Ecosystems In sub-Saharan Africa Research Articles

Development of a macroinvertebrate-based biotic index to assess water quality of rivers in Niger State, North Central Ecoregion of Nigeria.

The increasing pollution of lotic ecosystems in sub-Saharan Africa, particularly in Nigeria, poses a threat to water quality, public health and biodiversity. It is therefore essential to develop appropriate tools and methods for monitoring these rivers, particularly in heavily affected areas, where these water resources are vital to the surrounding communities that are heavily dependent on them. To fill this gap, we propose to develop a multimetric index based on macroinvertebrates for the assessment of ecological quality of rivers in Niger State (NSRBI). Eighty-eight metrics were evaluated through a step-by-step statistical process (namely, range test and stability, redundancy test and relationship with abiotic variables), in which metrics that did not meet the conditions were excluded. At the end of this process, only four metrics (%Hemiptera, Diptera richness, Pielou equitability and % of very large individuals (size > 40 mm)) fulfilling all criteria were included in the index. These metrics were then scored on a continuous scale and divided into four water quality classes: "very poor", "poor", "fair" and "good". Evaluation of the performance of the index on test sites showed a correspondence of 90% between index result and environmental-based classification. Therefore, the NSRBI could be a valuable tool for monitoring and assessing the ecological conditions of rivers in Niger State and the North Central Nigeria ecoregion predominantly in urban and agricultural landscapes.

Temporal Effects on Perception of Entrepreneurial Ecosystems in Sub-Saharan Africa: Evidence from Nigeria

Purpose: The motivation for this study stemmed from inconsistent attribution of sources of business challenges by entrepreneurs at the beginning and the end of a 3-month entrepreneurship development programme. While the entrepreneurs' general perception was that Nigeria's business environment was not conducive to entrepreneurship, some opinions shifted from inadequate funding to A lack of entrepreneurial skills by the end of the training. This study uses Nigeria as a case study to investigate the role of temporal effects on entrepreneurs’ perception of entrepreneurial ecosystems in Sub-Saharan Africa. Methodology: Quantitative time series analysis was deployed to analyse variables that are representative of the elements of the entrepreneurship ecosystem within the frameworks of the autoregressive distributed lag (ARDL) and mixed data sampling (MIDAS) models. Findings: The study provides evidence that temporal effects may confound entrepreneurs’ assessment of the impact of certain entrepreneurial ecosystem elements on entrepreneurial outcomes. Originality: The study contributes to the attribution theory of entrepreneurial learning by providing evidence that temporal effects have the potential to influence entrepreneurs’ attribution of business failure and the entrepreneurial learning that may arise from there.

Phytophthora: an underestimated threat to agriculture, forestry, and natural ecosystems in sub-Saharan Africa

Phytophthora species are highly destructive plant pathogens and pose a significant threat to plants in various ecosystems, including agriculture, forest plantations, and natural environments. In sub-Saharan Africa, a total of 77 Phytophthora species have been identified and this review aims to provide an overview of the species diversity and progress of Phytophthora research in this region. Numerous important studies have been carried out in this region, contributing significantly to our understanding of Phytophthora in various research fields. However, compared to global data, the advancement of Phytophthora research in sub-Saharan Africa has been relatively slow. This is evident from the fact that some countries in the region have yet to report the presence of Phytophthora species. Thus, this review also highlights critical research gaps, particularly concerning the potential impacts of climate change, and suggests specific studies to address these gaps. The identified research studies are of utmost urgency as they not only aim to safeguard the iconic floral biodiversity of the region but also play a crucial role in enhancing the economy and ensuring food security.

STI policy and governance in Sub-Saharan Africa: Fostering actors’ interactions in research and innovation

This study investigates science, technology, and innovation (STI) policy and governance in relation to research and innovation (R&I) ecosystems in Sub-Saharan Africa (SSA). To understand the implications of STI policy and governance on R&I, the authors focus on university, industry and government actors; using the Triple Helix and National Systems of Innovation approaches as analytical frameworks to guide the study. The authors identify a range of factors hindering R&I actors’ interactions, including gaps in STI governance responsibilities and accountabilities, policymaking and structural transitions, R&I management capacity and capability gaps. Based on the findings, they propose changes to policymaking and the governance of R&I in SSA, in addition to advancing innovative approaches such as ‘resource circulation’ in the context of knowledge, research and science infrastructure scarcity. The findings provide fresh insights into STI policy and governance frameworks, fostering actors’ interactions and supporting performance improvements in research, science and innovation systems across Africa.

