Emerging Land Use Changes-Climatic Variability Nexus in Meru County, Kenya

The interplay between land use changes and climate variability are potential causes for the declining agricultural productivity in Meru County. Given that the agroecological disparities are attributable to the topography, a topo-sequence analysis of land use changes and climate variability was carried out in the major sub-agroecological zones of Meru County. Data on land use change and rainfall was triangulated with that of household survey, focused groups and in-depth interviews. Land use changes along the agroecological zones were consequently explained by various factors including climatic variability. There were marked land use changes in six of the seven major sub-Agro-ecological zones between 1976 and 2007. In low highland 1, upper midland 1, 2 and 3 and low midland 3, areas under agricultural land use increased while that under forest decreased further, in low midland 6 shrubs were replaced by rainfed crops (r² = 0.98) an indication that natural vegetation was being cleared for cultivation. Such practices constitute injurious land use and management tendencies. The upper midland zone described as coffee zone was converted into bananas as the main cotton zone (LM3) evolved to irrigated crops. There was a detrimental land use trend where area under natural vegetation decreased as cultivated area increased therefore necessitating liberation of land under other uses for forest establishment. Mitigation of negative effects of climate variability on land use which focuses on seasonal land use patterns for enhanced land use performance or productivity are imperative. The agroecological differences in rainfall variability and land use changes call for tailored interventions that target specific sub-agro ecological zones. Key terms: Topo-sequence analysis, seasonal rainfall variabilit

Toward a Hydro-Economic Approach for Risk Assessment and Mitigation Planning of Water Disasters in Semi-Arid Kenya

This study evaluates hydro-geomorphologic risks, and social and economic impacts associated with farming and water use in dry and marginal lands. Hydro-economic risk assessment offers a novel framework towards sustainable management of agricultural water in arid and semi-arid lands (ASAL). The risk assessment conducted in Muooni Dam Catchment of Kenya utilized a “hydro-economic” procedure to assess risks related to farming activity, water and land use. The process provides for mitigation planning, implementation, monitoring and evaluation of water disasters in the catchment area, focusing on effects of farming on water and land, social welfare and economic efficiency

Morphologic Response of a River Channel to Sand Mining in River Tyaa, Kitui County, Kenya

Over 40 billion tons of sand is mined worldwide every year which is estimated to be higher than the natural replacement rates. In Kenya, the rate of sand mining is raising concerns over its environmental effects since it is not regulated. This paper presents findings on the geomorphic effects of sand mining in the ephemeral River Tyaa channel in Kitui County. The study adopts the concept of feedback response mechanism of a natural geomorphic system. Through purposive sampling River Tyaa was selected for the study, where rampant sand mining was reportedly taking place. Random sampling on the five sand mining sites identified came up with a representative site namely Kanginga on which systematic sampling was applied while collecting data at both the active and control sites. Data on channel width, depth and slope angles was obtained through physical measurements while data on quantity of sand mined was obtained from Mwingi Sand Mining Cooperative. Multiple logistic regression analysis was used to analyse data whereby the model compared active and control sites. Test results indicated that sand mining had significantly increased river channel’s width (O.R. =1.531), depth (O.R. =1.527) and slope angles (O.R. =1.634) at active mining sites compared to control sites as deduced from the respective Odds Ratios. It concluded that sand mining had altered channel’s morphology resulting to adverse environmental effects such as loss of riparian vegetation and channel incision. It recommended curbing of illegal sand mining through licencing operators and reducing quantity of sand mined by closing some mines. Furthers, it recommended monitoring through regular Environmental Impact Assessment (E.I.A) and Audit (E.A) to inform protection of the river system from degrading

Medicinal service supply by wild plants in Samburu, Kenya: Comparisons among medicinal plant assemblages

