Climate suitability predictions for the cultivation of macadamia (Macadamia integrifolia) in Malawi using climate change scenarios

several issues should be considered in interpreting and applying the results. Though we identi- fied areas as suitable for macadamia production based on environmental predictors, however on the ground, this may not directly translate to the size of the arable land. In addition, other physical (soil physical and chemical factors) and socio-economic factors (including the gender and age of the smallholder farmers, availability of agricultural advisory services, access to roads, and market availability) which are used in determining the suitability of an area for crop production were not considered in our analysis. It is therefore recommended to take extra caution when using the results of this study. Nonetheless, the results of this analysis are important for future planning purposes. Therefore, there is a need for a thorough evaluation of adaptation approaches suggested for smallholder macadamia farmers, as these may be dif- ferent from those utilized by commercial growers. 5. Conclusions An ensemble model was used in this study to determine Malawi’s current and future suitability for macadamia production. The study’s findings lead to three important conclusions. For start- ers, precipitation is the most important determinant of macadamia suitability in Malawi. Sec- ond, the current and future macadamia production areas identified exist on agricultural land currently used to grow other crops. As a result, we propose promoting macadamia intercrops and agroforestry as a climate change adaptation strategy. Third, the extent of suitable areas for

macadamia production in Malawi is projected to decrease under both emission scenarios uti- lized in this analysis, and the most vulnerable areas are those in southern Malawi. Thus, we conclude that the macadamia sector faces production risks from climate change, but there are opportunities for adaptation strategies to build a resilient sector in Malawi. Supporting information S1 Fig. Map showing the districts of Malawi. (TIF) S1 Table. Suitable climatic conditions for macadamia production in Malawi. (DOCX) S2 Table. Regions and districts in Malawi. (DOCX) S3 Table. Bioclimatic variables available in WorldClim. (DOCX) S4 Table. The general circulation models (GCMs) used to obtain climatic variables under scenarios RCP 4.5 and RCP 8.5 in 2050. (DOCX) S5 Table. Characteristics of climate change scenarios by the 2050s (RCPs). (DOCX) S6 Table. Future distribution area of macadamia production in Malawi by 2050. (DOCX) S7 Table. Areas that will remain suitable for macadamia production by the 2050s by region. (DOCX) PLOS ONE Macadamia integrifolia: Climate suitability of Malawi PLOS ONE | https://doi.org/10.1371/journal.pone.0257007 September 9, 2021 16 / 20