The role of mentoring in research ecosystems in Sub-Saharan Africa: Some experiences through the CARTA opportunity

ABSTRACT Mentoring is important for improving capacity development in population and public health research in sub-Saharan Africa. A variety of experiences have been documented since Consortium for Advanced Research Training in Africa (CARTA) admitted the first cohort in 2011. However, the experience of mentoring opportunities in CARTA has not been studied. Our study focused on the perceptions, experiences and challenges of mentoring among CARTA fellows. We adopted a descriptive design based on data collected from the fellows using an online semi-structured questionnaire. Out of 143 fellows in the programme, a total of 52 fellows from seven cohorts completed the questionnaire. Fifty-three percent of the respondents were females, more than half belonged to the health sciences while 35% were in the social sciences. Fellows received mentoring from CARTA graduates and experienced researchers in the CARTA network, but they also engaged in peer-mentoring with one another. Teaching, publishing, conference attendance and grant application were considered particularly important in mentoring, but mentors and mentees highlighted personal and social issues such as networking, work-family life balance, and managing stress and time, as challenges. There is a need for more formalised but flexible mentorship initiative in the CARTA fellowship to facilitate enduring relationships for career development.

Aboveground biomass allocation, additive biomass and carbon sequestration models for Pterocarpus erinaceus Poir. in Burkina Faso

Efforts to develop allometric models for accurate estimation of biomass and carbon sequestration in Sub-Saharan African savanna ecosystems remain inconclusive. Most available allometric models are not site-specific, and hence do not account for the effects of regional climate variabilities on tree growth and capacity to sequester carbon. In contrast, site-specific biomass allometric models constitute a robust tool for forest and carbon emission management in the context of the reducing emissions from deforestation and degradation program (REDD+). Although site-specific models have been developed for several tropical tree species, such models do not exist for Pterocarpus erinaceus in Burkina Faso. In this study, we investigated biomass fraction patterns and used a system of additive allometric models for predicting aboveground biomass and carbon stocks of P. erinaceus components. Thirty P. erinaceus trees were destructively sampled to estimate the biomass of their stems, branches and leaves. The biomass fraction of each component was assessed and its relationship with tree diameter at breast height (dbh) examined. The best allometric equations of the tree components, selected from three non-linear models with dbh, height (ht) and crown diameter (Cd) as predictors, were combined to develop an additive allometric model, using the Seemingly Unrelated Regressions (SUR) method. The Ash method was then used to estimate the carbon content of the different components. Leaf and stem biomass fractions decreased when the dbh increased, whereas a reverse trend was observed for branch biomass. Dbh was the most correlated independent variable with all biomass components. AGB = e−3.46(dbh)1.62+e−2.45(dbh)2.31+e−2.68(dbh) was the most appropriate additive allometric equation for estimating the biomass of P. erinaceus trees. The carbon content of the leaves, branches and stems was 55.73%, 56.68% and 56.23%, respectively. The developed allometric equations can be used to accurately estimate the aboveground biomass of P. erinaceus in the savannas of Burkina Faso and other similar ecosystems in Sub-Saharan Africa.

