2016 Ecological Monitoring Report 2016 Ecological Monitoring Report Bulga Coal Complex Bulga Surface Operations Pty Ltd & Bulga Underground Operations Pty Ltd July 2016 Prepared by Prepared by DnA Environmental July 2016 i 2016 Ecological Monitoring Report Disclaimer This is a report of work carried out by DnA Environmental on behalf of the Bulga Coal Management Pty Ltd and Bulga Underground Operations Pty Ltd, collectively referred to as the Bulga Coal Complex (BCC) and has been prepared according to the brief provided by the client. The information contained herein is complete and correct to the best of my knowledge. The representations, statements, opinions and advice, expressed or implied in this report are produced in good faith but on the basis that DnA Environmental are not liable (whether by reason of negligence, lack of care or otherwise) to any person for any damage or loss whatsoever which has occurred or may occur in relation to that person taking or not taking (as the case may be) action in respect of any or all of the content. Signed: Dr Donna Johnston Restoration Ecologist PhD, B.App.Sc (Hons) MEIANZ Draft submitted: 15th July 2016 Reviewed: 20th December 2016, Tom Scott (Bulga Surface Ops) Final submitted: 21st December 2016 DnA Environmental 417 Mandurama Rd Mandurama NSW 2792 Ph/Fax: (02) 63 675 251 Mobile: 0408 221 922 [email protected] ABN 19 607 392 634 Acknowledgements The field surveys and resultant report were undertaken by and prepared by Dr Donna Johnston and Andrew Johnston from DnA Environmental. Tom Scott (Bulga Open Cut) and Marty Salm (Bulga Underground Operations) provided comments on the report. Prepared by DnA Environmental July 2016 ii 2016 Ecological Monitoring Report Executive summary This is a report of work carried out by DnA Environmental on behalf of Bulga Open Cut (BOC) and Bulga Underground Operations (BUO), collectively referred to as the Bulga Coal Complex (BCC). The primary objective of the ecological monitoring program is to assess the health and condition of remnant vegetation situated within the BCC. In 2013, BCC submitted an Environmental Impact Statement (EIS) for the Bulga Optimisation Project (BOP) which is a proposed continuation of open cut coal mining operations at the existing Bulga Coal Complex to 2035. The BOP was approved in December 2014 with the realignment of the Broke Rd almost complete and construction of the western noise and visual bund being well under way during June 2016. In 2014, the ecological (and rehabilitation) monitoring program was revised such that it would also fulfil the consent conditions and regulatory approvals associated with the approval of the Bulga Optimisation Project (BOP) and BCC Biodiversity Management Plan. This year the number of ecological sites being monitored was dramatically reduced as a result of the implementation of the BOP, with some sites including BM1 and BM8 alternatively being assessed as part of the Biodiversity Offset Monitoring program. Six ecological sites remained, including: • BM4, BM10 and BM19:Eucalyptus moluccana – E. crebra (Central Hunter Grey Box – Ironbark) Woodland Endangered Ecological Community (EEC) • BM5: E. crebra – Corymbia maculata – E. moluccana (Central Hunter Ironbark – Spotted Gum – Grey Box) Forest (EEC): • BM7: Central Hunter Paperbark Soaks Woodland and; • BM23: Casuarina glauca (Central Hunter Swamp Oak) Forest. The methodology used has been consistent since 2010 and includes a combination of Landscape Function Analyses (LFA) and an assessment of ecosystem structure and habitat characteristics derived from the CSIRO Grassy woodland Benchmarking project. In 2014 however the size of the monitoring quadrats was reduced to 20 x 20m and the comprehensive soil analyses will be taken on a rotational basis to reduce monitoring effort. The ecological monitoring report provides a summary of some of the primary ecological indicators and the trends occurring since 2010 and includes a tabulated summary of all ecological indicators that were measured within a “Key Performance Indicator” (KPI) table. The rehabilitation and ecological and monitoring has been undertaken during June – July in all monitoring years and this year the field work was undertaken between 13 – 21st June. Summary of results The periods of prolonged dry conditions combined with periods of above average rainfall events experienced over the past several years has had a significant impact on the composition and diversity of the vegetation communities. The poorer growing conditions combined with increased disturbance and grazing pressures has typically had an adverse effect of the remnant vegetation and rehabilitation areas, while periods of high rainfall activity has resulted in a flush of plant growth, including weeds and has