Natural Values of the Tasmanian Wilderness World Heritage Area 2013 Extension - Central North Sector Nature Conservation Report 20/3 DeparNaturalt mentand Cultural of Heritage PrDepartmentimaryNatural Industr of Values Primaryies, PaSurveyrk Industries,s, W• 2013ater TWWHA Parks,and En Water vExtensionironmen And Area, tEnvironment Central North Sector 1 Natural Values of the TWWHA Extension - Central North Sector Edited by Elise Dewar Document design by Land Tasmania Design Unit © Department of Primary Industries, Parks, Water and Environment This report was prepared under the direction of the Natural and Cultural Heritage Division of the Department of Primary Industries, Parks, Water and Environment (Tasmanian Wilderness World Heritage Program). Australian Government funds contributed to the project. The views and opinions expressed in this report are those of the authors and do not necessarily reflect those of the Australian Governments. ISSN: 1838-7403 (electronic) Front cover photograph by Micah Visoiu; overlooking the headwaters of Brumby Creek in the TWWHA Cite as: DPIPWE (2020). Natural values of the Tasmanian Wilderness World Heritage Area 2013 Extension – Central North Sector. Nature Conservation Report 20/3, Department of Primary Industries, Parks, Water and Environment, Hobart Natural Values Survey • 2013 TWWHA Extension Area, Central North Sector 2 KEY FINDINGS In 2013, an area of 172,276 ha was added to the Tasmanian Wilderness World Heritage Area (TWWHA). A review of the known natural values for this extension and the threats to those values highlighted significant knowledge gaps (Balmeret al., 2017). To redress these knowedge gaps, at least partially, a multi-disciplinary survey was undertaken in November 2019 to document flora, fauna and geodiversity values in part of the extension area known as the Central North Sector (CNS). Key findings and outcomes from the survey include: Natural Values • A large number of flora and fauna observations including discovery of new species, new records for the TWWHA and, records that expand the known range and distribution of various species: o 1,277 flora records representing 356 plant taxa including 22 new native species for the CNS, of which three had not been previously recorded in the TWWHA; o 73 vertebrate fauna species recorded, including six new records for the CNS; o 192 invertebrate records representing at least 84 species including 19 new records for the TWWHA extension area and seven new records for the TWWHA; o A new genus and species of millipede, which has since been formally described and named as Kebodesmus zonarius; o A new species of weevil that has yet to be described and named; o The plant Carex sp. Algonkian Rivulet was recorded for only the second time in 40 years. Samples collected will enable the formal description of the taxon which is highly restricted and confined to within the TWWHA. • 32 comprehensive flora assessments were undertaken typifying the local vegetation communities. • 10,916 ha of vegetation mapping and validation (including 3,498 ha of threatened communities). • Well-developed sandstone caves, a hitherto neglected aspect of TWWHA geodiversity, were explored and mapped on the Great Western Tiers. These are some of the best examples of sandstone caves in Tasmania. • Three previously undescribed lunettes adjacent to Little Lake were documented. Their unusual aspect and orientation provide unique indication of climatic conditions at the time of formation and warrant further study in that regard. They have been nominated for listing on the Tasmanian Geoconservation Database. Additional discovery • An old drystone structure was found at the northern edge of the Central Plateau, likely a remnant shepherd’s hut from early grazing in the first half of the 19th century. The structure had not previously been recorded on the PWS Heritage layer and has historical significance. Natural Values Survey • 2013 TWWHA Extension Area, Central North Sector 3 Threats to Natural Values WEEDS • Ragwort (Senecio jacobaea) o Ragwort is the most widespread invasive weed within the surveyed areas, with scattered individuals encountered east of Pine Lake, Westons Road and Gunns Marsh Road. o This species is wind dispersed and has a constant input of seed into these areas from large infestations which occur on the disturbed shores of Great Lake to the west. Disturbance is required for establishment and most plants are scattered populations or individuals. It is most widespread along the verges of Westons Road and Westons water race. o The species is also common around Gunns Marsh Road. In this area it has been the subject of targeted management through a Derwent Catchment Project management program since 2016, following the 2012 bushfire in this