Category Archives: Planning, monitoring & assessment

A framework and toolbox for assessing and monitoring swamp condition and ecosystem health

Key words: Upland swamp, stygofauna, sedimentology, ecosystem processes, biological indicators, geomorphology

Introduction. Upland swamps are under increasing pressure from anthropogenic activities, including catchment urbanization, longwall mining, and recreational activities, all under the omnipresent influence of global climate change. The effective management of upland swamps, and the prioritisation of swamps for conservation and restoration requires a robust means of assessing ecosystem health. In this project we are developing a range of ecological and geomorphic indicators and benchmarks of condition specifically for THPSS. Based on a multi-metric approach to ecosystem health assessment, these multiple indicators and benchmarks will be integrated into an ultimate index that reflects the health of the swamp.

In this project we have adopted (and modified) the definition of ecosystem health applied to groundwater ecosystems by Korbel & Hose (2011). We define ecosystem health of a swamp as, i.e., “an expression of a swamp’s ability to sustain its ecological functioning (vigour and resilience) in accordance with its organisation while maintaining the provision of ecosystem goods and services”.

Design. Our approach to develop indicators of swamp health followed those used to develop multimetric indices of river and groundwater ecosystem health (e.g. Korbel & Hose 2011). We used the ‘reference condition’ approach in which a number of un- or minimally disturbed swamps were sampled and the variation in the metric or index then represents the range of acceptable conditions (Bailey et al. 1998; Brierley & Fryirs 2005).

We focused initially on swamps in the Blue Mountains area. Reference (nominally unimpacted) and test sites with various degrees and types of impacts were identified using the database developed by the concurrent THPSS mapping project (Fryirs and Hose, this volume).

Following our definition of ecosystem health, we selected a broad suite of indicators that reflect the ecosystem structure (biotic composition and geomorphic structure) and function, including those relating to ecosystem services such as microbially-mediated biogeochemical functions, geomorphic processes and hydrological function, as well as the presence of stressors, such as catchment changes. Piezometers and dataloggers have been installed in a number of swamps to provide continuous data on groundwater level fluctuations and sediment cores taken at the time of piezometer installation have provided detailed information on the sedimentary structure, function and condition of the swamps.

Results. Intact and channelised swamps represent two geomorphic condition states for THPSS. Not surprisingly, variables reflecting the degree of catchment disturbance (such as urbanization) were strongly correlated with degraded swamp condition. Variables related to the intrinsic properties of swamps had little relationship to their geomorphic condition (Fryirs et al. 2016). Intact and channelized swamps present with typically different sediment structures. There were significant differences in the texture and thickness of sedimentary layers, C: N ratios and gravimetric moisture content between intact swamps and channelised swamps (Friedman & Fryirs 2015). The presence and thickness of a layer of contemporary sand in almost all channelised swamps and its absence in almost all intact swamps is a distinctive structural difference.

Disturbed swamps have poorer water quality at their downstream end, and associated with this, lower rates of organic matter processing occurring within the streams (Hardwick unpublished PhD Data). Similarly, the richness and abundance of aquatic invertebrates living within swamp sediments (stygofauna) is poorer in heavily disturbed swamps than in undisturbed or minimally disturbed areas (Hose unpublished data).

Within the swamp sediments, important biogeochemical processes, such as denitrification and methanogenesis, are undertaken by bacteria. In this study we are measuring the abundance of the functional genes such as a surrogate for functional activity within the swamp sediments. There is large spatial variation in the abundance of functional genes even within a swamp, which complicates comparisons between swamps. Within our focus swamp, the location closest to large stormwater outlets had different functional gene abundances, in particular more methanogens, than in less disturbed areas of the swamp. There were greater abundances of denitrification genes, nirS and nosZ, in shallower depths despite denitrification being an anoxic process, which may reflect changes in the surficial sediments due to disturbance. Overall however, the abundance of functional genes seem to vary more with depth than with location, which means that comparisons between swamps must ensure consistency of depth when sampling sediments (Christiansen, unpublished PhD data).

The list of indicators currently being tested in this project and by others in this program (Table 1) will be refined and incorporated into the final assessment framework. Thresholds for these indicators will be determined based on the range of conditions observed at the reference sites. The overall site health metric will reflect the proportion of indicators which pass with respect to the defined threshold criteria. At this stage, the final metrics will be treated equally, but appropriate weightings of specific metrics within the final assessment will be explored through further stakeholder consultation.

Stakeholders and Funding bodies. This research has been undertaken as PhD research projects of Kirsten Cowley, Lorraine Hardwick and Nicole Christiansen at Macquarie University. The research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program. This project was also partly funded by an ARC Linkage Grant (LP130100120) and a Macquarie University Research and Development Grant (MQRDG) awarded to A/Prof. Kirstie Fryirs and A/Prof. Grant Hose at Macquarie University. We also thank David Keith, Alan Lane, Michael Hensen, Marcus Schnell, Trevor Delves and Tim Green.

