On Friday October 6, I ventured down to Scottsdale Reserve, Bredbo, with ANU senior lecturer Dr. David Freudenberger and some fellow classmates. Our goal was to assess tree health and growth of previous tree plantings by Greening Australia and previous ANU volunteers.
Scottsdale is a privately owned reserved located near Bredbo, approximately an hour south of Canberra (Bush Heritage, 2017). The 1,328 hectares property was officially bought by Bush Heritage in 2007, with assistance from the Australian Government. Current management and work is funded by sponsors and undertaken by Bush Heritage employees and Greening Australia volunteers. This preserve aims to protect valuable Box-Gum grassy woodlands and temperate grasslands, which hold a variety of rare and vulnerable species.
Short video on the volunteer effort and work undertaken at Scottsdale. Source: BushHeritage Australia Youtube
Another goal of the reserve is the ambitious restoration of the 300ha of the property, primarily the valleys and slopes, which has been cleared and heavily cropped and grazed. Much of this area has lost any remnant overstorey trees and is now overrun by weeds. Our job was to assess many of the tree planting restoration work.
The main threat: African Lovegrass
Driving through the gates, we were surrounded by tall, sandy-coloured tussocks, little did we know these were the number one threat to Scottsdale reserve. These tussocks are an invasive, exotic weed known as African Lovegrass (Eragrostis curvula). Originally introduced for the improvement of pasture feed, driven by a need for economic growth, African lovegrass is an unpalatable, aggressive species (Firn, 2009), thriving on infertile soils and easily outcompeting native vegetation (Department of Primary Industries, 2017).
Now widespread across the Monaro, lovegrass is the main problem preventing natural revegetation in Scottsdale. The picture above shows a paddock covered wall-to-wall in lovegrass. A study by Firn (2009) has found the most successful method of removing African Lovegrass is with cattle grazing and fertiliser (yeah, like that can happen in a government-listed nature reserve) . Currently, the only grazing occurring in Scottsdale is Macropod grazing (kangaroos, wallabies). While aerial spraying is being done, not much can be done without harming the young seedlings.
Control of lovegrass is important for the eventual success of the restoration work and protection of biodiversity. The most important biodiversity to protect is Yellow-Box Gum grassy woodlands, over 90% of which has been cleared across Australia (Department of Environment, Climate Change and Water, 2010). There are also a number of vulnerable and sensitive species to protect, such as the Speckled Warbler, Golden Sun Moth and a remnant Silver-Leafed Mountain gum.
The restoration process
The extent of the restoration process was evident from the moment we pulled up to the main office (a former shearing shed), passing a storage shed and greenhouse filled to the brim with acacia and eucalypt seedlings, the seeds for which were sourced locally. Phil Palmer, manager of Scottsdale reserve, then showed us maps of the property, where restoration scars could be seen all along the valley floors.
This restoration work began in 2007, reintroducing key over storey species, including Acacias and various eucalypts such as Snow Gum, Candlebark and Yellow-Box. These plantings we done with various methods, including direct planting of seedlings, performed by ANU volunteers and Greening Australia. Click here for a previous blog post on some of this work.
The most successful restoration method so far has been scraping off the top 10cm of soil and direct seeding native ground cover. This has been done in small plots, with one already showing native eucalypt regeneration. The main factor for this methods success is removing the nutrient-rich top soil and eliminating African Lovegrass. While other methods have been less successful, native vegetation can still be observed in the shallow soils of rocky outcrops.
What we were assessing, however, were the direct plantings in the Southern portion of the reserve. These plantings were done in rows, with a mix of eucalyptus and acacias species.
This year, we observed significant impact on Acacia species, with individuals, many of which that had a perfect health score last year, were almost dead. Both David and the employees at Scottsdale noted how exceptionally dry this year has been, and how the plants have suffered. This brings up not only how planting success is extremely variable, but also how uncontrollable factors, including climate, can potentially devastate planting efforts.
Finally, another aspect of restoration we saw, was the removal of rabbits and rabbit warrens. While this is an important control, it is clear a similar effort should be put towards macropods. In the patches where native grasses could come up amongst the lovegrass, they were nibbled to a small nub, with some eucalyptus plantings also suffering. Kangaroo culling, however, still remains an extremely controversial subject.
Other key projects: Reintroductions and Connectivity
While restoration is a key goal at Scottsdale, it is a unique property, with a diverse range of other projects and initiatives at work.
This reserve is also the keystone property of the Kosciusko2Coast project, an initiative aimed at connecting remnant woodlands and grasslands from the Brindabella’s to Kosciusko to the far south Coast of NSW (Landcare NSW, 2016).
Work is also being done along the Murrumbidgee, which borders the northern part of the property. This includes assisting the recovery of native fish through European Carp and Willow tree control.
Finally, the reserve is also the site of a number of research projects. One project has seen the relocation of a doomed Striped Legless Lizard population from Canberra to the reserve, with the reserve having the potential for a number of honours, masters and PhD projects.
How can you help?
The future of Scottsdale relies on the generosity and support of the community. What I learnt from this experience is that restoration is a process of trial and error, an expensive learning process which can (and probably will) take hundreds of years. It is impacted by exotic weeds, feral animals, overgrazing and climate, but I believe projects like Scottsdale will inspire and educate on the future restoration of grasslands and woodlands. If you would like to donate or volunteer with Bush Heritage Australia, please follow the links below.
Bush Heritage. 2017. Scottsdale [Online]. Available: https://www.bushheritage.org.au/places-we-protect/new-south-wales/scottsdale [Accessed 8 October 2017].
Department Of Environment, Climate Change and Water. 2010. National Recovery Plan for White Box – Yellow Box – Blakely’s Red Gum Grassy Woodland and Derived Native Grassland. Department Of Environment, Climate Change and Water, Sydney.
Department Of Primary Industries. 2017. African lovegrass (Eragrostis curvula) [Online]. NSW Government. Available: http://weeds.dpi.nsw.gov.au/Weeds/Details/3#control [Accessed October 8 2017].
Firn, J. 2009. African lovegrass in Australia: a valuable pasture species or embarrassing invader? TG: Tropical Grasslands, 43, 86.
Landcare NSW. 2016. Kosciuszko to Coast (K2C) [Online]. Available: http://www.landcare.nsw.gov.au/groups/kosciuszko-to-coast [Accessed 8 October 2017].