This study investigated the temporal and spatial variation in photosynthetic activity of Vitellaria paradoxa (shea tree) growing in agroforestry parklands across two contrasting climatic zones of Burkina Faso. Measurements of chlorophyll fluorescence, chlorophyll content, leaf temperature, stomatal conductance, and environmental variables were conducted from April to December 2023 to assess physiological responses to climatic variability. Significant differences were observed between the northern and southern Sudanian phytogeographical zones, particularly in chlorophyll content, energy dissipation mechanisms, and photosynthetic performance. Trees in the more humid southern Sudanian zone exhibited higher chlorophyll content and better photosynthetic efficiency than those in the drier northern zone. Leaf temperature was strongly influenced by ambient temperature, while vapor pressure deficit and photosynthetically active radiation affected stomatal conductance and energy dissipation processes. The results demonstrate that V. paradoxa possesses physiological mechanisms that enable adaptation to changing environmental conditions, including regulation of heat dissipation, chlorophyll utilization, and gas exchange. These findings improve understanding of the ecophysiological resilience of shea trees under climate change and provide insights for sustaining agroforestry parklands in the Sudano-Sahelian region.
Tag: Agroforestry
Climate-growth relationships of Daniellia oliveri (Rolfe) Hutch. & Dalziel in the Sudanian zone of Mali, West Africa
Tree rings depend on seasonal variation in radial tree growth. Where they can be identified, their interannual variation may reflect climate variability. Compared to its use in temperate and boreal regions, tree-ring analysis has been less applied in tropical Africa, with weaker seasonality. Daniellia oliveri often forms the tallest trees in agroforestry parklands of the Sudanian savanna zone of Mali but its growth response to climate (rainfall, temperature) variability has not been documented. We analyzed six stem disks of D. oliveri and used standard dendrochronological methods to process the samples. Contrary to earlier literature likely based on more humid parts of the species distribution range, D. oliveri formed distinct growth ring boundaries in our study area. The mean annual radial growth was 2.73 ± 0.56 mm. All measured tree-ring series were successfully cross-dated with a GLK (Gleichläufigkeit) value of 76.3 ± 5.6. The final tree-ring chronology covers the period 1909-2021. After removing age-related growth trends, the tree-ring width index showed a significant relationship with records of annual rainfall (r2 = 0.46, n = 100 years, p < 0.001). The relationship between wet-season (June to September) precipitation and the residual chronology was slightly higher (r2 = 0.50, n = 100 years, p < 0.001). However, no significant correlation was found for temperature. These results imply that D. oliveri can be successfully used for dendrochronological studies with relevance for the management and restoration of the ecosystems in the Sudanian zone of West Africa, where long-term rainfall records are scarce.
Climate-growth relationships of Daniellia oliveri (Rolfe) Hutch. & Dalziel in the Sudanian zone of Mali, West Africa
Tree rings depend on seasonal variation in radial tree growth. Where they can be identified, their interannual variation may reflect climate variability. Compared to its use in temperate and boreal regions, tree-ring analysis has been less applied in tropical Africa, with weaker seasonality. Daniellia oliveri often forms the tallest trees in agroforestry parklands of the Sudanian savanna zone of Mali but its growth response to climate (rainfall, temperature) variability has not been documented. We analyzed six stem disks of D. oliveri and used standard dendrochronological methods to process the samples. Contrary to earlier literature likely based on more humid parts of the species distribution range, D. oliveri formed distinct growth ring boundaries in our study area. The mean annual radial growth was 2.73 ± 0.56 mm. All measured tree-ring series were successfully cross-dated with a GLK (Gleichläufigkeit) value of 76.3 ± 5.6. The final tree-ring chronology covers the period 1909-2021. After removing age-related growth trends, the tree-ring width index showed a significant relationship with records of annual rainfall (r2 = 0.46, n = 100 years, p < 0.001). The relationship between wet-season (June to September) precipitation and the residual chronology was slightly higher (r2 = 0.50, n = 100 years, p < 0.001). However, no significant correlation was found for temperature. These results imply that D. oliveri can be successfully used for dendrochronological studies with relevance for the management and restoration of the ecosystems in the Sudanian zone of West Africa, where long-term rainfall records are scarce.
