Poster Presentation Australian Society for Limnology Conference 2017

10 years after active and passive riparian restoration: riparian and geomorphological condition (#104)

William Higgisson 1 , Paul O Downey 1 , Fiona Dyer 1
  1. Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia

 Riparian zones are productive and dynamic habitats, which possess a diverse range of ecological processes.  Many riparian areas across the world are degraded, affecting form and function.  Riparian restoration has, therefore, become an important objective for landscape managers.  Riparian restoration is based on an underlying assumption that on-ground works improve the ecological function of the riparian zone.  Unfortunately, long-term monitoring and assessment of ecological restoration projects is rare. This study investigates the legacy or value of ‘one-off’ restoration activities in terms of a long-term change.  Between 2000 and 2003, a large scale restoration project was undertaken in the Upper Murrumbidgee Catchment using three restoration methods (two active: planting of tubestock, and direct seeding; and one passive: fencing to exclude livestock).  The objectives were to reduce sediment and nutrient delivery into the Murrumbidgee River by controlling erosion and protecting and enhancing riparian vegetation.  In 2014, 10 years after restoration, a riparian vegetation (using RARC) and a geomorphological assessment (using ESA) were performed at a subset of sites that had undergone different restoration methods, in addition to unrestored sites.  Aerial imagery was also used to compare width of riparian canopy vegetation and projective foliage cover before restoration and ten years after.  Restoration has led to significant improvements in total riparian vegetation condition and in particular riparian attributes.  Width of riparian canopy vegetation, native mid-storey cover, native canopy cover and seedling recruitment were significantly better in sites that had been actively restored compared to the unrestored sites.  The width of riparian canopy vegetation and projected foliage cover had improved in sites in all restoration methods, especially those actively restored.  After ten years geomorphological condition was found to be significantly better in sites in all restoration methods compared to the unrestored sites, demonstrating the importance of livestock exclusion to improve bank and channel condition.