landscape restoration were considered as well. Macrofauna groups with potential in future bioaugmentation strategies (the deliberate introduction of beneficial soil organisms to enhance ecological functions) include earthworms (Oligochaeta), termites (Isoptera) and ants (Hymenoptera: Formicidae). Opportunities and challenges of their integration into restoration planning are also discussed, especially in the context of SSA mining landscapes, which are often characterized by severe ecological degradation such as surface water contamination and heavy metal pollution. Although there is a gradual increase in publications on macrofauna in Southern Africa, their practical inclusion in ecological restoration efforts across SSA remains limited. The lack of a better understanding of macrofauna tolerance mechanisms, particularly to environmental stressors such as temperature fluctuations, chemical pollution, and habitat alterations, and the precise nature of their interactions with both biotic and abiotic environmental factors is identified as an avenue for future investigations. HIGHLIGHTS • Macrofauna-environment interactions towards eco-restoration in SSA are reviewed. • Profiles of reported macrofauna groups and key environmental factors are discussed. • West Africa is the least represented sub-region in reviewed papers. • Macrofauna profile in mine wastelands is scantily documented. • Macrofauna bioremediation potential is underexplored, hampered by limited knowledge.Item A systematic review of vegetation indices for potato growth monitoring and tuber yield prediction from remote sensingMukiibi, Alex; Machakaire, Allan Tatenda Batsirai; Franke, A.C.; Steyn, Joachim Marthinus (Springer, 2025-03)Crop intelligence and yield prediction of potato (Solanum tuberosum L.) are important to farmers and the processing industry. Remote sensing can provide timely information on growth status and accurate yield predictions during the growing season. However, there is limited documentation on the most suitable vegetation indices (VIs) and optimal growth stages for acquiring remote sensing imagery of potato. To address this knowledge gap, a systematic review was conducted. Original scientific manuscripts published between 2000 and 2022 were identified using various databases. The findings indicate that satellite imagery is the most widely used source of remote sensing data for tuber yield prediction, whereas unmanned aerial vehicle systems (UAVs) and handheld sensors are more frequently applied for growth monitoring. The normalized difference vegetation index (NDVI), red-edge chlorophyll index (CIred-edge), green chlorophyll index (CIgreen), and optimized soil-adjusted vegetation index (OSAVI) are the most frequently used VIs for the growth and yield estimation of potato. The tuber initiation stage was found to be the most appropriate stage for remote sensing data acquisition. This review will assist potato farmers, agronomists and researchers in selecting the most suitable VIs for monitoring specific growth variables and selecting the optimal timing during the growing season to obtain remote sensing images.Item Establishing the host status of various cover and rotation crop species to the soil‑borne pathogen, Spongospora subterranea f. sp. subterranea, in South AfricaStrydom, R.F.; Van der Waals, Jacqueline Elise (Springer, 2025-07-15)Spongospora subterranea f. sp. subterranea (Sss) is the causal agent of the potato tuber disease, powdery scab. Sss infects a wide range of species, often used for cover cropping or as rotation crops. These alternative hosts are classified into several host types based on the presence of specific Sss pathogenic structures within their roots. True hosts produce sporosori that could contribute to the soil inoculum, whilst trap crops prevent Sss from completing its life cycle. This study investigated the Sss host status of various crops using a combination of bioassays and microscopic root assessments for pathogen detection, and molecular techniques for infection confirmation. Sss DNA was detected in all 26 species evaluated, and these were subsequently classified as alternative hosts of Sss. Most species assessed were identified as true hosts. Brassica alba, Chloris gayana, and Cucurbita moschata were the only species in which only the zoosporangial life cycle phase was noted and were classified as potential trap crops. Several species identified in the literature as trap crops and non-hosts were reclassified based on the results of this study. Additional research and field trials are required to determine the importance of the host status of rotation crops on Sss soil inoculum.Item Acmadenia kamdeboo (Rutaceae: Diosmeae) - a new species endemic to the Kamdebooberge, Sneeuberg Massif (Eastern Cape, South Africa)Clark, V. Ralph; De Deus Jr, Joao; Barker, Nigel (Elsevier, 2026-01)Acmadenia Bartl. & H.L. Wendl. (Rutaceae: Diosmeae) is a genus of 33 aromatic shrub species, which—with the exception of at least three species—is endemic to the Core of the Greater Cape Floristic Region and contributes to the exceptional richness of the Core of the Greater Cape Floristic Region, which is also part of a biodiversity hotspot. We describe the 34th known species, A. kamdeboo V.R. Clark & J.D. Vidal—a narrow endemic confined to the Kamdebooberge (Camdeboo Mountains) in the south-western