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The rapid expansion of agrifood exports from low‐ and middle‐income countries and the contribution of global value chains to rural development are well‐documented in the literature. Also, studies on modernization of domestic food value chains in these countries are emerging. Yet, the linkages between global and local value chains are rarely studied. On the one hand, the development and expansion of global value chains may create competition with local value chains for land, labor, water, soil nutrients, and other resources. On the other hand, positive spillover effects, such as investment, technical or institutional spillovers, may occur and spur the development of local value chains. In this article, we put forward a conceptual discussion on the type of linkages between global and local value chains, and how these depend on crop and value chain characteristics. We review the empirical evidence on these linkages. Our focus is on Africa, where agrifood exports and global value chains evolved rapidly and where challenges remain to upgrade and increase efficiency in local food value chains. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 pandemic is of grave concern. As scientific data is being collected about the nature of COVID-19, government leaders and policy makers are challenged. They might feel pressured to take strong measures to stop virus spread. However, decisions could cause more harm than do good. This study maps all existing literature regarding the impact of COVID-19 containment measures on the health and healthcare of children in East-Africa., Methods: This scoping review follows Population Concept Context guidelines of Arksey and O'Malley and PRISMA 2020 checklist. PubMed, Web of Science, and Embase were searched. All peer-reviewed literature published in English between January 2020 and October 2022 was considered. Initial screening of titles and abstracts was undertaken independently by two reviewers, with a third available in case of doubt. This was followed by full-text screening involving two independent reviewers., Results: In total, 70 studies were included. Eight containment measures affecting children's health and healthcare were distinguished: lockdowns, school closures, physical distancing, travel restrictions, business closures, stay-at-home orders, curfews, quarantine measures with contact tracing. The consensus in the studies is that containment measures could minimise COVID-19 spread but have adverse indirect effects on children in East-Africa. Seven indirect effects were distinguished: economic damage, limited education access, food insecurity, child abuse, limited healthcare access, disrupted health-programs, and mental health challenges., Conclusion: Government leaders and policy makers should take adverse indirect effects of COVID-19 measures into account, particularly in resource-limited regions such as East-Africa, apply a holistic approach, and strengthen socioeconomic and health-systems to protect the most vulnerable., (© 2023 The Authors. The International Journal of Health Planning and Management published by John Wiley & Sons Ltd.)

Large herbivorous mammals play an important role in structuring African savannahs and are undergoing widespread population declines and local extinctions, with the largest species being the most vulnerable. The impact of these declines on key ecological processes hinges on the degree of functional redundancy within large-herbivore assemblages, a subject that has received little study. We experimentally quantified the effects of three browser species (elephant, impala and dik-dik) on individual- and population-level attributes of Solanum campylacanthum (Solanum incanum sensu lato), an encroaching woody shrub, using semi-permeable exclosures that selectively removed different-sized herbivores. After nearly 5 years, shrub abundance was lowest where all browser species were present and increased with each successive species deletion. Different browsers ate the same plant species in different ways, thereby exerting distinct suites of direct and indirect effects on plant performance and density. Not all of these effects were negative: elephants and impala also dispersed viable seeds and indirectly reduced seed predation by rodents and insects. We integrated these diffuse positive effects with the direct negative effects of folivory using a simple population model, which reinforced the conclusion that different browsers have complementary net effects on plant populations, and further suggested that under some conditions, these net effects may even differ in direction. [ABSTRACT FROM AUTHOR]

Large native mammals are declining dramatically in abundance across Africa, with strong impacts on both plant and animal community dynamics. However, the net effects of this large-scale loss in megafauna are poorly understood because responses by several ecologically important groups have not been assessed. We used a large-scale, replicated exclusion experiment in Kenya to investigate the impacts of different guilds of native and domestic large herbivores on the diversity and abundance of birds over a 2-year period. The exclusion of large herbivorous native mammals, including zebras ( Equus burchelli), giraffes ( Giraffa camelopardalis), elephants ( Loxodonta africana), and buffalos ( Syncerus caffer), increased the diversity of birds by 30%. Most of this effect was attributable to the absence of elephants and giraffes; these megaherbivores reduced both the canopy area of subdominant woody vegetation and the biomass of ground-dwelling arthropods, and both of these factors were good predictors of the diversity of birds. The canopy area of subdominant trees was positively correlated with the diversity of granivorous birds. The biomass of ground-dwelling arthropods was positively correlated with the diversity of insectivorous birds. Our results suggest that most native large herbivores are compatible with an abundant and diverse bird fauna, as are cattle if they are at a relatively low stocking rate. Future research should focus on determining the spatial arrangements and densities of megaherbivores that will optimize both megaherbivore abundance and bird diversity. [ABSTRACT FROM AUTHOR]

Many large mammal species are declining in African savannas, yet we understand relatively little about how these declines influence other species. Previous studies have shown that the removal of large herbivorous mammals from large-scale, replicated experimental plots results in a dramatic increase in the density of small mammals, an increase that has been attributed to the relaxation of competition between rodents and large herbivores for food resources. To assess whether the removal of large herbivores also influenced a predator of small mammals, we measured the abundance of the locally common olive hissing snake, Psammophis mossambicus, over a 19-mo period in plots with and without large herbivores. Psammophis mossambicus was significantly more abundant in plots where large herbivores were removed and rodent numbers were high. Based on results from raptor surveys and measurements of vegetative cover, differences in snake density do not appear to be driven by differences in rates of predation on snakes Instead, snakes appear to be responding numerically to greater abundances of small-mammal prey in areas from which large herbivores have been excluded. This is the first empirical demonstration of the indirect effects of large herbivores on snake abundance and presents an interesting example of how the influence of dominant and keystone species can move through a food web. [ABSTRACT FROM AUTHOR]

Pollination by animals is a key ecosystem service 1 , 2 and interactions between plants and their pollinators are a model system for studying ecological networks, 3 , 4 yet plant-pollinator networks are typically studied in isolation from the broader ecosystems in which they are embedded. The plants visited by pollinators also interact with other consumer guilds that eat stems, leaves, fruits, or seeds. One such guild, large mammalian herbivores, are well-known ecosystem engineers 5-7 and may have substantial impacts on plant-pollinator networks. Although moderate herbivory can sometimes promote plant diversity, 8 potentially benefiting pollinators, large herbivores might alternatively reduce resource availability for pollinators by consuming flowers, 9 reducing plant density, 10 and promoting somatic regrowth over reproduction. 11 The direction and magnitude of such effects may hinge on abiotic context-in particular, rainfall, which modulates the effects of ungulates on vegetation. 12 Using a long-term, large-scale experiment replicated across a rainfall gradient in central Kenya, we show that a diverse assemblage of native large herbivores, ranging from 5-kg antelopes to 4,000-kg African elephants, limited resource availability for pollinators by reducing flower abundance and diversity; this in turn resulted in fewer pollinator visits and lower pollinator diversity. Exclusion of large herbivores increased floral-resource abundance and pollinator-assemblage diversity, rendering plant-pollinator networks larger, more functionally redundant, and less vulnerable to pollinator extinction. Our results show that species extrinsic to plant-pollinator interactions can indirectly and strongly alter network structure. Forecasting the effects of environmental change on pollination services and interaction webs more broadly will require accounting for the effects of extrinsic keystone species., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)