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The Anthropocene has brought with it many challenges, the primary of which are climate change and food security. The growing global population increasingly demands more from a shrinking resource base, while variable climate conditions make future provision uncertain. To address issues of low agricultural productivity and land degradation, conservation agriculture (CA) has been promoted in smallholder settings across Africa. CA is an agricultural package that consists of three key principles (minimum soil disturbance, mulching, and crop rotation) and its success depends on the simultaneous implementation of all three principles. However, CA has met with limited success. A scoping review was conducted to assess the barriers and enablers of CA for smallholder farmers in the Southern African Development Community (SADC) – a regional inter-governmental economic community. The scoping review included peer-reviewed articles, book chapters, reviews, and grey literature written in English that focused on the contextual links between CA adoption and the smallholder context, since 2015. Six electronic databases were consulted, and included records were charted according to a pre-defined data extraction form. A total of 66 records were included. A qualitative content analysis was performed. The findings indicated four central themes – physical resources, human resources, informational resources, and financial resources. The four central themes and their respective categories, detailing barriers and enablers, were combined to produce the Conservation Agriculture Suitability Framework for Smallholder Farmers. The review contributes to the knowledge base of the CA discipline and practice by revealing the contextual determinants of successful CA implementation. Ultimately, the success of CA in southern Africa will be underpinned by how well it fits into the broader smallholder farming system. • Climate variability and population growth in Africa has created vulnerability in the smallholder farming sector as well as food security challenges. • Conservation agriculture (CA) has been promoted to address these challenges but has seen low adoption rates and high disadoption rates. • A scoping review was conducted to assess the barriers and enablers of CA for smallholder farmers in southern Africa • Barriers and enablers are context specific, not universal, and are not unique to CA but are rather general constraints of smallholder livelihoods. • The CA Suitability Framework for Smallholder Farmers created to facilitate appreciation of the heterogenous smallholder context and promote incremental change through flexible and participatory approaches that accommodate local barriers and enablers. [ABSTRACT FROM AUTHOR]

• South Africa successfully developed land degradation neutrality targets. • Biomes rather than land cover types form the fundamental unit of analysis. • Subjectively and objectively developed bassline data was combined for identifying priority interventions. • The global indicators proved problematic for identifying interventions. • Alien plant invasions and woody plant densification were the most pressing degradation problems needing intervention. South Africa undertook a national Land Degradation Neutrality (LDN) target setting process during 2017/18 in response to the United Nations Convention to Combatting Desertification's call for signatory countries to voluntarily commit to LDN as also requested under Sustainability Development Goal 15.3. The process was supported by the Global Mechanism (GM) and followed their guidelines. This resulted in an ambitious set of targets being set for 2030. Early in the process it was recognised that biome level or landscape process based (bush encroachment, alien plant species removal) targets were more appropriate than location specific targets. South Africa has used the World Overview of Conservation Technologies and Approaches (WOCAT) Mapping Questionnaire (QM), to conducted two, ten years apart, assessments based on experts' perception of municipal level land degradation. The spatial location and extent of degradation, as identified from these studies, differed substantially from the three global indicators suggested as a baseline for LDN target setting. An analysis of the reasons for the discrepancies between the UNCCD indicators from the perception-based studies, and the implications this has for setting and monitoring South African land degradation is the main focus of this paper. [ABSTRACT FROM AUTHOR]

The West African savanna experiences a prolonged dry season with Harmattan winds which facilitate large and persistent biomass burning from November to April. The fires are mostly caused by humans, mainly in pursuit of the day to day livelihood activities. We examined how fire influences the population structure and abundance of two economically important woody species Vitellaria paradoxa (Shea tree) and Anogeissus leiocarpa (African Birch) in six land use types in the Guinea savanna, Ghana. We calculated the stand basal area, mean densities of juveniles and adult trees, Lorey's mean height of adult trees and Simpson's index of dominance. Eight diameter size classes of each species were analysed by comparing their observed distributions to a three-parameter Weibull distribution across the land use types. A total of 3366 individuals of A. leiocarpa (n = 1,846) and V. paradoxa (n = 1,520) were enumerated. The basal area of A. leiocarpa and V. paradoxa in sacred groves (16.9 m2 ha−1) and unburnt woodlands (20.6 m2 ha−1) was higher than the estimates in the other land use types. High mean densities of A. leiocarpa and V. paradoxa were found in sacred groves (22.7 ± 29.7 stems ha−1) and fallows (15.3 ± 2.2 stems ha−1), respectively. Mean density of juveniles of both A. leiocarpa (248.0 ± 89.1 stems ha−1) and V. paradoxa (68.0 ± 29.7 stems ha−1) were higher in unburnt woodlands than in the other land use types. A. leiocarpa was absent in fallows and burnt crop fields. An inverse J-shaped distribution was found in sacred groves for both species. The absence of A. leiocarpa in burnt crop fields and the decrease of some size classes of V. paradoxa in both burnt and unburnt crop fields indicate the need for sustainable conservation of both species. Furthermore, the inverse J-shape distribution found in sacred groves for both A. leiocarpa and V. paradoxa implies that these species thrive best with minimal anthropogenic disturbances. Although species conservation is achieved through conventional protection, traditional or cultural conservation practices which avoid the indiscriminate use of fire should be highly promoted to ensure sustainable conservation of species. • We examined how fire influences the population structure and abundance of two important woody species in a West African parkland. • High mean densities of A. leiocarpa and V. paradoxa were found in some land use types. • An inverse J-shaped distribution was found in community conserved groves for both species. • Decrease in size classes of V. paradoxa in some land use types are an indication of the need for conservation of species. [ABSTRACT FROM AUTHOR]

Abstract: There is widespread harvesting of the leaves of Aloe ferox to supply bitters and gel for cosmetic and health products. Government and private agencies are interested in expanding the industry as a means of providing income for poor rural communities. With the growing interest in the commercial use of A. ferox it is important that harvesting programmes are based on an adequate understanding of the ecology and productivity of the species, which will underpin estimates of possible sustainable yields. In this paper we report mean annual growth rates of 283 A. ferox plants (at six sites) during the 2005/2006 season. Growth was variable across sites and plant height. In terms of sites, the mean height growth ranged between 1.7 cm per plant per year at site 4 and 4.6 cm at site 2. The mean height increment across all sites and plants was 2.8±0.2 cm. Plant height had a strong effect on annual increment with small plants (<6 cm) more than doubling their height in the 12 month period, whereas plants taller than 2 m grew by approximately 1% over the year. Across the five unburnt sites, the mean standing stock of leaves grew by two per plant. The proportion of plants flowering increased progressively with plant height. Most (90%) of the plants that flowered in 2005 did so again in 2006. [Copyright &y& Elsevier]