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Patterns of mature woody plant species encroachment on vegetation structure, density, and diversity of the understory layer across the Marikana Thornveld
(Frontiers Media, 2025-05) Mangwane, Mziwanda; Madakadze, Ignacio Casper; Tjelele, Tlou Julius; Ramoelo, Abel; u14387027@tuks.co.za
INTRODUCTION : Bush encroachment has a negative impact on the vegetation structure, ecosystem functions, and services of savanna rangelands. Woody plant encroachment creates an imbalance in the grass-to-tree ratio, leading to a decline in ecosystem services, including grazing capacity and soil nutrients.
METHODS : This study aimed to evaluate the vegetation structure, diversity, and relationships of tree species across four different growth stages in the Marikana Thornveld. Three sites were identified at the Roodelpaat experimental farm, where six 1-hectare plots were established. In each plot, nine 10 m × 10 m subplots were set up to identify mature woody plants, shrubs, and saplings. Seedlings were identified within three 1.69 m² quadrats nested within each subplot.
RESULTS AND DISCUSSION : The study identified a total of 9,028 individual woody plants, including 158 seedling species, 161 saplings, 159 shrubs, and 154 mature woody plant species. The regression line plotted seedling density against the densities of mature trees, shrubs, and saplings, with b values significantly less than 1, indicating a negative impact of mature trees, shrubs, and saplings on the seedling layer. Seedling abundance displayed a non-linear relationship with mature trees, indicating a 4.75% representation of seedling abundance within the mature tree layer. Woody seedling species exhibited the highest abundance across four growth stages. Overall, across all woody plant species at different growth stages, there was a general decline in the woody density class, resulting in a J-shaped curve pattern. Seedlings and mature trees exhibited the highest diameter at breast height (dbh) proportions among individual woody plants from the first to the third DBH size classes, followed by a decline.
CONCLUSION : Generally, these results highlight a weak relationship between mature woody plant species and the understory layer, including shrubs, saplings, and seedlings. Consequently, mature woody plants cannot predict the establishment of understory woody plants or the recruitment of seedlings as a cause of bush encroachment.
The development of a CBT-informed approach to supporting type 2 diabetes self-management
(Frontiers Media, 2025-02) Visagie, Elne; Deacon, Elmari; Kok, Rumando; elne.visagie@up.ac.za
BACKGROUND : The self-management of adults with type 2 diabetes proves to be a continuous challenge. Within the South African context, socio-economic disparities, unequal access to healthcare and varying healthcare beliefs augment these challenges. CBT is a time-sensitive and structured intervention that has been effectively implemented for chronic diseases. CBT has been employed to improve psychological outcomes in adults with type 2 diabetes, but there is limited research on how this therapeutic intervention can enhance self-management outcomes of type 2 diabetes. Adaptable CBT-based interventions are needed to promote a holistic approach to type 2 diabetes self-management and empower a broader range of healthcare professionals to provide targeted interventions. Flexible interventions can promote patient engagement and be integrated into various healthcare settings where patients already access services.
METHOD : The study employed document analysis to develop CBT-informed guidelines. Data was analysed by means of content analysis. Two research studies formed the dataset, and categories and subcategories were identified. The categories were integrated and used to develop the CBT-informed guidelines.
RESULTS : These guidelines were based on core CBT components and divided into the introduction, working, and consolidation phases. The guidelines specified the roles of healthcare practitioners who would implement them and provided skills and techniques for healthcare professionals and patients within each phase.
CONCLUSION : The CBT-based interventions aimed to provide a tool for healthcare practitioners and patients in terms of flexibility, accessibility, and personalisation.
Simulation of the African ITCZ during austral summer seasons and ENSO phases : application of an RCM derived from stretched grid ESM
(Frontiers Media, 2025-07) Ramotubei, Teke Solomon; Landman, Willem Adolf; Mateyisi, Mohau J.; Nangombe, Shingirai S.; Beraki, Asmerom Fissehatsion
INTRODUCTION : Climate predictability across timescales in a changing climate presents a unique opportunity and challenges for state-of-the-art climate models. The use of regional climate models (RCMs) forced with interactively coupled Earth System Models (ESMs) for the sub-seasonal, seasonal, and decadal predictions is an actively growing research area.
METHODS : The study explores a stretched-grid RCM constrained with an ESM which integrates a climate change signature. Spectral relaxation paradigm is applied to limit the climate drift within the range of the multi-model sea-surface temperature (SST) and sea-ice concentration (SIC) variability. The model retroactive ensemble simulations for November initialization are evaluated on the seasonal migration of the ITCZ during El-Niño and La-Niña phases, exploring both the spatial and zonal positions. The model is also evaluated on the ITCZ process’ characteristics that include the Hadley cell (HC), stream function and the subtropical jet stream (STJ) using quantitative methods.