area. A coordinated weed management program for this species in this area should continue and be re-assessed on an annual basis. • Creeping thistle (Cirsium arvense) o Creeping thistle, which is also known as Californian thistle was found on the sides of Tumbledown Creek (site 10). This species is likely more widespread in this area. Creeping thistle reproduces vegetatively forming large patches that outcompete other species. It is recommended that this infestation be treated, and further mapping and treatment of infestations of the species be undertaken. Potentially this could be combined with ragwort management work in the area. • Gorse (Ulex europaeus) o Two well-established gorse bushes were found in the riparian scrub on the eastern side of the Tumbledown Creek bridge on Gunns Marsh Road (494320, 5357930). Treatment of this currently small incursion should be a management priority. o A well-established population of gorse was found above Poatina Road (site 31, 490581, 5371891) where it is mixed in the understorey of dry eucalypt forest including the threatened native vegetation community Eucalyptus amygdalina forest on sandstone. The population appears to be associated with an old service track that may have been used during road construction. Management of this site is a high priority and a targeted survey of the area for additional incursions of gorse is recommended. Natural Values Survey • 2013 TWWHA Extension Area, Central North Sector 4 PESTS • Fallow deer (Dama dama) o Deer are plentiful in the Gunns Marsh Road area. A strategy on how to best manage the species in this area is needed, as part of broader approach to managing deer in the TWWHA. • Goat (Capra hircus) o Scats were noted at Site 31 on Poatina Road, and 1km downhill which were suggestive of goat rather than deer. The habitat in the area is also not considered likely deer habitat. It is recommended that trail cameras be set up to confirm the identity of the feral bovids in the area. If goats are confirmed, eradication should be a priority. • Feral cats (Felis catus) o Cats were detected at nine of the ten camera monitoring sites and are assumed to be widespread throughout the CNS. As cats appear to be widespread and established, a control or eradication program is unlikely to be effective unless part of a broader statewide approved strategy. • European rabbit (Oryctolagus cuniculus) o Rabbit diggings and browsing were observed to have caused localised damage to sensitive vegetation communities including cushion moorlands and Poa grasslands fringing wet grassy sedgeland on the margins of Eucalyptus coccifera woodlands. HUMAN IMPACTS • Cutting and theft of firewood o Firewood hooking is very prevalent in the Gunns Marsh Road area, the scale of which suggests that this could be attributable, at least partially, to commercial operations. This is impacting significantly on the natural values in many places. The management history and mixed tenure of the area has meant that this activity has gone largely unmanaged for many years. Now that this area is within the TWWHA, management and policing of this activity should be prioritised. • Recreational activities o Areas have been cleared for unofficial camping on the shores of Little Lake near the documented lunette. This appears to have caused degradation and deflation of the ground surface, with further erosion expected due to lack of ground cover. Associated four-wheel drive tracks and rubbish dumping were also recorded in this area. Signage, closure and rerouting of the tracks may help mitigate the impacts of these activities and restoration of the area. • Access to sandstone caves o Sandstone caves off Stone Hut Track contain evidence of regular visitation, including grafitti, campfires and rubbish. These caves are locally well known and used for camping and similar activities, possibly going back many years. Any response to this is best approached via local community engagement. More generally, management of tracks on the Great Western Tiers should consider the risk that actions such as re-alignment of tracks, development of new tracks, or promotion of tracks, could put pressure on presently unaffected caves. Natural Values Survey • 2013 TWWHA Extension Area, Central North Sector 5 TABLE OF CONTENTS Key Findings . .3 Acknowledgements . .7 Terms and abbreviations . 8 1. Introduction .............................................................................9 TWWHA extension . 10 Central North Sector . .11 2. Flora values survey of the Central North sector of the TWWHA 2013 Extension ....................16 Introduction . .17 Method . .17 Results . .20 References . 39 APPENDIX 2.1 . 40 3. Vegetation Mapping ......................................................................58 Introduction . .59