Climatic suitability predictions for the cultivation of macadamia and walnuts in existing land-use zones and forest management regimes under climate change scenarios: addressing food security in the mid-hills of Nepal

Abstract

The consequences of climate change threaten existing agriculture systems across Nepal. Projected climate changes will impact agriculture diversity, leading to an increased food insecurity. Hilly areas are populated by smallholder farmers, who have practised subsistence agriculture and forestry for centuries. There is enormous potential for communities to produce food in agricultural or forest lands that are degraded or sparsely covered by trees. However, little is known about the impact of climate change and the suitability of these areas for crops. This study explores the possibility of developing the cultivation of two high-nutrition nuts, macadamia and walnut, according to the current distribution of land-use zones, forest management regimes and types. We mapped climatic suitability for both species at present and in the future. We show that the ‘optimal’ range for macadamia growth will increase while the ‘optimal’ range for walnuts will decrease. The most favourable change will be in forest, agriculture and shrub zones. We recommend planting macadamia nut trees as an intercrop in agricultural fields and adapting the forestry policy so that it allows planting suitable tree crops in degraded forests in order to mitigate the consequences of climate change and to improve the living conditions of forest communities.