title: The role of recurrent disturbances for ecosystem multifunctionality.
abstract: Ecosystem functioning is threatened by an increasing number of anthropogenic stressors, creating a legacy of disturbance that undermines ecosystem resilience. However, few empirical studies have assessed to what extent an ecosystem can tolerate repeated disturbances and sustain its multiple functions. By inducing increasingly recurring hypoxic disturbances to a sedimentary ecosystem, we show that the majority of individual ecosystem functions experience gradual degradation patterns in response to repetitive pulse disturbances. The degradation in overall ecosystem functioning was, however, evident at an earlier stage than for single ecosystem functions and was induced after a short pulse of hypoxia (i.e., three days), which likely reduced ecosystem resistance to further hypoxic perturbations. The increasing number of repeated pulse disturbances gradually moved the system closer to a press response. In addition to the disturbance regime, the changes in benthic trait composition as well as habitat heterogeneity were important for explaining the variability in overall ecosystem functioning. Our results suggest that disturbance-induced responses across multiple ecosystem functions can serve as a warning signal for losses of the adaptive capacity of an ecosystem, and might at an early stage provide information to managers and policy makers when remediation efforts should be initiated.
authors.affiliation: Tvärminne Zoological Station, University of Helsinki, J.A. Palméns väg 260, FI-10900 Hanko, Finland. anna.villnas@environment.fi
authors.forename: Anna
authors.initials: A
authors.lastname: Villnäs
authors.affiliation: Tvärminne Zoological Station, University of Helsinki, J.A. Palméns väg 260, FI-10900 Hanko, Finland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Norkko
authors.affiliation: Tvärminne Zoological Station, University of Helsinki, J.A. Palméns väg 260, FI-10900 Hanko, Finland.
authors.forename: Susanna
authors.initials: S
authors.lastname: Hietanen
authors.affiliation: Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark.
authors.forename: Alf B
authors.initials: AB
authors.lastname: Josefson
authors.affiliation: Marine Research Centre, Finnish Environment Institute, P.O. Box 140, FI-00251 Helsinki, Finland.
authors.forename: Kaarina
authors.initials: K
authors.lastname: Lukkari
authors.affiliation: Tvärminne Zoological Station, University of Helsinki, J.A. Palméns väg 260, FI-10900 Hanko, Finland.
authors.forename: Alf
authors.initials: A
authors.lastname: Norkko
mesh_terms: D000818:Animals; D018533:Biomass; D017753:Ecosystem; D019015:Geologic Sediments; D008954:Models, Biological; D009792:Oceans and Seas; D010100:Oxygen / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D010100:Oxygen