Drought‐tolerant succulent plants as an alternative crop under future global warming scenarios in sub‐Saharan Africa

Abstract

Globally, we are facing an emerging climate crisis, with impacts to be notably felt in semiarid regions across the world. Cultivation of drought‐adapted succulent plants has been suggested as a nature‐based solution that could: (i) reduce land degradation, (ii) increase agricultural diversification and provide both economic and environmentally sustainable income through derived bioproducts and bioenergy, (iii) help mitigate atmospheric CO2 emissions and (iv) increase soil sequestration of CO2. Identifying where succulents can grow and thrive is an important prerequisite for the advent of a sustainable alternative ‘bioeconomy’. Here, we first explore the viability of succulent cultivation in Africa under future climate projections to 2100 using species distribution modelling to identify climatic parameters of greatest importance and regions of environmental suitability. Minimum temperatures and temperature variability are shown to be key controls in defining the theoretical distribution of three succulent species explored, and under both current and future SSP5 8.5 projections, the conditions required for the growth of at least one of the species are met in most parts of sub‐Saharan Africa. These results are supplemented with an analysis of potentially available land for alternative succulent crop cultivation. In total, up to 1.5 billion ha could be considered ecophysiologically suitable and available for succulent cultivation due to projected declines in rangeland biomass and yields of traditional crops. These findings may serve to highlight new opportunities for farmers, governments and key stakeholders in the agriculture and energy sectors to invest in sustainable bioeconomic alternatives that deliver on environmental, social and economic goals.

Climate‐resilient crops: Lessons from xerophytes

“…All of them are C4 plants with adaptations for water-efficient carbon fixation and a prolific root system allowing efficient water absorption (Lovell et al, 2018;Valenc ßa et al, 2020); (ii) four trees -Populus euphratica, Populus deltoides, Populus trichocarpa and Salix purpurea that possess remarkable drought tolerance (K€ ohler et al, 2020;Monclus et al, 2006); (iii) two desert shrubs -Simmondsia chinensis (Wang et al, 2019) and Manihot esculenta (Muiruri et al, 2021) which possess great drought avoidance ability; and (4) two succulent species -Kalanchoe fedtschenkoi and Kalanchoe laxiflora. These plants belong to crassulacean acid metabolism type of photosynthesis and show high WUE, as well as an ability to grow on marginal or degraded land (Buckland et al, 2023). In summary, the strategies of our selected xerophytes encompass efficient carbon fixation capabilities, morphological and physiological adaptability and genotypic adaptation, among other diverse drought-tolerance mechanisms.…”

Biomass production of 14 accessions of cactus pear (Opuntia spp.) under semi‐arid land conditions

“…These adaptive traits are reflected in modelling simulations that show that O. ficus‐indica is expected to maintain climate‐resiliency in arid regions of the world while avoiding conflicts with traditional food production systems or contributing to deforestation (Owen et al., 2016; Yang et al., 2015). Lastly, O. ficus‐indica also exhibits growth stimulation in response to increasing atmospheric CO 2 concentrations (Cui et al., 1993; Cui & Nobel, 1994; Luo & Nobel, 1993; Nobel & Israel, 1994; North et al., 1995), suggesting that this and related cactus species might be useful for terrestrial CO 2 sequestration efforts and for a sustainable bioeconomy (Bautista‐Cruz et al., 2018; Buckland et al., 2023; Jardim et al., 2023).…”