Climate change is a threat to food security. Wild-harvested food plants (WFPs) are important for the diets of millions of people and contribute to food security, especially in rural and low-income communities, but little is known about climate change risk to WFPs. Using species distribution models, we examined climate change risk to 1190 WFP species used by 19 native language groups in southern Africa. We project that 60% of species will experience an increase (40% a decrease) in range extent within southern Africa by 2060–2080 under a low warming scenario (Representative Concentration Pathway (RCP) 2.6), while range reductions for 66% of species are projected under a high warming scenario (RCP 8.5). Decreases in geographic range are projected for > 70% of WFP species traditionally used by some language groups. Loss of suitable climatic conditions is projected to decrease WFP species richness most in north-eastern southern Africa—with losses of > 200 species—while increases in species richness are projected in the south and east of South Africa. Availability of WFP species for food security during lean times is also projected to change. In south-eastern South Africa, local diversity of WFPs is projected to increase, while maize and sorghum yields decrease. However, this potential WFP nutritional safety net may be lost in central parts of the region, where declines in both crop yield and WFPs are projected. By looking beyond conventional crops to the exceptional diversity of WFPs, this research helps understanding linkages between WFPs, traditional knowledge, food security and climate change adaptation.

气候变化是对粮食安全的威胁。野生收获的食用植物（WFP）对于数百万人的饮食很重要，并有助于粮食安全，特别是在农村和低收入社区，但是人们对WFP的气候变化风险知之甚少。使用物种分布模型，我们研究了南部非洲19个土著语言群体使用的1190种世界粮食计划署物种的气候变化风险。我们预计，到2060-2080年，在低变暖情况下（代表浓度路径（RCP）2.6），非洲南部60％的物种范围将增加（减少40％），而66％的物种范围将减少预计在高温情况下（RCP 8.5）。预计某些语言群体传统上使用的世界粮食计划署物种中> 70％的地理范围将减少。预计适当气候条件的丧失将使南部非洲东北部的世界粮食计划署物种丰富度最大程度地下降（损失> 200种），而预计南非的南部和东部物种丰富度将增加。粮食计划署品种在贫瘠时期用于粮食安全的可及性也将发生变化。在南非东南部，粮食计划署的当地多样性预计将增加，而玉米和高粱的产量将下降。但是，这一潜在的世界粮食计划署营养安全网可能会在该地区中部地区丧失，预计该地区的作物单产和世界粮食计划署都将下降。通过将目光从传统作物转向粮食计划署的特殊多样性，这项研究有助于理解粮食计划署，传统知识，粮食安全和气候变化适应之间的联系。