Planning complementary conservation of crop wild relative diversity in southern Africa

Abstract

Aim: To identify priority areas for in situ conservation and collection of germplasm for ex situ backup of crop wild relative (CWR) diversity in the Southern African Development Community (SADC) region as part of an action plan for the conservation and use of the region's important CWR diversity. Location: SADC region. Methods: Diversity, gap and climate change analyses at species and ecogeographic diversity levels were undertaken for 113 regional priority CWR taxa. Results: CWR hotspots were identified in Eswatini (former Swaziland), Malawi, Mozambique, South Africa, Tanzania and Zimbabwe. Twenty-one per cent of regionally priority CWR occur exclusively outside existing protected areas (PAs), 50% are not conserved ex situ, and 64% are predicted to be negatively impacted by climate change. A total of 120 existing PAs in 13 countries were identified as containing populations likely to persist in the future for 80% of CWR taxa and about 50% of the ecogeographic diversity of these taxa; remaining diversity can be conserved in an additional 151 complementary sites in 11 countries. Democratic Republic of the Congo, Madagascar, South Africa and Tanzania contain important areas for conserving CWR diversity in situ in which no negative climate change impact is predicted. Priority CWR diversity in the provinces of Bas-Congo (Democratic Republic of the Congo) and Cabinda (Angola) is threatened by climate change and should be collected urgently for ex situ conservation. Other areas rich in ecogeographic diversity that is not conserved ex situ are located in Angola, Democratic Republic of the Congo, Eswatini, Madagascar, Malawi, Mauritius, Mozambique, South Africa, Tanzania and Zimbabwe. Main conclusions: We identified 120 PAs and 151 complementary sites outside of PAs in 13 SADC countries that could form the basis of the SADC Network for In Situ Conservation of CWR. We also selected priority areas for filling gaps in ex situ collections and for field survey.