Combining community needs and preferences with dryland plant expertise in order to select suitable native species for large‐scale natural capital restoration is the approach that has been successful in the Sahel as part of Africa's Great Green Wall program. In order to increase plant diversity and restore degraded land, we investigated four cross‐border regions of Mali, Burkina Faso, and Niger, all located in dryland ecosystems of the Sahel. In 120 beneficiary village communities, with a total population of over 50,000 farmers, including 51% women, participatory diagnostic meetings were conducted, leading to the selection of 193 plant species, most of which were mainly used for food, medicine, fodder, and fuel. Of these, 170 were native and considered suitable for enriching and restoring those village lands. The most environmentally well‐adapted and economically relevant species were prioritized, quality seeds were collected, and nursery seedlings produced under technical supervision of villages. From 2013 to 2015, 55 woody and herbaceous species were planted to initiate restoration of 2,235 ha of degraded land. On average, 60% of seedlings survived and grew well in the field after three rainy seasons. Due to its multiple uses, including gum arabic production, Acacia senegal was preferred by local people in most cases, accounting for 30% of seedlings planted. Such promising results, in an effort to restore degraded land for and with the help of thousands of farmers, could not have been achieved without the combination of scientific plant expertise and efficient rural capacity development, underpinned by high levels of community engagement.

Neem (Azadirachta indica) seed is reputed to have limited tolerance to desiccation, to be sensitive to chilling and imbibitional stress, and to display intermediate storage behaviour. To understand this behaviour the properties of water in seed tissues were studied. Water sorption isotherms showed that at similar relative humidity (RH), the water content was consistently higher in axes than in cotyledons, mainly due to the elevated lipid content (51%) in the cotyledons. Using differential scanning calorimetry, melting transitions of water were observed at water contents higher than 0.14 g H2O g-1 DW in the cotyledons and 0.23 g H2O g-1 DW in the axes. Beside melting transitions of lipid, as verified by infrared spectroscopy, changes in heat capacity were observed which shifted with water content, indicative of glass-to-liquid transitions. State diagrams are given on the basis of the water content of seed tissues, and also on the basis of the RH at 20 degrees C. Longevity was considerably improved, and the sensitivity to chilling/subzero temperatures was reduced when axis and cotyledons were dehydrated to moisture contents < or = of approximately 0.05 g H2O g-1 DW. However, longevity during storage at very low water contents was limited. A possible mechanism for the loss of sensitivity to chilling/subzero temperatures at low water contents is discussed. The results suggest that dry neem seeds in the glassy state have great potential for extended storability, also at subzero temperatures.

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Storage of neem (Azadirachta indica) seeds is difficult because of their sensitivity to chilling stress at moisture contents (MC) > or =10% or imbibitional stress below 10% MC. The hypothesis was tested that an elevated gel-to-liquid crystalline phase transition temperature (Tm) of membranes is responsible for this storage behaviour. To this end a spin probe technique, Fourier transform infrared microspectroscopy, and electron microscopy were used. The in situ Tm of hydrated membranes was between 10 degrees C and 15 degrees C, coinciding with the critical minimum temperature for germination. During storage, viability of fresh embryos was lost within two weeks at 5 degrees C, but remained high at 25 degrees C. The loss of viability coincided with an increased leakage of K+ from the embryos upon imbibition and with an increased proportion of cells with injured plasma membranes. Freeze-fracture replicas of plasma membranes from chilled, hydrated axes showed lateral phase separation and signs of the inverted hexagonal phase. Dehydrated embryos were sensitive to soaking in water, particularly at low temperatures, but fresh embryos were not. After soaking dry embryos at 5 degrees C (4 h) plus 1 d of further incubation at 25 degrees C, the axis cells were structurally disorganized and did not become turgid. In contrast, cells had a healthy appearance and were turgid after soaking at 35 degrees C. Imbibitional stress was associated with the loss of plasma membrane integrity in a limited number of cells, which expanded during further incubation of the embryos at 25 degrees C. It is suggested that the injuries brought about by storage or imbibition at sub-optimal temperatures in tropical seeds whose membranes have a high intrinsic Tm (10-15 degrees C), are caused by gel phase formation.