In our last newsletter we reported on a burning trial conducted on three springs on the Finniss Springs property, Bopeechee, Beatrice and a spring described as HBO 004, in May 2016. This trial was undertaken as part of DEWNR’s Desert Jewels project as an initial effort to assess the potential ongoing role of fire in the management of reeds, particularly Phragmites, in mound springs. Prolific growth of Phragmites has occurred at many springs that have been protected from cattle grazing to the apparent detriment of other wetland species. DEWNR and FOMS have been considering options for the active management of this prolific reed growth, with fire and periodic grazing (see also the Billa Kalina article) being two options for consideration.
In July 2016 a FOMS group visited Finniss Springs and noted quite strong regrowth of Phragmites just 7 or 8 weeks after the trial burn. At the time, FOMS carried out some vegetation monitoring, measuring density and height of regrowth.
However, in June 2017 a further FOMS inspection showed that the regrowth of Phragmites is being severely grazed by horses. The photos included here of Spring HBO 004 illustrate the situation. This has significantly complicated the monitoring program. While the horses remain in the area we are not simply monitoring the response of Phragmites to a trial burn but monitoring a combination of regrowth from fire and grazing impacts. Some discussion will be needed about the value of continuing the current vegetation monitoring or the need to adopt a different approach.
Over the past three years the Department of Environment, Water and Natural Resources (DEWNR), in collaboration with FOMS and others, has been conducting the Desert Jewels project aimed at improved management of mound springs to achieve conservation objectives. A primary area of interest has been the management of reeds (Phragmites), which have tended to proliferate in springs fenced to exclude stock. While Phragmites is a natural component in the landscape in mound spring country, it is thought that many decades of cattle intrusion into the mound springs has elevated nutrient levels and, when stock are excluded from the springs, the elevated nutrients have favoured prolific regrowth of Phragmites at the expense of other vegetation. It has been postulated that burning of the Phragmites, possibly in line with traditional Aboriginal burning practices, might be a useful management tool to help restore a more diverse vegetation cover at these springs. The burning process may help to hasten a decline in nutrient levels in these springs.
With this in mind, DEWNR collaborated with the local Arabana people and with FOMS personnel in June 2016 to burn two Phragmites springs on Finniss Springs (Bopeechee Spring and a spring described as HBO004). A trial burn was also conducted at nearby Beatrice spring – a spring with bulrush (Typha) cover rather than Phragmites. Also participating was Dr Jasmin Packer, Postdoctoral Fellow, School of Biological Sciences, University of Adelaide. Dr Packer is working on a project on Phragmites management at a national and international scale and is keen to integrate the information from the mound spring burning trials into her own project.
Despite the regular and sometimes heavy rainfall in the Far North during 2016, the burning of Phragmites at Bopeechee and HBO004 springs was very successful burning virtually all above-ground or above-water vegetation and leaving a thick mat of ash.
The burning of the Typha spring (Beatrice) was less successful. The Typha was quite green and only a partial burn was possible. In the last week of July 2016 FOMS members Colin Harris, Bruce Gotch, Claire Bockner and Simon Lewis, along with Arabana elder Dean Stuart, paid another visit to Beatrice, Bopeechee and HBO004 springs. The group was interested to note quite prolific regrowth of Phragmites at Bopeechee and HBO004 just six weeks after the burns – with up to 70 Phragmites stems per square metre up to 0.65m high. The group repeated a number of one metre square quadrats at these springs to measure the extent of regrowth.
It is intended that monitoring will continue at these springs for several years to assess the longer term response of the reeds and of other vegetation associated with the springs. This will link in with monitoring at other springs – such as Outside and the Fountain, on the Peake – where the Phragmites appears to be in a state of natural decline. Another aspect to be considered is whether repeated burning at a particular spring – rather than a single one-off burn – should be trialled as a management option.