Browsing by Author "Karanja, Rebecca"

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    Annual Diversity of Honey Bee pollen Sources in Two Pumpkin Growing Landscapes, Machakos County, Kenya
    (Journal of Pollination Ecology, 2025-03) Nang’oni, Marystella W.; Kasina, Muo; Karanja, Rebecca; Guantai, Mary M.; Kinyanjui, Rahab N.; Omuse, Evanson R.; Lattorf, H. Michael G.; Abdel-Rahman, Elfatih M.; Adan, Marian; Mohamed, Samira A.; Dubois, Thomas
    Multi-floral foraging sources for honey bee (Apis mellifera L.) have been threatened by landscape changes and unsustainable farming practices. In East Africa, the biodiversity of forage resources that could support honey bees, especially in agricultural lands, remains least explored. This study investigated pollen diversity for honey bees in Yatta and Masinga Sub-counties in Machakos County, Kenya. Honey bee hives were installed on eight pumpkin (Cucurbita maxima Duchesne ex Lam) farms (one hive per farm) in two varying landscape vegetation classes (low and medium) based on normalized difference vegetation index (NDVI). Pollen traps were installed at the hive entrance and pollen pellets were retrieved fortnightly for subsequent identification. Approximately 115 pollen types were identified. The pollen pellets were associated with 63 plant families and 109 plant families in low and medium NDVI classes, respectively. The predominant source of pollen for honey bees in low NDVI class included the plant families Poaceae (5,526 pellets), Asteraceae (3,176 pellets), Combretaceae (1,327 pellets), Acanthaceae (1,122 pellets), Amaranthaceae (960 pellets), Boraginaceae (951 pellets), Typhaceae (889 pellets), Guaduelleae (809 pellets) and Loranthaceae (588 pellets). In medium NDVI, most pollen was sourced from plant family Asteraceae (3,605 pellets), Malvaceae (1,572 pellets), Poaceae (1,538 pellets), Combretaceae (1,468 pellets), Salvadoraceae (1,354 pellets), Solanaceae (1,011 pellets), Asphodelaceae (885 pellets), Fabaceae (882 pellets), Euphorbiaceae (685 pellets) and Myrtaceae (546 pellets). The diversity of pollen types varied between the NDVI classes and across months. Although honey bees sourced diverse pollen required for the dietary balance of the colony, there was variability across landscape types and months.
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    Cherangany Hills Forest Ecosystem Services Assessment Report, 2025
    (Nature Kenya - the East Africa Natural History Society, 2025) Muoria, Paul K.; Wabuyele, Emily; Gacheru, Paul; Ngaruiya, Grace W; Amadi, Jacinta A.; Waichoka, James; Kamau, Joseph W.; Njenga, Peninah; Karanja, Rebecca; Mutunga, James; Kimani, Julius; Lagat, Mercy Jeptum; Ruto, David; Kipruto, Caroline; Mbuvi, M.T.E.; Mwadalu, Riziki; Mwamodenyi, James M.; Mwamodenyi, James M.
    The Cherangany Hills Forest is a vital ecological resource that provides essential ecosystem services — supporting livelihoods, maintaining biodiversity, and contributing to both regional and national economies. However, this ecosystem faces mounting pressures driven by an increasing human population and the expansion of agricultural land. Other significant threats include unsustainable resource extraction, climate change, habitat loss and degradation and the spread of invasive plant species. These challenges endanger the forest’s ability to continue providing critical goods and services to communities. This ecosystem service assessment was conducted to evaluate the current value of key ecosystem services and to explore how these values might change under two contrasting future scenarios: a business-as-usual trajectory and a restoration-focused pathway. These future scenarios were informed by a parallel study that identified and mapped degraded areas within the Cherangany Hills forests that require restoration. This comprehensive report is the result of a collaborative effort, drawing on diverse expertise to capture a broad spectrum of ecosystem service values. It covers water provisioning for domestic, livestock, agricultural and hydroelectric power generation purposes, alongside the tangible benefits of harvested wild goods, crop production, carbon sequestration and the cultural significance of the forest to local communities. The report demonstrates the essential role of the ecosystem in supporting both human well being in immediate landscape and even beyond. According to the study, the restoration scenario offers significant economic benefits at local, regional, and national levels alongside numerous environmental advantages. This report contributes to the growing body of evidence supporting the case for restoring this critical ecosystem. Moreover, the findings will guide key policy and planning processes including forest management planning, County Integrated Development Plans (CIDPs), climate change strategies and other county and national-level policies. This work would not have been possible without the dedication of the research team; collaboration from project partners including Kenyatta University, Nature Kenya, Kenya Forest Research Institute, Kenya Forest Service and the National Museums of Kenya and the invaluable support of all stakeholders. We are confident that this report will inform decision-making, inspire restoration initiatives and contribute to securing the long-term resilience of the Cherangany Hills Forest.