Bio-herbicide potential of naturalised Desmodium uncinatum crude leaf extract against the invasive plant species Parthenium hysterophorus

The exotic plant Parthenium hysterophorus is rapidly invading ecosystems in sub-Saharan Africa, with negative effects on the environment, economy and human and animal health. With the exception of some synthetic herbicides, none of the available management methods have been effective against P. hysterophorus, and carry risks to the environment. Therefore, additional management methods must be explored for an effective integrated approach. Despite the fact that bio-herbicides are considered cost-effective and eco-friendly in mitigating biological invasions, little work has been done to utilize them for controlling P. hysterophorus. We investigated allelopathic effects and, thus, bio-herbicide potential of naturalised Desmodium uncinatum leaf (DuL) crude extract in various concentrations to control P. hysterophorus. Our results revealed that DuL crude extract can suppress P. hysterophorus, particularly at higher concentrations. The 75% and 100% DuL crude extract concentrations reduced the total leaf chlorophyll content by 26% and 22% in pots and plots, respectively. Further, these higher concentrations inhibited P. hysterophorus seed germination by 73% in petri dishes, 60% in pots, and 57% in plots, and negatively interfered with seedling growth vigour. Seedling stem heights under 75% and 100% DuL concentrations in pot and plot experiments was about 30% and 36% shorter than those sprayed with lower concentrations (< 70%) and the control, respectively. We show that naturalised plants with allelochemicals can be used as a management tool for controlling P. hysterophorus infestations in sub-Saharan Africa, particularly in Tanzania, and this method should become part of an integrated control toolkit being deployed in a community-based approach.

Delayed or early sowing: Timing as parasitic weed control strategy in rice is species and ecosystem dependent

Parasitic weeds are a severe problem in rain-fed rice production ecosystems in sub-Saharan Africa. In this study, effects of sowing time of rice on parasitic weed infection and crop yields were investigated. Field experiments were conducted in Striga asiatica-infested upland and Rhamphicarpa fistulosa-infested lowland systems from 2012 to 2014 in Kyela district, Tanzania. In each system, three rice varieties were planted at five sowing times, the first coinciding with the start of the rainy season and the four other ones followed each at two weeks’ intervals. The chosen rice varieties were the late maturing local varieties Supa India (upland and lowland) and Mwangulu (upland) and earlier-maturing NERICA-14 (upland), NERICA-L-20 (lowland) and IR64 (lowland) as alternatives. A greenhouse pot-experiment was conducted in Wageningen, the Netherlands, combining staggered planting of rice at two weeks’ intervals with introduction of either S. asiatica or R. fistulosa at one moment in time. In both field and pot experiments sowing time influenced parasite growth and rice grain yield, but the direction of these effects differed considerably between weed species and associated agro-ecosystems. In upland, S. asiatica number and biomass decreased with a delay in sowing time. It was postulated that with these delays an increasing share of the S. asiatica seed population would return to a state of dormancy from where they are unable to germinate. Under conditions of heavy infection (2013) rice yields were highest at later sowing dates. Under moderate S. asiatica infection levels (2012 and 2014) the positive effects of late sowing on rice yield were annihilated, due to increased chances of drought stress during kernel filling. This risk was mitigated by the use of an improved early-maturing variety (NERICA-14). In lowland, there was a significant increase in R. fistulosa biomass with delayed sowing times. Planting rice before optimum soil moisture conditions (i.e. saturation) for R. fistulosa seed germination are met, would result in partial escape from infection by this facultative parasite, and consequently higher rice grain yields. Manipulating rice-sowing time is a feasible control strategy to minimize parasitic weed infection, but the proper application and associated risk of this practice are strongly species and ecosystem dependent.

Sustainability in the Food-Water-Ecosystem Nexus: The Role of Land Use and Land Cover Change for Water Resources and Ecosystems in the Kilombero Wetland, Tanzania

Land Use Land Cover Change (LULCC) has a significant impact on water resources and ecosystems in sub-Saharan Africa (SSA). On the basis of three research projects we aim to describe and discuss the potential, uncertainties, synergies and science-policy interfaces of satellite-based integrated research for the Kilombero catchment, comprising one of the major agricultural utilized floodplains in Tanzania. LULCC was quantified at the floodplain and catchment scale analyzing Landsat 5 and Sentinel 2 satellite imagery applying different adapted classification methodologies. LULC maps at the catchment scale serve as spatial input for the distributed, process-based ecohydrological model SWAT (Soil Water Assessment Tool) simulating the changes in the spatial and temporal water balance in runoff components caused by LULCC. The results reveal that over the past 26 years LULCC has significantly altered the floodplain and already shows an impact on the ecosystem by degrading the existing wildlife corridors. On the catchment scale the anomalies of the water balance are still marginal, but with the expected structural changes of the catchment there is an urgent need to increase the public awareness and knowledge of decision makers regarding the effect of the relationship between LULCC, water resources and environmental degradation.

