Estimating in situ conservation costs of Zambian crop wild relatives under alternative conservation goals

Crop wild relatives (CWR) are a globally threatened group of plants, harbouring valuable genes that are sometimes used to enhance commercial crop varieties and landraces. A lack of recognition in national planning for biodiversity conservation has resulted in inadequate CWR conservation strategies, particularly in situ. There is little information on in situ conservation costs, and this paper uses a payment for agrobiodiversity conservation services (PACS) approach to estimate the in situ costs of conserving CWR in Zambia, where 30 CWR have been prioritised for conservation (of which nine are present in our sample). Competitive tender bid offers were elicited from farmers willing to accept compensation for providing a CWR conservation service. Using data from 26 communities we determined the on-farm cost of conserving CWR, specifically in field margins/borders. Heterogeneity was evident in farmer bid offers, suggesting discriminatory price mechanisms can potentially deliver cost savings over uniform payment rules. Selection of bid offers under four different conservation goals using a binary linear programming (BLP) model reveals conservation costs ranging from US$ 23 to 91/ha per year. An untargeted area goal provided a least-cost procurement of conservation services ($ 2.3 k per year), followed by a targeted area goal ($ 5.9 k per year). The cost of selecting conservation sites increased when other constraints were added to the BLP model, including those concerning social equity ($ 6.4 k per year), and diversity ($ 9.2 k per year) goals. Overall, the findings suggest the use of competitive tenders, coupled with CWR data and BLP modelling, can potentially add much to improve the efficiency of in situ CWR conservation.