Sneeuberg massif, near Aberdeen (Eastern Cape, South Africa). Morphologically, it is closest to A. sheilae I. Williams, but differs by the smaller, obovate-lanceolate leaves; alternate phyllotaxy; adpressed to patent leaf insertion; shorter sepals and bracts; and a rounded apical anther gland. Also, Acmadenia kamdeboo occurs primarily on Karoo Supergroup dolerites—rather than on Cape Supergroup sandstones. Acmadenia kamdeboo contributes to a local node of endemism in the western Sneeuberg—including the other, highly localised Kamdebooberge endemic Faurea recondita Rourke & V.R. Clark—and is the only Acmadenia found north of the Great Karoo, on the Great Escarpment. Acmadenia kamdeboo is the second Eastern Cape endemic in the genus—both being in summer/bimodal autumn–spring climates—out of three species recorded in the province. The Kamdebooberge deserves further botanical exploration and may contain further novelties. HIGHLIGHTS • A new species of Acmadenia is described from the Eastern Cape, South Africa. • The new species is endemic to the Kamdebooberge, Sneeuberg. • This is the first species of Acmadenia found on the Great Escarpment. • The species is recommended as South African Red Category of Rare.Item Predicting persistent forest fire refugia using machine learning models withtopographic, microclimate, and surface wind variablesChrist, Sven; Kraaij, Tineke; Geldenhuys, Coert Johannes; De Klerk, Helen M. (MDPI, 2025-12)Persistent forest fire refugia are areas within fire-prone landscapes that remain fire-free over long periods of time and are crucial for ecosystem resilience. Modelling to develop maps of these refugia is key to informing fire and land use management. We predict persistent forest fire refugia using variables linked to the fire triangle (aspect, slope, elevation, topographic wetness, convergence and roughness, solar irradiation, temperature, surface wind direction, and speed) in machine learning algorithms (Random Forest, XGBoost; two ensemble models) and K-Nearest Neighbour. All models were run with and without ADASYN over-sampling and grid search hyperparameterisation. Six iterations were run per algorithm to assess the impact of omitting variables. Aspect is twice as influential as any other variable across all models. Solar radiation and surface wind direction are also highlighted, although the order of importance differs between algorithms. The predominant importance of aspect relates to solar radiation received by sun-facing slopes and resultant heat and moisture balances and, in this study area, the predominant fire wind direction. Ensemble models consistently produced the most accurate results. The findings highlight the importance of topographic and microclimatic variables in persistent forest fire refugia prediction, with ensemble machine learning providing reliable forecasting frameworks.Item Utility of UAS-LIDAR for estimating forest structural attributes of the Miombo woodlands in ZambiaShamaoma, Hastings; Chirwa, Paxie W.; Zekeng, Jules C.; Ramoelo, Abel; Hudak, Andrew T.; Handavu, F.; Syampungani, Stephen (Public Library of Science, 2025-03-11)The ability to collect precise three-dimensional (3D) forest structural information at a fraction of the cost of airborne light detection and ranging (lidar) makes uncrewed aerial systems-lidar (UAS-lidar) a remote sensing tool with high potential for estimating forest structural attributes for enhanced forest management. The estimation of forest structural data in area-based forest inventories relies on the relationship between field-based estimates of forest structural attributes (FSA) and lidar-derived metrics at plot level, which can be modeled using either parametric or non-parametric regression techniques. In this study, the performance of UAS-lidar metrics was assessed and applied to estimate four FSA (above ground biomass (AGB), basal area (BA), diameter at breast height (DBH), and volume (Vol)) using multiple linear regression (MLR), a parametric technique, at two wet Miombo woodland sites in the Copperbelt province of Zambia. FSA were estimated using site-specific MLR models at the Mwekera and Miengwe sites and compared with FSA estimates from generic MLR models that employed combined data from the two sites. The results revealed that the model fit of site-specific MLR models was marginally better (Adj-R2: AGB = 0.87–0.93; BA = 0.88–0.89; DBH = 0.86–0.96; and Vol = 0.87–0.98 than when using a generic combined data model (AGB = 0.80; BA = 0.81; DBH = 0.85; and Vol = 0.85). However, the rRMSE (2.01 – 20.89%) and rBias (0.01-1.03%) of site specific MLR models and combined data model rRMSE (3.40-16.71%) and rBias (0.55-1.16%) were within the same range, suggesting agreement between the site specific and combined data models. Furthermore, we assessed the applicability of a site-specific model to a different site without using local training data. The results obtained were inferior to both site-specific and combined data models (rRMSE: AGB = 36.29%–37.25%; BA = 52.98–54.52%; DBH = 55.57%–64.59%; and Vol = 26.10%–30.17%). The results obtained from this indicate potential for application in estimating FSA using UAS-lidar data in the Miombo woodlands and are a stepping stone towards sustainable local forest management and attaining international carbon reporting requirements. Further research into the performance of