Peter O’Shannassy and Ian Davidson
Key words: Travelling Stock Routes and reserves, grazing management, rehabilitation, direct seeding, Biodiversity Fund.
Introduction. The travelling Stock Routes and Reserves (TSRs) in NSW comprise a network of publically owned blocks and linear routes that were set aside between 100-150 years ago in New South Wales (NSW) to allow landholders to move their livestock from their grazing properties to markets. They occur in prime agricultural land and remain under management by the state of New South Wales’s system of Local Land Services organisations (LLSs).
Since trucking of cattle is now the norm, rather than droving, the use of TSRs has gradually changed to more occasional grazing. Considering the concurrent gradual decline in biodiversity of many private properties in the same period this means that the remnant grassy woodland patches and corridors represent the most important habitats in the Riverina region and contain dozens of Threatened species and five Endangered Ecological Communities variously listed under the NSW Threatened Species Conservation Act 1995 (TSC Act 1995) and the Commonwealth EPBC Act 1999. A general recognition of the high biodiversity value of the TSRs (and need to counter degradation on many of them) has resulted in a shift in local policy and practice towards improving the condition of biodiversity in the reserves.
Works undertaken at Coreen Round Swamp and Oil Tree Reserve
Managed grazing has been applied to a number of Travelling Stock Reserves in the Riverina over a 10 year period – particularly two reserves: Coreen Round Swamp and Oil Tree reserve in the Coreen area. In 1998, condition of Coreen Round Swamp was ranked high conservation quality and Oil Tree TSR medium-high. In general, both TSRs contained tree species at woodland densities, but there was a low density of regenerating palatable trees (e.g. Bulloak and White Cypress Pine), with most species where present recorded as having sparse natural regeneration. The sites contained few regenerating shrubs (again rating sparse or absent) and exotic annual grasses were common in parts, with native grass swards patchy. Weed forbs were common
Restoration works commenced at Coreen Round Swamp and Oil Tree Reserve in 2004 and focused on:
- Manipulating the timing of grazing with selected sets of livestock at specific times to disrupt the life cycle of, particularly, annual exotic grasses to reduce these undesirable species and to prepare the way for native perennial grasses.
- Weed control – which involved multiple visits to the site throughout the year to control the various species as they emerged and prior to seed set. Spraying of herbaceous species with knockdown herbicide continued until the balance tipped and began to move towards a stronger native composition. Woody weeds such as Olive and Pepper trees were removed by hand cutting and painting with systemic herbicides.
- Reduction of grazing impacts: Livestock were camped in the TSR’s holding yards rather than under the trees at night. This was carried out to reduce physical damage to shrubs, trees and the ground layer and reduce fertility inputs to the soils under the trees; fertility levels that are known to favour weed species invasion of such areas.
Results. Monitoring using standard proformas and photopoints showed dramatic changes in both reserves; with sites previously devoid of recruitment now developing a layer of tree and shrub saplings including Bulloak and White Cypress Pine. Where once 20-30% of the Coreen Round Swamp TSR was highly degraded, being dominated by herbaceous and grass weeds, this degradation class has now reduced to less than 10%; with the remaining 90% being of high quality. Similarly Oil Tree TSR had around 30-40% in a similarly degraded condition, which has now been reduced to 10-15% of the area; with 80% being in moderate-high condition and moving towards high as the shrub layer improves. (See Figures 1-4).
Expansion of the program to hundreds of TSRs in the Riverina
Building on the success of the work at the Coreen Reserves, a five year program is well underway, funded by the Australian Government’s Biodiversity Fund in 2012. In the first for four years, 251 sites have been assessed and interventions have taken place at 102 of these sites; with a further 18 sites to be worked during the remaining funded period.
Works to date include grazing management, weed and pest species management and 960 ha of direct seeding on 70 sites. The sites are being monitored using 250 permanent photopoints located to track key vegetation structural changes, as well some transect counts of regeneration and seedling success (recruitment). Approximately 108 assessments, using the original proformas plus plot counts, are being conducted on a subset of key sites including untreated sites. Initial results of the grazing management and direct seeding are encouraging. Very successful seedling germination has occurred in the direct seeded lines on most of the seeded sites (although germination on some of the drier Boree sites took longer). Some sites have had additional seeding done in subsequent years to provide a mix of age classes. The seedlings have now developed to a range of heights, with some older seedlings up to 2 m high, while some seed continues to germinate. Some of the more mature plants have seeded in the last 12 months and the expectation is that a soil seed bank will now be starting to form.
As aggressive exclusion of birds from woodland and forest habitat by abundant Noisy Miners is listed as a Key Threatening Process (KTP) in NSW and the Commonwealth – culling of Noisy Miner (Manorina melanocephala) is being undertaken to benefit woodland bird populations. This is being done at a scale not attempted before. Baseline bird surveys have been conducted on 80 sites established over 70 reserves including on sites with and without Noisy Minor culling; and sites with shrubs and without shrubs within a range of vegetation types. The seasonal benchmark surveys have been undertaken on 8 occasions but because only one post-culling survey (spring) has been undertaken to date, it is premature to identify whether changes in bird populations have occurred yet. The surveys will continue till Autumn 2017.
Lessons learned. The results of works at the Coreen reserves are clearly a direct response to the manipulation of the timing and intensity of grazing pressure to reduce weed and allow rest for recovering native species. Achieving the desired grazing management required a paradigm shift for managers and clients. The close management of grazing, direct seeding and burning also relies on a high level of understanding and commitment by the TSR manager.
Acknowledgements. We thank Rick Webster for his seminal rapid assessments of TSRs in the late 1990s throughout southern NSW. Norman Wettenhall a visionary philanthropist and a friend of TSRs funded much of the early assessment work. The more recent funding provided by the Australian Government’s Biodiversity Fund. A number of LLS staff / Biosecurity officers are involved in the works, including Peter O’Shannassy, Michael Mullins, Stuart Watson and Roger Harris. Ian Davidson, Regeneration Solutions P/L is undertaking the vegetation assessments, Chris Tzaros, Birds, Bush and Beyond, is undertaking the bird surveys and Phil Humphries provided the mapping
Contact: Peter O’Shannassy, Murray Local Land Services (74 Short St Corowa NSW 2646, 0427010891 peter.o’firstname.lastname@example.org) and Ian Davidson Regeneration Solutions P/L (15 Weir Street Wangaratta, 0429 662 759, email@example.com).