Supply of medicinal plants from African landscapes is crucial because of their widespread use. Rapid climate change and land use change are potential threats to this resource but knowledge about the ecological needs of many of these plants is still rather limited. More knowledge about potential threats to medicinal plants supply and options to prevent future losses are desirable. Therefore, the objectives of the study were to examine (1) the effects of environmental drivers on the occurrence of medicinal plant species, (2) how different vegetation formations contribute to the provision of plants used for the treatment of diseases and (3) how these contributions are secured by redundancy. The analysis was based on a sample of 130 sampling plots in Samburu County, Kenya. We identified patterns in medicinal plants co-occurrences using classification and ordination analyses and analyzed these pattern in terms of environmental drivers, service diversity and service security. The pattern in medicinal plants co-occurrences reflected the distribution of broad formations (bushed grassland, forest, wooded grassland, savanna) driven by differences in grazing pressure, drought, slope and fraction of sand in soils. Each of the formations brought with it its own characteristic endowment with medicinal plants. The formations differed in the diversity and security of medicinal services provided. All resulted as fulfilling unique services with diseases treated by plants occurring exclusively in one or another formation. Forests featured the highest diversity of medicinal services, with medicinal plants used against 67 diseases. The supply security in forests, resulting from redundancy in supply provision, was moderate. In contrast to this, savanna grasslands featured plants with uses against 49 diseases, some of them were treated exclusively by plants from savanna grasslands. This formation also showed the highest redundancy. Wooded grasslands showed very little redundancy and is likely to be adversely affected by climate change. Whereas savannas feature the largest pool of medicinal plants and should receive due attention, urgent and highest conservation priority should, presently and in future, go towards the wooded grassland that had the lowest supply redundancy for traditional medicine

Climate change impacts on the availability of anti-malarial plants in Kenya

In many rural East African areas, anti-malarial plants are commonly used as first-line treatment against malaria. However, spatially explicit information about the future availability of anti-malarial plant species and its relation to future suitable habitat for malaria vectors is limited. In this study we (1) model the distribution of anti-malarial plant and malaria vector species and assess the drivers of their distributions taking the example of the Samburu dryland in Kenya, (2) map the modeled overlap in this area, (3) assess the impact of future climate change on anti-malarial plant and malaria vector species and (4) report their future overlaps. Our results show that mean temperature of warmest quarter, precipitation of wettest quarter and mean temperature of coldest quarter were the most important environmental variables that affected the distribution of anti-malarial species. The effects of climate change will vary, with some areas characterized by huge losses in anti-malarial species habitat while others gained or remained stable under both SSP2-4.5 and SSP5-8.5 climate change scenarios by 2050s and 2070s. According to most of our scenarios, more than half of the anti-malarial species will become vulnerable or threatened by 2050s and 2070s. A comparison between distribution patterns of future anti-malarial species richness and malaria vector species suitable habitat suggests that the former will decrease considerably while the later will increase. Because the availability of anti-malarial species will decrease in the areas affected by malaria vectors, geographically targeted conservation strategies and further control measures against malaria vectors are all the more important

Impact of Climate and Land Use/Land Cover Change on the Water Resources of a Tropical Inland Valley Catchment in Uganda, East Africa

The impact of climate and land use/land cover (LULC) change continues to threaten water resources availability for the agriculturally used inland valley wetlands and their catchments in East Africa. This study assessed climate and LULC change impacts on the hydrological processes of a tropical headwater inland valley catchment in Uganda. The hydrological model Soil and Water Assessment Tool (SWAT) was applied to analyze climate and LULC change impacts on the hydrological processes. An ensemble of six regional climate models (RCMs) from the Coordinated Regional Downscaling Experiment for two Representative Concentration Pathways (RCPs), RCP4.5 and RCP8.5, were used for climate change assessment for historical (1976-2005) and future climate (2021-2050). Four LULC scenarios defined as exploitation, total conservation, slope conservation, and protection of headwater catchment were considered. The results indicate an increase in precipitation by 7.4% and 21.8% of the annual averages in the future under RCP4.5 and RCP8.5, respectively. Future wet conditions are more pronounced in the short rainy season than in the long rainy season. Flooding intensity is likely to increase during the rainy season with low flows more pronounced in the dry season. Increases in future annual averages of water yield (29.0% and 42.7% under RCP4.5 and RCP8.5, respectively) and surface runoff (37.6% and 51.8% under RCP4.5 and RCP8.5, respectively) relative to the historical simulations are projected. LULC and climate change individually will cause changes in the inland valley hydrological processes, but more pronounced changes are expected if the drivers are combined, although LULC changes will have a dominant influence. Adoption of total conservation, slope conservation and protection of headwater catchment LULC scenarios will significantly reduce climate change impacts on water resources in the inland valley. Thus, if sustainable climate-smart management practices are adopted, the availability of water resources for human consumption and agricultural production will increase