UAS-lidar data in the estimation of FSA under different Miombo vegetation characteristics, such as different age groups, hilly terrain, and dry Miombo, is recommended.Item Seasonal spatial-temporal trends of vegetation recovery in burned areas across AfricaMaillard, Oswaldo; Ribeiro, Natasha; Armstrong, Amanda; Ribeiro-Barros, Ana I.; Macrice Andrew, Samora; Amissah, Lucy; Shirvani, Zeinab; Muled, Jonathan; Abdi, Omid; Azurduy, Huascar; Silva, João M.N.; Syampungani, Stephen; Shamaoma, Hastings; Buramuge, Victorino (Public Library of Science, 2025-02-03)Africa is entering a new fire paradigm, with climate change and increasing anthropogenic pressure shifting the patterns of frequency and severity. Thus, it is crucial to use available information and technologies to understand vegetation dynamics during the post-fire recovery processes. The main objective of this study was to evaluate the seasonal spatio-temporal trends of vegetation recovery in response to fires across Africa, from 2001 to 2020. Non-parametric tests were used to analyze MODIS Normalized Difference Vegetation Index (NDVI) products comparing the following three-month seasonal periods: December-February (DJF), March-May (MAM), June-August (JJA), and September-November (SON). We evaluated the seasonal spatial trends of NDVI in burned areas by hemisphere, territory, or country, and by land cover types, and fire recurrences, with a focus on forested areas. The relationships between the seasonal spatial trend and three climatic variables (i.e. maximum air temperature, precipitation, and vapor pressure deficit) were then analyzed. For the 8.7 million km2 burned in Africa over the past 22 years, we observed several seasonal spatial trends of NDVI. The highest proportions of areas with increasing trend (p < 0.05) was recorded in MAM for both hemispheres, with 22.0% in the Northern Hemisphere and 17.4% in the Southern Hemisphere. In contrast, areas with decreasing trends (p < 0.05), showed 4.8–5.5% of burned area in the Northern Hemisphere, peaking in JJA, while the Southern Hemisphere showed a range of 7.1 to 10.9% with the highest proportion also in JJA. Regarding land cover types, 48.0% of fires occurred in forests, 24.1% in shrublands, 16.6% in agricultural fields, and 8.9% in grasslands/savannas. Consistent with the overall trend, the area exhibiting an increasing trend in NDVI values (p < 0.05) within forested regions had the highest proportion in MAM, with 19.9% in the Northern Hemisphere and 20.6% in the Southern Hemisphere. Conversely, the largest decreasing trend (p < 0.05) was observed in DJF in the Northern Hemisphere (2.7–2.9%) and in JJA in the Southern Hemisphere (7.2–10.4%). Seasonally, we found a high variability of regeneration trends of forested areas based on fire recurrences. In addition, we found that of the three climatic variables, increasing vapor pressure deficit values were more related to decreasing NDVI levels. These results indicate a strong component of seasonality with respect to fires, trends of vegetation increase or decrease in the different vegetation covers of the African continent, and they contribute to the understanding of climatic conditions that contribute to vegetation recovery. This information is helpful for researchers and decision makers to act on specific sites during restoration processes.Item Remote sensing applied in land use and land cover change (LUCC) in arid and semi-arid ecosystems : current status, challenges and prospects – a systematic reviewAgassounon, Bill M.; Assede, Emeline Sessi Pelagie; Bastin, Jean-Francois; Biaou, S.S. Honore (Springer, 2025-10)Arid and semi-arid ecosystems face a triple environmental threat at the intersection of climate change, biodiversity loss, and desertification. Land use and land cover change (LUCC) in the region is, therefore, a key indicator in monitoring overall ecosystem health. However, persistent challenges hinder LUCC assessment in dry biomes, notably due to the heterogeneity of arid vegetation and its response to high temperature and water availability variations throughout the year. To identify the most important knowledge gaps easily tackled in the near future, this systematic review synthesizes current scientific knowledge on LUCC monitoring in arid and semi-arid ecosystems from the Scopus and Dimensions databases. Study results showed that seasonality (41%) and spatial resolution (28%) were the two main factors limiting LUCC in arid and semi-arid ecosystems. These factors had a significant influence on map accuracy, particularly due to seasonal variations in vegetation and the conditions under which satellite images were taken. Classification accuracy decreased substantially when the studies attempted to describe vegetation classes in more detail. Reported classification accuracies in the literature (accuracy ≥ 80%) reflected overconfidence, as a large proportion of the publications (70%) were limited to general distinctions such as forest and non-forest, without tackling more complex categories. Thus, given the importance of global vegetation maps for ecosystem management, a valuable tool for forest management and environmental planning, wrong estimation can introduce biases, leading to inappropriate management decisions and thus compromising the sustainability of natural resources and the ecosystem services that depend on them.