Building Entrepreneurial Ecosystems in Sub-Saharan Africa: A Stakeholder Perspective

Despite several economic difficulties that have been depicted in the popular press and in policy making circles, sub-Saharan Africa presents today undeniable business opportunities that have not been fully exploited. Several countries, such as Angola, Ghana, Kenya, and South Africa have seen their economies grow at faster rates than developed economies in the last decade. According to Chironga, Leke, Lund, and Van Wamelen (2011) and the McKinsey Global Institute (2010), Africans spent $860 billion on goods and services in 2008, more than the $835 billion that Indians spent, and more than the $821 billion of consumer expenditures in Russia. If the sub-Saharan Africa maintains its growth trajectory, consumers will spend $1.4 trillion worth of goods and services in 2020, which will be a little less than India’s projected $1.7 trillion but more than Russia’s $960 billion. As these economies progress, opportunities are opening in sectors, such as retailing, telecommunications, banking, infrastructure-related industries, resource-related businesses, healthcare, education, and the agricultural value chain (Chironga et al., 2011). To sustain this growth potential, Africa needs to develop strategies that foster homegrown entrepreneurs.

An Analysis of Ecosystem Vulnerability and Management Interventions in the Morogoro Region Landscapes, Tanzania

Ecosystems in sub-Saharan Africa are highly vulnerable to external perturbations. An in-depth understanding of the socio-ecological mechanisms is important for the effective management of vulnerable ecosystems. Using remotely sensed satellite imagery and social data from 335 households, the study examines how different ecological and socio-economic factors influence ecosystem vulnerability in Morogoro region, Tanzania. Remotely sensed data indicated negative patterns of change in ecosystem health both at the spatial and temporal scales. Multiple logistic regression analysis showed habitat fragmentation and forest burning as key threats (p=0.02). From a social point of view, low income level (54.6%) and limited knowledge of environmental conservation (18.5%) were considered major catalysts of ecosystem vulnerability. Statistical results showed livelihood diversification (45.1%), effective institutional frameworks (30.7%), and afforestation programmes (24.2%) to be key intervention measures. The methodology and policy implications of the study have a wider applicability in the long-term management of vulnerable landscapes.

Payments for Ecosystem Services as a Framework for Community‐Based Conservation in Northern Tanzania

Payments for ecosystem services (PES) are an increasingly promoted approach to conservation. These approaches seek to develop financial mechanisms that create economic incentives for the maintenance of ecosystems and associated biodiversity by rewarding those who are responsible for provision of ecological services. There are, however, few cases in which such schemes have been used as a strategy for conserving wildlife in developing countries and very few operational examples of such schemes of any sort in sub-Saharan Africa. In savannah ecosystems, large mammal populations generally depend on seasonal use of extensive areas and are widely declining as a result of habitat loss, overexploitation, and policies that limit local benefits from wildlife. Community-based conservation strategies seek to create local incentives for conserving wildlife, but often have limited impact as a result of persistent institutional barriers that limit local rights and economic benefits. In northern Tanzania, a consortium of tourism operators is attempting to address these challenges through an agreement with a village that possesses part of a key wildlife dispersal area outside Tarangire National Park. The operators pay the community to enforce voluntary restrictions on agricultural cultivation and permanent settlement in a defined area of land. The initiative represents a potentially cost-effective framework for community-based conservation in an ecologically important area and is helping to reconcile historically conflicting local and national interests relative to land tenure, pastoralist livelihoods, and conservation. Wider adaptation of payments for ecosystem services approaches to settings where sustaining wildlife populations depends on local stewardship may help address current challenges facing conservation outside state-protected areas in savannah ecosystems in sub-Saharan Africa and other parts of the world.