Unintended Consequences of Soil Stabilisation Methods: The Not So Lovely African Lovegrass
During, my volunteering experience at Scottsdale, a Bush Heritage reserve, I was able to see the detrimental effects of weed invasion and the hard work being undertaken to tackle this issue, to enable the ongoing restoration the Grassy Box-Gum Woodland.
The endangered Grassy Box-Gum Woodlands have been drastically reduced in area and highly fragmented due to a number of disturbances. In particular, the introduction of weeds due to inappropriate agricultural practices is noted as a major driver affecting this ecosystem. However, in this instance its seems that the detrimental effects of weed invasion was somewhat intentional. In an effort to control soil erosion the African Lovegrass (an introduced weed species) was introduced, however it seems as though the extent of which the weed would spread was under-estimated. Consequently, the African Lovegrass has now completely invaded the past cropping lands present at the Scottsdale reserve. As a result the endangered ecosystem of the Grassy Box-Gum Woodland has been detrimentally affected, especially the native grasslands which once existed on the site.
Despite the difficult task of restoring the ecosystem, with the help of numerous volunteers, the Scottsdale property continues to protect the endangered grassy box gum woodlands and temperate grasslands, but also protects many rare species and a range of interesting wildlife.
Arguably one of the most interesting yet demanding management plans being undertaken is the mass scale replanting of native species such as Acacia, Casuarina and Eucalyptus. Interestingly the plantings were all seeded from local native trees and grown in their own nursery.
In particular I was involved with a long-term study, which aims to allow natural regeneration by replanting native species with the intention of promoting a competitive advantage for native grass species. Whereby, it is hypothesised that the growth of native vegetation will drive back the invasion of African Lovegrass, therefore allowing niches for native pasture.
We surveyed groundcover both native and introduced species associated with planted trees. While the majority of the groundcover was over-run by African Love grass it was interesting to see that under the right site specific condition native grasses still had a stronghold in some areas.
I was enlightened by the work that volunteers, whatever it may be. As while calculating the ground cover of weeds may not be the most exciting thing to come to mind, when you consider that impact that this work has on the restoration of an endangered ecosystem, it becomes an inspiring experience to be apart of.
Zara Davis u5192582
Bush Heritage Australia (2014), Scottsdale Reserve. Available from http://www.bushheritage.org.au/places-we-protect/state_new_south_wales/scottsdale (Accessed 23 May 2014).
Department of Agriculture, Fisheries and Forestry (2013), African Lovegrass. Available from http://www.daff.qld.gov.au/__data/assets/pdf_file/0011/69284/IPA-African-Lovegrass-PP63.pdf (Accessed 23 May 2014).