The weather was cooperative last Friday (7th of October) when Dr. David Freudenberger took me, Molly and Paul on a field adventure in Scottsdale Reserve in New South Wales. After a fifty-minute drive from Canberra, we arrived at this 1,328 hectare property which is currently a hotspot of environmental conservation activities and biodiversity studies (Bush Heritage Australia, 2016). On contrary to the clear sky in Canberra, it was cloudy in Scottsdale that day and saved us from sweating too much after working in the field for hours.
Approximately 300 hectares of Box Gum Grassy Woodlands in Scottsdale Reserve suffered from degradation caused by years of hobby farm operations. In fact, David didn’t forget to remind us during lunch that the cosy cottage we were chilling in was a modified woolshed which still smells like sheep. To test the effectiveness of restoring the threatened ecological community, Bush Heritage Australia, which is the owner of Scottsdale Reserve, partnered with Greening Australia and David from ANU to start a large-scale revegetation project three years ago. The project is jointly funded by Australian Government and Bush Heritage, while Greening Australia helped with organising voluntary tree planting activities and provided more than half of tree seedlings from their nursery.
Our job that day was simple. We estimated health score and measured the diameter at 10 centimetres above ground of planted trees and shrubs along 26 transects. Each transect was 100 metres long with random numbers of plants from a selected range of species. The planted species include Acacia rubida, Acacia dealbata, Bursaria spinosa, Acacia melanoxylon, Cassinia longifolia, Eucalyptus Bridgesiana, Eucalyptus pauciflora, Eucalyptus melliodora, general shrub, etc. Health score is an important indicator of the effectiveness of this restoration. A score of 2 means robust health/growth whilst a score of 0 refers to death of the plant. According to David, the initial success of this trial is a survival rate higher than 80% over the first few years. Having done calculations based on data of the last two years, I found a survival rate of approximately 92.9% in the restored plants, which is very high compared to the 80% threshold.
In the long run, the success of this restoration work is the planted native species out-competing the rampant African lovegrass in the studied area, allowing more native grasses and wildflowers to thrive. African lovegrass came into Australia prior to 1900s (NSW Government, 2014), and was introduced to Scottsdale in the 1930s for grazing purposes according to David. Currently it is deemed as a weed that has dominated the native grassland in Scottsdale. However a coin has two sides, the decision of removing African lovegrass can be a tricky one due to the potential positive relationship between this plant and some reptile species. Reptiles prefer taller grasses that can provide them with protection and shades, and studies conducted in Scottsdale show that African lovegrass, which usually grows into tall clusters, appeals to reptiles including the reintroduced Striped Legless Lizard. Striped Legless Lizard is listed as Vulnerable in EPBC Act (Australian Government, 2016), and we briefly visited the study site that investigates the preferred habitat of this species.
Working with David and my classmates was absolutely fun and rewarding. The most important take-away lesson I have learned is that conservation strategies are not always black or white answers, the controversial ecological function of African lovegrass is a perfect example that shows the complexity of biodiversity studies. Last but not least, this is the first environmental volunteering experience in my life. I realised that the actual process of researches in the Environment field involves a great amount of hard work, both mentally and physically. My respect to people who have chosen this path to be their career have raised to a higher level than ever before.
Mengxian Hu U5464870
Australian Government. (2016). Delma impar in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=1649
NSW Government. (2014). African lovegrass (Eragrostis curvula). Department of Primary Industries. Available from: http://weeds.dpi.nsw.gov.au/Weeds/Details/3
Bush Heritage Australia. (2016). Restoration ecology. Scottsdale Reserve. Available from: http://www.bushheritage.org.au/what-we-do/science/themes/restoration