Drivers of tree species diversity and aboveground carbon stocks in smallholder agroforestry systems in Laikipia East, Central Kenya
Agroforestry is highly valued for its role in carbon sequestration and biodiversity enhancement, yet empirical knowledge on how tree diversity and carbon stocks relate to environmental, farm-level, and household factors remain limited. This study combined whole-farm tree inventories and household surveys across 55 farms in Laikipia East Sub-County to assess patterns and drivers of woody species diversity and aboveground carbon stocks. A total of 108 woody species (6,756 individuals) across 38 families were recorded. Native species accounted for 56% of all species but only 40% of individuals, indicating dominance by a few exotic species. Species richness was highest in croplands (70 species) and boundary areas (59 species), which together accounted for 65% of all recorded trees. Young trees dominated the farms (>50%), mature trees made up about one-third, while large trees (<10%) were mostly confined to boundaries and croplands. Aboveground carbon stocks varied widely (mean: 16.5±7.1 t C/ha), with highest densities in woodlots (40.0±12.7 t C/ha) and homegardens (20.0±9.5 t C/ha). Multivariate analyses showed that plant density and average tree size were the strongest predictors of aboveground carbon (p< 0.01), while species richness was influenced primarily by the diversity of agroforestry practices and selected household characteristics, including respondent’s gender and household size (p < 0.05). Species diversity showed a weak relationship with aboveground carbon stocks (r < 0.20). These findings highlight both the ecological value and structural limitations of smallholder agroforestry. We recommend promoting tree conservation, native regeneration, and diversified agroforestry practices as strategies to enhance carbon storage and biodiversity outcomes in the region.
Agroeconomic performance and labor dynamics associated with coffee and black pepper diversified cropping systems
This study examines the agronomic, labor, and economic impacts of crop diversification in Robusta coffee and black pepper farming systems in Vietnam’s Central Highlands, where these commodities are major sources of income for approximately 800,000 households. In response to market volatility, many farmers have diversified production by integrating coffee, black pepper, and fruit or nut tree species within the same farms. Using survey data from 238 households, the study compares monoculture systems with diversified cropping systems to evaluate differences in resource use, productivity, labor requirements, and profitability. The results show that diversification enhances land-use efficiency through higher planting densities and improves nutrient-use efficiency while maintaining coffee and black pepper yields at the individual plant level. Although coffee and pepper yields per hectare tended to decrease in diversified systems, production from additional crops compensated for these reductions. Resource-use patterns differed between commodities, with black pepper systems requiring greater phosphorus inputs and pesticide use, whereas coffee systems relied more heavily on nitrogen fertilizers and irrigation. Diversified coffee systems applied water more frequently but in smaller amounts per tree, contributing to reduced overall water use. Labor requirements also varied considerably among systems. Black pepper production was the most labor-intensive activity, particularly during harvest periods. Diversification helped distribute labor demand more evenly throughout the year, reducing seasonal labor peaks. Economically, black pepper systems generated higher gross outputs but also incurred greater operating costs, resulting in gross margins similar to those of other systems. Diversified systems, however, provided higher returns to labor. Overall, the findings indicate that diversification offers important benefits in resource-use efficiency and labor management while maintaining comparable profitability under prevailing market conditions, supporting the development of more resilient farming systems in the Central Highlands.
Understanding gendered aspirations, decision-making, and fruit tree preferences in Makueni County, Kenya
In Makueni County, Kenya, smallholder farmers face erratic rainfall, severe droughts, recurrent floods, and water scarcity due to climate change. Understanding farmers’ aspirations is therefore essential to ensuring that support is relevant and responsive. This study explored: (1) farmers’ aspirations for farm composition, particularly fruit tree species, and potential changes in response to market and climate shifts; (2) gender dynamics shaping fruit tree cultivation decisions; and (3) connections between cultivated species, aspirations, and decision-making across gender and age. Data collected via focus group discussions, semi-structured interviews and key informant interviews revealed a shift towards fruit-tree-based livelihoods, ostensibly offering improved food and income security and reduced labour. However, this shift, dominated by a few exotic species, may reduce farm- and landscape-scale species diversity. Decision-making was strongly gendered: men dominated species selection and management and controlled large-scale sales of higher-value fruit, owing to land ownership, knowledge and cultural norms, while women held greater power over small-scale sales, lower-value species and the income these generated. To foster equitable, resilient farming systems, we recommend inclusive, gender-responsive fruit tree production and management training. Transforming gender relations to amplify women’s voices in species selection could diversify fruit tree portfolios and lead to more equitable and biodiverse farming systems.
Tree diversity and land use choices in agroforestry systems: co-learning through the FORCES game in Indonesia
Farmers make choices about their land-use portfolio based on their experience, incomplete information and social connections. Rather than imposing normative economic or ecological rationales for farmer choices, a participatory simulation game can lead to co-learning. We utilized a plot-level game, Farmer Options, Risks in Complex Ecological-Social system (FORCES), to explore the management of tree and crop diversity in three contrasting landscapes in Indonesia. We assessed farmer management choices, responses to socio-ecological pressures and quantified game impacts on changes in farmer discourse. We found gendered preferences for plant species and land-use practices. Most older farmers preferred tree-based system, while young farmers chose annual food crops, opting for higher income despite risks. Social, cultural, and ecological reasons played important role in decision-making alongside economic factors but depended on the local context. By clarifying consequences of farmers’ choices, a top-down and bottom-up approach can be reconciled in the search for sustainable landscape management.
