If you build it, will they come? Assessing the effectiveness of kelp forest restoration in restoring key ecosystem functions and servicesMacroalgae and Ecosystem Services (sponsored by Annals of Botany)

Aaron M Eger^1,2, Paul Carnell³, Hartvig Christie⁴, Joao Nuno Franco⁵, Alejandra Gonzalez⁶, Lynn Lee⁷, Ezequiel Marzinelli⁸, Kelsey Irene Miller⁹, Alejandro Perez-Matus¹⁰, Adriana Verges²

¹Kelp Forest Alliance, Australia - ²University of New South Wales, Australia - ³Royal Melbourne Institute of Technology University, Australia - ⁴NIVA, Norway - ⁵University of Porto, Portugal - ⁶Universidad de Chile Santiago, Chile - ⁷Parks Canada, Canada - ⁸Sydney University, Australia - ⁹University of Auckland, Australia - ¹⁰Pontifica Universidad Catolica de Chile, Chile

Kelp forests, primarily composed of species within the orders Laminariales and Fucales, are foundational marine ecosystems that provide essential services, including carbon sequestration, biodiversity support, and fisheries enhancement. However, widespread degradation driven by climatic and anthropogenic pressures threatens their ecological and economic value. The field of kelp forest restoration is now growing in scope with new projects launching at a much faster rate than in the past. Still, questions persist about the efficacy of kelp forest restoration, not only in restoring the kelp habitat but in restoring the ecosystem function and carry on ecosystem services of the local seascape. This study evaluates the ecosystem functions and services provided by restored kelp forests compared to those in healthy and degraded states. By examining variations across biogeographical regions, ecological interactions, and temporal scales, we identify critical drivers influencing service recovery. Our findings will examine whether restoration efforts can not only rehabilitate ecosystem services but also enhance human wellbeing in the face of ongoing environmental change. These results will inform kelp forest conservation and restoration strategies worldwide.