Isaacs Ridge Nature Reserve (-35°22’0.84″, 149°7’4.8″) is one of the Canberra Nature Park around Isaacs, South Canberra. This reserve contains the various vegetation types like box gum grassy woodland and pine tree plantation. It’s also significant for threatened fauna like Speckled warbler (Chthonicola sagittata) and Varied sittella (Daphoenositta chrysoptera), the threatened flora includes Australian trefoil (Lotus australis), Black mountain leopard orchid (Diuris nigromontana), Black tongue caladenia (Caladenia congesta) and Emu-foot (Cullen tenax). Isaaca Ridge Nature Reserve sustains the local biodiversity level and maintains the environmental biomass.
Nevertheless, some environmental issues were emerged when park managers regulate this reserve. The invasive weed species has become the annoying environmental problem in Isaac Ridge Nature Reserve even all Parks in Australia. Briar rose or Sweet briar (Rosa rubiginosa) is one of the weed species in Isaacs Ridge Nature Reserve. Sweet briar is a species of rose native to Europe and western Asia. In a commercial aspect, its scent and hips would be valued, however in ecological aspect, its regards as extreme invasive species in Australia.
Sweet briar is a common sight in both the ACT area and surrounding tableland and spread into pasture, native grassland and bushland. Sweet briar is a perennial shrubs with multiply stems and can be growing 1.5m to 2m. It mainly spreads the dispersal of seed by bird eats or dropping the seed. This species prefers the well-drained area in unimproved grasslands and disturbed bushland, it’s verified that there were a bunch of sweet briar around the upper hill in Isaacs Reserve.
Sweet briar could be the environmental problems because it has the aggressive competition with other native species and provides the excellent harbour for pest animals like feral fox and rabbit. Additionally, quick growth rate and distribution of this species would reduce the presence and productivity of native pasture species as well as reduction of biodiversity.
Conservation Volunteers Australia provides many opportunities to people those love environment and biodiversity conservation. Projects take place in urban, regional and remote areas includes activities like tree plantation, seed collection, weed control etc. Fortunately, I joined in a project about sweet briar removal activity in Isaacs Reserve to enjoy contribute to biodiversity conservation, but unfortunately I also suffered in this project as well. The main task, of course, is removing the weed sweet briar by using stump treatment which is cut the stem and spray the chemical immediately to suppress it growth. The majority of the sweet briar in reserve was distributed around the upper hill due to the preferred habitat and most of them developed maturely. The native understory vegetation cannot develop very well due to less resource and space. Some of the large and hard stems weren’t easy to cut down and spray well, and always hurt by thorn! Although we knocked down the 2/3 large weed in planned area, some small or new generation remained in this site and might develop mature in couple years.
This was a rewarding and interesting working experience to me that learned how to identify the weeds and how to control them. This also helps park managers to suppress the growth of the weed and recover the environment and contributes to the biodiversity conservation to some extent. I courage people to join this project and try something different in Conservation Volunteer Australia for our environment.