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    Cherangany Hills Forest Restoration Opportunity Assessment and Mapping Report, 2025
    (Nature Kenya - the East Africa Natural History Society, 2025) Muoria, Paul K.; Karanja, Rebecca; Gacheru, Paul; Wabuyele, Emily; Ngaruiya, Grace; Kamau, Joseph; Amadi, Jacinter A.; Njenga, Peninah; Waichoka, James; Mbuvi, Musingo T.E.; Mutunga Joshua, James; Kimani, Julius; Lagat, Mercy; Mwamodenyi, James M.; Matiku, Paul
    The Cherangany Hills Forest ecosystem is one of Kenya’s most vital ecological landscapes, providing essential services, supporting biodiversity, and sustaining the livelihoods of bordering and downstream communities. However, the ecological integrity of this important ecosystem is threatened by deforestation, land degradation and climate change, among other challenges. This report is an outcome of a collaborative effort aimed at understanding the current state of the landscape and identifying practical, science-derived restoration opportunities. The report is organized into five chapters. Chapter 1 outlines the rationale and objectives of conducting the restoration opportunities assessment and mapping exercise for the Cherangany Hills Forest landscape. It also introduces the Restoration Opportunity Assessment Methodology (ROAM) that was used in this study. Chapter 2 presents a synthesis of the baseline conditions, identifies the key drivers of degradation, and reviews the institutional and policy frameworks that support forest restoration. In Chapter 3, the participatory assessment methods used in this study are presented, emphasizing the involvement of stakeholders. Chapter 4 highlights the key findings, including: • Land Use and Land Cover (LULC) changes from 1994 to 2023 and projections for future scenarios. • Areas identified for restoration. • Financial analyses of restoration efforts. • An evaluation of the impact of restoration on ecosystem services. • A summary of potential sources of funding for restoration efforts Chapter 5 present conclusions and actionable recommendations for stakeholders to drive the restoration process forward. Overall, this report provides a guiding framework for policymakers, conservationists, local communities, and other stakeholders to pursue targeted restoration interventions. Cherangany Hills Forest restoration journey is a shared responsibility among national and county governments, conservation agencies, local communities, and development partners. This report is a valuable resource for decision-making, supporting Kenya’s commitments to national and global environmental goals, including the Bonn Challenge, AFR100, and Sustainable Development Goals (SDGs). We extend our sincere gratitude to all stakeholders, researchers and community members who contributed their knowledge, time and insights to make this assessment a reality. We hope this report inspires action, innovation, and enduring partnerships for the restoration of Cherangany Hills Forest.
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    Impacts of selected Climate Smart Agricultural Practices on African Indigenous Vegetables in Kenyan drylands
    (African Phytosanitary Journal, 2024) Muthama, Eric; Najma, Dharani; Samita, Namikoye; Karanja, Rebecca
    Climate change has had significant impacts on the cultivation of African Indigenous Vegetables (AIVs) resulting in insufficient yields and food insecurity. African indigenous vegetables are important food crops used in combating malnutrition and food insecurity. The AIVs have the potential to provide nutrition and sustain smallholder farmers’ livelihoods. However, little is known about the impacts of ClimateSmart Agriculture Practices (CSAPs) on the yield levels in AIVs. This study was therefore conducted to evaluate the impacts of selected CSAPs on the yield levels in cowpeas (Vigna unguiculata. L) and black nightshade (Solanum nigrum. L) in Kenyan drylands. Six treatments consisting of organic manure, commercial organic fertilizers, irrigation, mulching, inorganic fertilizers and controls were used. Research plots measuring 3m by 3m were set out in a randomized complete block design and sowed with certified cowpeas seeds and well-established black nightshade seedlings. Treatments were applied at land preparation and at 7 days after crop germination. Data was collected on plant height at vegetative stage and the overall primary yield at crop maturity. Analysis of variance (ANOVA) was conducted on the quantitative data collected and analyzed using Genstat software. Post hoc analysis was carried out for significant means using Tukey’s Honest Significant Difference (HSD) test at p≤0.05. The results revealed significant differences in both the plant height and primary yield across all treatments (p≤0.05). The AIV yield levels were significantly influenced by the CSAPs products used. Plots treated with organic manure, mulching and commercial organic fertilizers had significantly higher yields. Control plots had the least amount of yields.