Roey Teiwsen, Conservation Volunteers Australia and Gabriel Anderson, GER Hunter Stepping Stones.
The Lower Hunter Region stretches from Nelson Bay and Maitland Vale, through Newcastle and Cessnock to include the Lake Macquarie area and down to the Watagans National Park. The Lower Hunter Stepping Stones project aims to strengthen ecological connectivity between the Watagans National Park and Pambalong and Hexham Swamp Nature Reserves. By enhancing the biodiversity and ecological health of existing bushland, as well as creating new connections between habitat fragments, the project will increase ecosystem resilience to climate change.
A large proportion of the regeneration work was undertaken in the Mount Vincent and Brunkerville localities, rehabilitating remnant fragments and enhancing connectivity through vegetation corridors and stepping stone plantings (Figure 1). Situated about 40 kilometres west of Newcastle, these areas back onto Heaton and Awaba State Forests and Watagans National Park. Cooperation from the private landholders in these areas has been vital in the success of rehabilitating adjacent habitat patches. In 2013- 2014, exotic weed management was the primary focus, with a small number of planting projects being undertaken. Future plantings are planned, as well as ongoing weed management, to improve connectivity and resilience across the area.
Figure 1: Map of areas worked in the Mount Vincent and Brunkerville localities. Areas outlined in orange are weed management, those outlined in green are planting projects and red outlines are property boundaries.
A variety of invasive species were treated across these sites, including Wild Tobacco, Blackberry, Senna, exotic vines and camphor laurels. However, the biggest problem affecting biodiversity and ecological health in the lower hunter is the overwhelming presence of Lantana (Lantana camara). Growing in dense thickets and consuming the understorey native species, Lantana prevents the growth of native vegetation and seedlings though suppression and allelopathy – chemically preventing the germination of other plant species.
Each property was assessed by the Stepping Stones Project and the Conservation Volunteers Bush Regeneration team designed individual approaches for each site. A variety of methods were used to control the weeds, including manual removal, cut & paint or scrape & paint, foliar spraying and splatter gun spraying. Manual removal involves pulling the weeds from the roots and stacking or bagging the plant matter. Cut & paint is where the plant is cut as close to ground level as possible, then immediately applying 100% Glyphosate. Scrape and paint is usually the method of choice for vines and scramblers, and involves scraping a portion of the stem and, again, immediately applying 100% glyphosate. Foliar spraying is the diluted application of a selected chemical to the entirety of a plant’s foliage (usually 2% 360g/L Glyphosate), and splatter gun spraying is a higher concentration of chemical (usually 10% 360g/L Glyphosate) at a much lower volume. The splatter gun spraying method is the most cost and time effective way of controlling high density lantana.
Many of the properties where lantana was the primary focus, the lantana was growing at a very high density. The approach in these situations was to cut tracks through the dense areas with a machete and walk back through the tracks splatter gun spraying the patches. Many factors affected the result of this method, including presence of morning dew, very high temperatures or stressed plants.
John and Lillian Thurlow’s Mount Vincent property is part of a key corridor linking the Watagans National Park through Mount Vincent to Wallace Creek. Much of the creek line as well the understorey of the beautiful sclerophyll forest is inundated with dense lantana thickets, threatening the biodiversity of native flora and fauna. Due to the high density of lantana in many areas, the Conservation Volunteers Bush Regeneration team primarily used splatter gun spraying to treat as much of the lantana as possible with the time they had. Results were mixed, as in some areas the forest held morning dew for an extended time and the lantana may not have been dry enough for effective chemical intake. Drier areas of the property took to treatment much better, here most lantana plants died back with only a few unreachable sections untreated, see Photos 1 and 2 below. Follow-up treatment has now occurred and the landholder will be able to continue the great work the Stepping Stones project has started.
Photos 1 and 2: Before and after comparison of Lantana after splatter gun treatment at the Thurlow’s property.
This project is supported by funding from the Australian Government