Revegetating in a Drying Climate

Serpentine River, image captured by Dept. of Water and Environmental Regulation for ‘Healthy Rivers Program’, March 2023. An area that has not been observed to have such reduced flow in the past.

NRM experts across the nation are continuing to adapt restoration projects in response to climate change. Here at PHCC, we are trialling different methods of restoration in some of the most challenging project sites within the Serpentine River corridor to ensure long-term outcomes and goals of restoring its ecological value are met.

Changes in temperature and weather patterns are undoubtedly becoming more extreme and long-term across the globe. The impact is evident as we are continue to be faced with challenges each year when trying to restore ecological value in highly degraded areas. More attention to detail when planning restoration projects is now more paramount than ever due to constant shifts in weather patterns and unpredictable temperatures throughout the year. Through learnings taken from each project, we continue to adapt our management approach and celebrate the small scale successes that contribute to a greater environmental impact.

The Serpentine River, like other waterways, has been subject to significant disturbance since European settlement from agriculture, urban expansion, training and dam construction, and currently faces the pressures of rising temperatures, declined rainfall and sea-level rise (Waangaamaap Bilya Serpentine River Action Plan, 2020). Fortunately, through various healthy waterways projects coordinated by PHCC since the early 2000’s, parts of the Serpentine River that were once degraded are becoming restored and batter managed. In 2020, the ‘Waangaamaap Bilya Serpentine River Action Plan’ identified an area amongst the middle reaches of the Serpentine to undertake on-ground works to restore biodiversity. This area, referred to as the ‘Karu Bilya Restoration project site’ was considered a priority as once restored, providing a link between the river corridor and Banksia Woodland and supporting threatened species including Black Cockatoos as well as species at risk like Rakali and the Snake-necked turtle. 

On-ground actions began in late 2020 and are ongoing focusing in areas that are highly degraded; hot, sandy dry patches with limited vegetation coverage, structure and connectivity and high concentration of invasive weed species, feral animals and issues with illegal access. Specific activities such as revegetation have had to be well adapted over the past three years mainly due to the impacts of climate change in particular, low rainfall levels and extreme heat events consisting of 40 degree days consecutively. Site preparation and revegetation maintenance has become a priority to ensure the survival of seedlings. These activities have included spreading mulch in larger quantities across the site, fencing off revegetated areas rather than installing tree guards, planting each seedling with natural fertilisers and soil wetting agents, and watering every fortnight across summer. This has resulted in dramatically improved survival rates and overall establishment of the planted seedlings across the site that encompasses approximately 6 ha. These actions contribute to achieving the long-term goals of re-establishing the sites ecological value. Management of weeds is currently the priority for this year with further revegetation activities being planned for 2024.

Overcoming challenges and celebrating successes provides the motivation to continue to improve the health of our environmental assets so they can be enjoyed and sustained for future generations. Additionally, learnings from small scale projects will guide future restoration projects being undertaken across the catchment.

This project is supported by PHCC through funding from the Alcoa Foundation’s Three Rivers One Estuary Initiative.