Influence of land-derived stressors and environmental variability on compositional turnover and diversity of estuarine benthic communities

It can be challenging to differentiate community changes caused by human activities from the influence of natural background variability. Using gradient forest analysis, we explored relative importance environmental factors, operating across multiple spatio-temporal scales, in influencing patterns compositional turnover estuarine benthic macroinvertebrate communities New Zealand. Both land-derived stressors (represented sediment mud content and total nitrogen phosphorus content) variables sea surface temperature, Southern Oscillation Index, wind-wave exposure) were important predictors turnover, reflecting a matrix processes interacting space time. Generalized linear models used determine whether measures diversity, which are commonly as indicators ecological health on local scale, changed way that was consistent with along gradient. As expected, stressor gradients negatively associated diversity indices, suggesting decline increase. This study moves towards an ecosystem-based management approach focusses cumulative effects rather than single considering how health, against variability several scales.