52 The benefits of biodiversity can be difficult to measure, define and value. However, if these benefits are disregarded or given a low priority in appraisal work, there is a risk of excessive and potentially irreversible degradation of natural resource stocks.
53 Defra and the Forestry Commission fund research on the valuation of biodiversity that is concerned both with developing methodological approaches and deriving empirical estimates.30
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30 Guidance is also available from two OECD publications, "Handbook of biodiversity valuation: a guide for policy makers" and "Valuation of Biodiversity Benefits: Selected Studies."