Ranking biodiversity risk factors using expert groups – Treating linguistic uncertainty and documenting epistemic uncertainty

Abstract

there is a high risk that management goals may not be achieved. This is the case at Toolibin 15 Lake, an internationally recognised wetland, where changed hydrology as a result of 16 agricultural development has detrimentally affected the quality and quantity of water entering 17 the lake. Although management actions have slowed or halted degradation of the lake's 18 biological assets, goals have not been fully achieved and management is under review. To rank 19 the hydrological risk factors threatening the lake's biota as a foundation for more detailed 20 planning, a structured elicitation process was used with an expert, cross-disciplinary group. 21Techniques used were explicitly aimed at minimising and documenting uncertainty. These 22 included calibration questions to assess the accuracy of experts, and tightly specified goals and 23 terms to minimise vagueness, ambiguity and redundancy. Surface water salinity, groundwater 24 salinity and drought were the only factors identified as having a high probability of causing 25 goal failure. Importantly, the majority of risk factors were evaluated as having a low probability 26 of causing goal failure, enabling these factors to be rapidly eliminated from short-term 27 consideration. The experts, acting anonymously when estimating probabilities, varied 28 considerably in the assessment of one risk. This underlines the importance of rigorous 29 processes to identify knowledge gaps and assess the likelihood that proposed management 30 will be successful. The elicitation process provided low cost, rapid assessment of large 31 numbers of risk factors with explicit assessment of uncertainty. 32 33

A practical guide to structured expert elicitation using the IDEA protocol

“…Encouragingly, the steps listed above are being readily adopted by conservation scientists to solve a range of problems. For example, the four‐step elicitation has been incorporated by Metcalf and Wallace (), Ban, Pressey, and Graham (), Chadés et al. (), Firn et al.…”

The contribution of nature to people: Applying concepts of values and properties to rate the management importance of natural elements

“…At the same time, it is acknowledged that individual people and groups will vary on how they relate element properties to values, as shown, for example, by the relationships between personal characteristics and preferences in landscape aesthetics (Howley et al, 2012;Kalivoda et al, 2014). Nevertheless, we considered there to be sufficient congruence between modelled and stakeholder representative outputs to apply the results in subsequent catchment planning processes, such as risk and feasibility assessment (e.g., Metcalf and Wallace, 2013;Smith et al, 2015b), and the selection of strategic management actions.…”

“…In particular, results can be influenced by framing and anchoring (Luchini and Watson, 2013), over-and under-confidence (Metcalf and Wallace, 2013;Speirs-Bridge et al, 2010), halo effects (Australian Centre for Excellence in Risk Analysis, 2010) and linguistic uncertainty (Burgman, 2005). A number of techniques were employed to manage these issues.…”

Managing natural resources for their human values

“…The abiotic filters were soil salinity, soil moisture, soil type, and site elevation. The selected filters relate to direct or near direct risk factors (Metcalf and Wallace 2013). For example, water quality and quantity are abiotic filters that present direct risks to the survival and reproduction of plants via mortality associated with salt toxicity or drought stress.…”