Climate induced changes in benthic macrofauna–a non-linear model approach

Climate induced changes in benthic macrofauna–a non-linear model approach , This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Abstract The non-linear methods " optimally pruned extreme learning machine " (OPELM) and " optimally pruned k–nearest neighbours " (OPKNN) are applied to relate various climate indices to time series of biomass, abundance and species number of benthic macrofauna communities in the southern North Sea for the period 1978-2005. The results of these methods show that the performance in forecasting macrofauna communities is as poor as linear statistical downscaling if only one climate index is used as a predictor. If a multivariate predictor is used, OPKNN shows a good forecast for biomass and species number, but not for abundance. The improvement of the forecast is of major relevance especially in the presence of biological and climate regime shifts which occurred in the considered period. Highlights Two types of single layered neural networks (" optimally pruned extreme learning machine " and " optimally pruned k-nearest neighbours ") are used to forecast benthic macrofauna. Climate regime shift in 2001/2002 shifts the ecosystem of the southern North Sea to a new state regarding benthic macrofauna Benthic macrofauna biomass and species number is predictable for the period 1978-1999 using climate descriptors Benthic macrofauna variability cannot be forecasted after 2000 Combination of large scale and regional scale climate descriptors results in good hindcast of benthic macrofauna biomass and species number for the complete period 1978-2005 Benthic macrofauna abundance remains unpredictable