Oral Presentation Freshwater Sciences 2023

Incorporating biotic interactions in restoration actions will lead to better biodiversity outcomes – a synthesis of experiments. (#417)

Helen J Warburton 1 , Catherine M Febria 1 2 , Issie C Barrett 1 3 , Imogen B Eglesfield 1 4 , Kate J Hornblow 1 5 , Amy J van Lindt 1 , Bridget E White 6 7 , Jon S Harding 1 , Kristy L Hogsden 1 8 , Elizabeth S Graham 1 9 , Angus R McIntosh 1
  1. University of Canterbury, Christchurch
  2. University of Windsor, Windsor
  3. Lincoln University, Lincoln
  4. Ministry for Primary Industries, Wellington
  5. Boffa Miskell, Christchurch
  6. University of Tasmania, Hobart
  7. University of Canterbury, Christchurch, CANTERBURY, New Zealand
  8. NIWA, Christchurch
  9. NIWA, Hamilton

Urgent action is required to restore damaged ecosystems, with the United Nations declaring 2021-2030 a decade of restoration. However, efforts to restore biodiversity in freshwater ecosystems have had limited success. One likely contributing factor is a recent, more singular, focus on physical habitat improvements (e.g. bank-side planting, channel reconfiguration, in-stream habitat additions). While an important first step, focusing solely on physical habitat excludes opportunities to actively plan for biotic restoration. We will present a synthesis of multiple experiments demonstrating that degraded invertebrate communities are resistant to reintroductions of native fauna, therefore ignoring biotic interactions and assuming biodiversity will improve passively post habitat improvements will increase the chance of restoration failure. We tease apart the respective roles of competition and priority effects in driving outcomes, and also show that predation plays an important role in potential restoration success. Moreover, we will highlight that biotic restoration success could be enhanced through more careful consideration of the specific community composition of reintroduced organisms, including invertebrate and predator traits, as well as the sequence and magnitude of these reintroductions.