A condition metric for Eucalyptus woodland derived from expert evaluations

Abstract

The evaluation of ecosystem quality is important for land-management and land-use planning.Evaluation is unavoidably subjective, and robust metrics must be based on consensus and the structured use of observations. We devised a transparent and repeatable process for building and testing ecosystem metrics based on expert data. We gathered quantitative evaluation data on the quality of hypothetical grassy woodland sites from experts. We used these data to train a model (

Expert predictions of changes in vegetation condition reveal perceived risks in biodiversity offsetting

“…Despite reasonable concerns about the trading among attributes in aggregate scores of biodiversity value or vegetation condition [14], aggregate values are often the metric used to compare gains and losses within biodiversity offsetting. While concepts such as vegetation condition are inherently subjective [29] previous research has demonstrated that experts can generate consistent and reliable aggregate scores that represent biodiversity value and habitat quality [29, 30]. In this paper we consider both individual attributes and an expert generated aggregate index of vegetation condition.…”

“…Firstly, we captured expert point predictions about the current and future aggregate condition of a vegetation patch. This approach has been shown to usefully capture complex belief models of existing habitat value [29, 30], though the method has not yet been extended to future predictions. This elicitation exercise was completed by all 29 experts.…”

“…Our approach followed that of Sinclair and colleagues [29, 30] in that experts were asked to rank and score synthetic WSGW vegetation patches (‘sites’), based on their current and future contributions to persistence of biodiversity, assuming this could be captured by a single aggregate value representing vegetation condition. Unlike Sinclair et al [29, 30] our primary aim was not to generate a metric for predicting vegetation condition but rather to explore expert opinion about change in the aggregate value over time. We sought to examine whether experts generated consistent current and future estimates for comparable sites and identify those covariates correlated with their predicted changes.…”

“…Experts were not aware that their set included five common sites. These five sites were included to ensure that all experts were considering sites across the full spectrum of variation in the ecosystem, as a means of calibrating their judgements [29, 30].…”

Quantifying uncertainty in the identification of endangered ecological communities

“…A desktop structured expert elicitation, with both real and artificial samples, was undertaken within a workshop setting (e.g., Sinclair, Bruce, Griffioen, Dodd, & White, 2018) because it enabled us to: (a) control for variation in species detectability, both among observers and arising from seasonal variation; (b) maximise the range of ecological communities assessed; and (c) reduce cost and logistics. Although experts are often required to undertake assessments in the field, experts also allocate archival plot records to types and review and revise prior allocations based on sample data alone.…”