Elucidating the reproductive systems and fruit description of the Breadnut (Brosimum alicastrum Sw., Moraceae), an underutilised opportunity food tree, in the Maya Biosphere Reserve, Guatemala
Brosimum alicastrum Sw. (Breadnut or Maya nut), of the Moraceae family, is an underutilised tropical food tree with high nutritional, cultural, and ecological importance in Mesoamerica. Despite its potential as a sustainable forest-based food crop, large uncertainty remains regarding its reproductive biology and fruit morphology, contributing to highly variable and unpredictable yields. This study elucidates the reproductive system, pollination strategy, and fruit characteristics of B. alicastrum in two forested areas of the Maya Biosphere Reserve, Guatemala: Uaxactún and Sierra del Lacandón. Using forest inventories, canopy-based floral observations, fruit and seedling assessments, and ethnobotanical interviews with local collectors, to assess site-specific variation in reproductive traits and yield proxies. Results demonstrate clear differences between populations. Uaxactún exhibited a predominantly monoecious system with female and hermaphroditic individuals, where nearly all trees showed signs of reproduction. In contrast, Sierra del Lacandón showed evidence of a dioecious population, with a substantial proportion of non-reproductive (male) trees, explaining lower and less reliable yields. Floral morphology, absence of animal pollinators, exposed stigmas, and abundant pollen strongly indicate wind pollination. Furthermore, the fruit is reclassified from a drupe or berry to a sorosis, a composite infructescence formed from the entire inflorescence. These findings reconcile longstanding contradictions in the literature and highlight the importance of population-specific reproductive strategies for management, conservation, and the future development of B. alicastrum as an opportunity tree crop for food security.
Common entry points and trade-offs for inclusive governance: balancing actor traits and policy in decision-making on forest restoration strategies
Forest and Landscape Restoration faces governance challenges due to social heterogeneity and a complex policy environment, creating a Gordian knot of contrasting needs and strategies. Scholars propose common entry points for inclusive governance and reconciling restoration strategies, but empirical evidence is scarce. The study addresses this gap by exploring common entry points from actor clusters and trade-offs for inclusive governance, and by identifying how actor traits and policy components are associated with FLR strategy decisions. It utilizes data from 269 actor interviews in Ethiopia, including actor categories, internal traits (deep core values, ecosystem service value, beliefs, and norms), restoration strategies, and the status of the policy environment. The analysis is based on the Agency-Structure framework using ordination and rank-ordered probit regression. Results reveal significant trade-offs between timber-pole production versus culture, NTFP versus soil vitality services, food versus microclimate services, biodiversity and water regulation versus carbon sequestration. Based on the preference scores, we identified five possible FLR groups: Nature-Norm Stewards (cluster 1), Food-security stewards (cluster 2), Market-driven utilitarians (cluster 3), Livelihood-oriented stewards (cluster 4), and sustainable timber and NTFP stewards (cluster 5). With possible entry points coming from Nature-Norm Stewards and Market-driven utilitarians. Reconciliation of assisted-natural-regeneration (ANR) strategies requires a focus on the bio-normative dimension, including biodiversity and cultural services, with coherent policies. Active strategies (plantations) necessitate the eco-timber dimension with policy clarity. Agroforestry requires a focus on the NTFP-oriented “soil-averse”, eco-timber, and biodiversity “eco-carbon” dimensions, along with coherent and inclusive policies. However, for sustainability and permanence, both nature-based and livelihood-based traits need to be considered simultaneously. Thus, calling for a more integrated landscape with numerous strategies. Actors perceive the policy environment as insufficient in clarity and inclusiveness, and as partly incoherent. Policy clarity and inclusiveness limit ANR decisions, whereas coherence limits decisions on active strategies. Thus, successfully implementing national and international FLR targets and ensuring sustainability requires establishing policy instruments to bridge the contrasting value-beliefs among actors. Our theory-based framework for identifying common practical entry points for inclusive governance and decision-making for FLR strategy has proven applicable and is recommended for further use.
Testing the ecological apparency hypothesis in Sudano-Sahelian parklands in Burkina Faso
This study investigates the relationship between the ecological apparency of woody plant species and their local importance to farming households in agroforestry parklands of West Africa. Agroforestry systems, which integrate trees with agricultural production, are increasingly recognized as nature-based solutions that enhance climate resilience and food security. Through ethnobotanical surveys with 150 farmers and vegetation inventories conducted in their parklands, the study assessed local plant importance using the Use Value (UV) index and ecological apparency using the Importance Value Index (IVI). Results identified Vitellaria paradoxa, Lannea microcarpa, and Parkia biglobosa as the most frequently used species, while Vitellaria paradoxa, Azadirachta indica, and Adansonia digitata were the most ecologically dominant and apparent. Statistical analyses revealed positive relationships between ecological apparency and local importance, providing support for the Ecological Apparency Hypothesis. Strong evidence was found that more apparent species were more important for energy production, construction, medicinal uses, soil fertility management, income generation, and food provision. The findings demonstrate that the most abundant and visible woody species in agroforestry parklands tend to be those most valued by local communities, highlighting their critical role in sustaining rural livelihoods, ecosystem services, and climate-resilient agricultural systems.