Ecosystem states: Creating a data-derived, ecosystem-scale ecological response model that is explicit in space and time

摘要: Abstract Increasing difficulties associated with balancing consumptive demands for water and achieving ecological benefits in aquatic ecosystems provide opportunities new ecosystem-scale response models to assist managers. Using an Australian estuary as a case study, we developed novel approach create data-derived state-and-transition model. The model identifies suites of co-occurring birds, fish, benthic invertebrates macrophytes (as ‘states’) the changing physico-chemical conditions that are each (‘transitions’). first used cluster analysis identify sets biota. Differences data state were identified using classification trees, biotic distinctness resultant statistical tested similarities. predictive capacity was cases. Two created different time-steps (annual quarterly) then combined capture both longer-term trends more-recent declines condition. We eight ecosystem states differentiated by mix water-quantity water-quality variables. Each represented distinct assemblage under well-defined conditions. ‘basins attraction’ identified, four tidally-influenced states, another independent tidal influence. Within basin, described continuum relative health, manifest through declining taxonomic diversity abundances. main threshold determining health whether freshwater flows had occurred region during previous 339 days. Canonical analyses principal coordinates demonstrated variance environmental set well captured (87%) 52% biological also captured. latter increased >80% when long- short-term analysed separately, indicating available Coorong well. This thus data-derived, multivariate model, where neither nor transitions determined priori. did not over-fit data, robust patchy or missing choice initial clustering technique random errors set, well-received local natural resource However, causal relationships requires additional testing, particularly future episodes recovery. shows significant promise simplifying management definitions condition and, via scenario analyses, can be manager decision-making large, complex future.