Diversity of medicinal plants and anthropogenic threats in the Samburu Central Sub-County of Kenya

Background: Traditional herbal medicine has been a constant source of substances for curing and preventing a variety of ailments. Biodiversity of medicinal plants and effects of human activities on availability of traditional herbal medicine have continuously received just a cursory treatment. This study sought to determine the biodiversity of medicinal plants and evaluate the effects of human activities on availability of traditional herbal medicine among the Samburu pastoral community in Kenya. Materials and Methods: A questionnaire survey was addressed to 195 randomly stratified household respondents in four villages in Samburu Central Sub-county. Transect walks were carried out in the four villages to determine the diversity of the medicinal plants. Voucher specimens of the medicinal plant species were deposited at Kenyatta University Herbarium. Results: The species richness comprised of 19 medicinal plants, majority of which grew in the wild but were threatened by human activities. 56% of the households reported that fire incidences highly affected availability of traditional herbal medicine, 50% reported that grazing of livestock moderately affected availability of traditional herbal medicine, 46% reported that building and construction activities moderately affected availability, while 43% and 40% reported that firewood collection and growing of crops respectively lowly affected availability of traditional herbal medicine among the Samburu people. Conclusion: Most of the Samburu people use traditional herbal medicine. However, majority of the medicinal plants are threatened by anthropogenic factors. This has led to the continued decline of traditional herbal medicine. There is, therefore need to adopt management strategies that enhance the conservation of these valuable natural resources

Odyssey of First IALE World Congress in Africa and Opportunities for North-South or South-South Collaboration

The landscape ecology community witnessed a landmark event in July 2023 as the 11th International Association for Landscape Ecology (IALE) World Congress unfolded on the African continent for the first time. This editorial commemorates this historic occasion, tracing the journey from the inception of IALE Africa initiatives in 2002 to the culmination of the World Congress in Nairobi, Kenya, almost two decades later. Having previously graced Europe, Northern America, Australia, and Asia, the IALE World Congress embraced Africa, showcasing the global reach and inclusive spirit of landscape ecology.  This editorial explores the evolution of IALE Africa, highlighting the initiatives and the persistent efforts that led to the World Congress in Africa.  We delve into the socio-cultural and international significance of this shift, emphasising the unique perspectives and challenges faced by the African landscape ecology community. In addition to recounting the narrative of the 11th IALE World Congress, we assessed the participants involved, topics discussed, current trends, and priorities within the global landscape ecology research community.  To do so, we conducted a bibliometric analysis of the conference proceedings.

Climate-proof response-capability : opportunities and challenges resulting from the implementation of green water saving schemes in Kenyan ASALs

Findings indicate the causes of vulnerability to water stress and the type of capacities of local watershed institutions to ensure successful implementation of green water savings (GWS) schemes for water and land resources management. The paper measures trends in hydro-climatic changes in Kenyan arid and semi-arid lands (ASALs). Some catchment areas are re-greening due to traditional soil and water conservation methods, even where drought patterns exist. Drip irrigation can minimize water loss by at least 30% from sprinklers, furrows and wetland diversion. Policy intervention in Kenyan ASALs should be linked to farmers’ vulnerability to drought