stimulated natural regeneration of a variety of native shrubs and trees. Particularly low rainfall conditions received between February and June this year has again resulted in a reduction in plant growth, floristic diversity and increased grazing and disturbances by wildlife with these seasonal conditions being reflected in the monitoring data. The monitoring sites varied in many ecological attributes largely due to their topographic position within the landscape and different vegetation assemblages. Most sites have been subjected to some degree of Prepared by DnA Environmental July 2016 iii 2016 Ecological Monitoring Report modification including clearing and grazing, with a range of other associated factors including weed invasion, soil compaction and dieback for example. Therefore in most instances, they were communities undergoing ecological recovery after a long agricultural history, but all sites were stable and generally had a functional patch area. BM5, the Corymbia maculata (Spotted Gum) woodland, continued to be the most ecologically functional site followed the E. moluccana – E. crebra grassy woodland BM19 and the Casuarina glauca forest BM23. Site BM7 the Melaleuca decora woodland had the lowest ecological function and while it had deteriorated over the past few years a marginal improvement was recorded this year. All sites contained a mature canopy cover but the species, stem densities (>5cm dbh) and trunk diameters varied significantly between sites, depending on the level of prior disturbance and regenerative capacity. Tree densities ranged from 18 (450 stems/ha) in BM10 to 148 individuals (3700 stems) in the dense regrowth Casuarina glauca forest. While the majority of the trees were live individuals, dead trees (stags) were present in low numbers across numerous ecological sites. Of the live tree densities the majority of individuals were in good to moderate health but there were also a small proportion in a state of advanced dieback in all sites. Reproductive structures and mistletoe were recorded in low numbers in numerous sites. A small proportion of eucalypts contained hollows suitable for nesting in BM10. There continued to be high variability in the densities of shrubs and juvenile trees (<5cm dbh) between sites and this year these ranged from 30 (750 stems/ha) in BM10 to 561 (14025 stems/ha). This year there was a reduction in shrub densities in BM5, BM7, BM10 and BM23. Predation by macropods and insects are likely causes for the shrub mortalities but in BM23, the Casuarina saplings had grown and were now included as part of the tree population. All sites had a shrub and/or juvenile tree population with individuals in all height categories but the vast majority of individuals were less than 0.5m in height. The diversity of shrubs and juvenile trees recorded across the range of sites ranged from a low of five in BM19 to a high of 16 in BM5. The most abundant species in any one community tended to be Acacia amblygona (Fan Wattle), A. parvipinnula (Silver-stemmed Wattle), Allocasuarina luehmannii (Bulloak), Bursaria spinosa (Native Blackthorn), Casuarina glauca (Swamp Oak), Dodonaea viscosa subsp. cuneata (Wedge-leaf Hopbush), Lissanthe strigosa (Peach Heath) and Breynia oblongifolia (Coffee Bush). Most shrubs were endemic species however 37% of the population in BM19 was the noxious weed Lantana camara with a small number (3%) also being recorded in BM5 and BM23). Limited occurrences of Withania somnifera (Winter Cherry) and Lycium ferocissimum may also have been recorded in some sites. The ground cover within the ecological sites are comprised of various combinations of dead leaf litter, perennial vegetation (<0.5m), annual plants, cryptogams and logs. Since monitoring began total ground cover has remained high in all sites but a slight decline was recorded in BM7 over the past two years as a result of macropod disturbance. Leaf litter continued to be the dominant form of ground cover and cover provided by perennial plants (<0.5m) was highly variable with high proportions of perennial grasses and herbs recorded in BM19. In the remaining sites perennial plants were less abundant. Cryptogams were recorded in low abundance in all sites except BM5 and BM10. Isolated occurrences of exotic annual weeds were recorded in BM10, BM19 and BM23. Rocks were not present but logs and small branches (>5cm) provided additional structure and habitat in sites BM5, BM7 and BM10. Most sites had scattered shrubs and low hanging tree canopies which provided at least some foliage cover in the major vertical height increments however there was limited shrubby understorey in BM10 and BM19 as these sites were open grassy woodland. All sites had a well developed mature canopy cover (>6.0m). Prepared by DnA Environmental