Density-depedent impacts of an invasive foundation species on multiple functions in a coastal ecosystem

Background/Question/Methods

Humanity depends on ecosystems to maintain many different functions at the same time.  Invasive species are widely considered a threat to the provisioning of these important functions (e.g. wave attenuation, fisheries production).  Recent concept papers, however, suggest impacts of biological invasions may vary greatly depending on ecological context and function(s) measured.  We experimentally tested this idea by examining the density-dependent effects of an invasive, habitat-forming foundation species on the ability of tidal flats to provide seven ecosystem functions simultaneously. 

Results/Conclusions

Our findings demonstrate that invasion by foundation species that create three-dimensional habitat can increase the production of multiple ecosystem functions and stabilize their production through time.  The generation of these functions is often non-linear and saturates quickly at lower densities.  These results suggest that where native foundation species are absent, the introduction of non-natives has the potential to profoundly restore the overall delivery of those functions.