RESULTS : The RCM and the driving ESM demonstrate skillful performance in identifying the seasonal trajectory of both the spatial and zonal migration of the ITCZ during El-Niño and La-Niña. Moreover, the RCM also demonstrates a good skill in determining both the descending edge of the HC and the STJ with the highest mean percentage error of 16.3 and 7.5% for the HC and STJ latitudes, respectively.
CONCLUSIONS : The November initialization of the RCM skillfully simulates the seasonal migration of the ITCZ (and related characteristics) aligned to the observations and reanalysis datasets. Notwithstanding, the RCM manifests a tendency of more dynamic error growth relative to its driving ESM as the lead time increases. Furthermore, the RCM is also out of phase with a southerly shift of the stream function compared to the 500 hPa reanalysis stream function. The modeling framework offers process oriented and teleconnection studies. It also provides great potential for climate applications with suitable bias corrections techniques, albeit the source and mechanism of its dynamic error growth deserve further investigation.
Research progress on climate change adaptation strategies to control invasive crop pest in sub-Saharan Africa : a bibliometric and systematic review
(Frontiers Media, 2025-02) Assede, Emeline Sessi Pelagie; Othoo, Calvince Ouko; Ly, Ahmadou; Bayisa, Gobena; Tarkegn, Temesgen Gashaw; Zohoun, Megnisse; N'goran, Anje-Jokebed
This bibliometric and systematic review assesses research progress and climate change adaptation strategies to control invasive crop pests in sub-Saharan Africa. Scientific publications on crop pest management in sub-Saharan Africa in a context of climate change adaptation were extracted from papers published between 1991 and 2024. A literature search was conducted on Scopus, dimension, and google scholar, followed by screening and data extraction in compliance with ROSES standards. Findings indicated that pests such as armyworms, fruit flies and coffee berry borer cause huge losses. Communities are adopting integrated pest management, water harvesting, drip irrigation, resistant varieties, and improving production efficiency. Agro-ecological practices reduce pest invasions while preserving the environment. Meanwhile, chemical insecticide use remains an emergency solution as its effects on pest control would be more efficient. However, promising approaches emerge around biocontrol, agroforestry integrating pest management, and gender-tailored strategies. Nevertheless, regional disparities persist in scientific output. In conclusion, while invasive pests represent a major plant health crisis in sub-Saharan Africa, this review highlights innovative adaptation strategies. Their development will require coordinated mobilization to catalyze the sustainable agro-ecological transition that sub-Saharan Africa needs to address these multidimensional challenges. Future research should assess farmer’s perception on the effectiveness of the existing pest management practices for invasive crop pests.
Multisystemic resilience and its impact on youth mental health : reflections on co-designing a multi-disciplinary, participatory study
(Frontiers Media, 2025-03) Theron, Linda C.; Bergamini, Matteo; Chambers, Cassey; Choi, Karmel; Fawole, Olufunmilayo I.; Fyneface, Fyneface Dumnamene; Höltge, Jan; Kapwata, Thandi; Levine, Diane T.; Mai Bornu, Zainab; Makape, Makananelo; Matross, Celeste; McGrath, Brian; Olaniyan, Olanrewaju; Stekel, Dov J.; Hey, Josh Vande; Wright, Caradee Yael; Zion, Ameh Abba; Ungar, Michael; linda.theron@up.ac.za
Youth depression is a global emergency. Redressing this emergency requires a sophisticated understanding of the multisystemic risks and biopsychosocial, economic, and environmental resources associated with young people's experiences of no/limited versus severe depression. Too often, however, personal risks and a focus on individual-level protective resources dominate accounts of young people's trajectories towards depression. Further, studies of depression in high-income countries (i.e., “western”) typically inform these accounts. This article corrects these oversights. It reports on the methodology of the Wellcome-funded R-NEET study: a multidisciplinary, multisystemic, mixed method longitudinal study of resilience among African youth whose status as “not in education, employment or training” (NEET) makes them disproportionately vulnerable to depression. Co-designed by academics, community-based service providers and youth in South Africa and Nigeria, with partnerships in the United Kingdom, Canada and the United States, the R-NEET study is identifying the physiological, psychological, social, economic, institutional, and environmental risks and resources associated with distinct trajectories of depression. Using the methodology of the R-NEET study as exemplar, this article advances an argument for understanding resilience as a contextually and culturally rooted capacity that draws on the multiple, co-occurring systems that young people depend upon to support their wellbeing. Acknowledging and harnessing the multiple systems implicated in resilience is critical to researchers and mental health providers who seek to support young people to thrive, and to young people themselves when protecting or promoting their mental wellbeing.