Abstract
The objective of the proposed research is to experimentally explore if drastic regime shifts due to alternative stable states and positive feedback mechanisms are important structuring factors in benthic ecosystems. Rather than occurring gradually, newly developed theory and recent modeling results suggest that changes in benthic ecosystems may occur in sharp transition steps in response to gradual changes in organic carbon loading. Thus, the effects of increased organic carbon loading on microbial abundance, microbial degradation pathways and benthic community structure will be explored experimentally. In controlled benthic mesocosms the partitioning between oxic, suboxic and anaerobic degradation pathways as well as the influence of benthic macrofauna will be studied to obtain an integrated view of the ecosystem functioning and its response to organic carbon loading. The experimental research will be conducted and developed in close interaction with diagenetic model development, and address some of the main gaps that exist between simple models and complex reality. The existence of alternative stable states could potentially have formidable consequences for the conservation and management of benthic ecosystems, and our understanding of their response to changing organic carbon loadings (e.g. due to eutrofication or global change) is imperative.
Netherlands