Contact information. A/Prof. Grant Hose, Department of Biological Sciences, Macquarie University (North Ryde, NSW 2109; +61298508367; grant.hose@mq.edu.au); and A/Prof. Kirstie Fryirs, Department of Environmental Sciences, Macquarie University (North Ryde, NSW 2109; +61298508367; kirstie.fryirs@mq.edu.au).

Table 1. List of indicators of swamp condition that are being trialled for inclusion in the swamp health assesment toolbox.

Functional indicators table

Testate amoebae: a new indicator of the history of moisture in the swamps of eastern Australia

Key words: Temperate Highland Peat Swamps Sandstone

Introduction. Swamps are an ideal natural archive of climatic, environmental and anthropogenic change. Microbes and plants that once inhabited the swamps are transformed and accumulate in undisturbed anoxic sediments as (sub)fossils and become useful proxies of the past environment. Since these systems are intrinsically related to hydrology, the reconstruction of past moisture availability in swamps allows examination of many influences, including climate variability such as El Nino-induced drought. It can also provide baseline information: long (palaeoenvironmental) records can reveal natural variability, allow consideration of how these ecosystems have responded to past events and provide targets for their restoration after anthropogenic disturbance.

Testate amoebae are a group of unicellular protists that are ubiquitous in aquatic and moist environments. The ‘tests’ (shells) of testate amoebae preserve well and are relatively abundant in organic-rich detritus. Testate amoebae are also sensitive to, and respond quickly to, environmental changes as the reproduction rate is as short as 3-4 days. Modern calibration sets have demonstrated that the community composition of testate ameobae is strongly correlated to moisture (e.g. depth to water table and soil moisture) and this allows statistical relationships to be derived. These relationships have been used extensively in European research for the derivation of quantitative estimates of past depth to water table and hence moisture availability.

Although a suite of different proxies have used to reconstruct aspects of past moisture availability in Australia (e.g. pollen, diatoms, phytoliths) very little work on testate amoebae has occurred to date. This project aims to address this deficiency by examining testate amoebae in several ecologically important mires in eastern Australia including Temperate Highland Peat Swamps on Sandstone (THPSS), an Endangered Ecological Community listed under the Environment Protection and Biodiversity Conservation Act 1999 and as a Vulnerable Ecological Community under the NSW Threatened Species Conservation Act 1995.

The project specifically aims to develop a transfer function linking modern samples to depth to water table in THPSS and to then apply this to reconstruct palaeohydrology over the last several thousand years. Our ultimate aims are to use this research to consider the nature and drivers of past climate change and variability and to also address issues associated with recent human impacts. The analysis of testate amoebae will allow us to consider changes in THPSS state, accumulation and stability over centuries-to-millennia, and this will provide context for recent changes, recommendations for the management of peaty swamps on sandstone and analytic tools for assessing whether remediation is resulting in significant improvement on eroding or drying swamps.

Work Undertaken and Results to Date. Research linking testate amoebae and depth to water table in Europe and North America has mostly been undertaken in ombrotrophic (rain-fed) mires. These are distinctly different to THPSS and related communities of the Sydney Basin, which are often controlled by topography (topogeneous mires). In these environments various sediments are known to build up sequentially through time and the minerogenic-rich sediments of the THPSS have resulted in several challenges in our preliminary work. As an example, standard laboratory protocols do not remove mineral particles and these can obscure and make testate amoebae identification difficult. We have since developed a new laboratory protocol and results are promising. We have also been struck by the distinct Northern Hemisphere bias to testate amoebae research: as an example, the Southern Hemisphere endemic species Apodera (Nebela) vas that has been common in our THPSS samples is not included in the most popular guideline book (https://www.qra.org.uk/media/uploads/qra2000_testate.pdf).

Despite the new laboratory protocols we have found that testate amoebae are relatively scarce in THPSS environments. Table 1 outlines the species we are encountering in modern (surface) samples of THPSS and in the high altitude Sphagnum bogs of the Australian Capital Territory: we are finding greater abundance and species richness in the bogs of the ACT.

This project commenced in 2015 and will run until 2017.

Stakeholders and Funding. This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program.

Contact information. The project testate amoebae as indicators of peatland hydrological state’ is jointly being undertaken by: A/Prof Scott Mooney (School of Biological, Earth and Environmental Science, UNSW +61 2 9385 8063, s.mooney@unsw.edu.au), Mr Xianglin Zheng (School of Biological, Earth and Environmental Science, UNSW, +61 2 9385 8063, xianglin.zheng@unsw.edu.au) and Professor Emeritus Geoffrey Hope (Department of Archaeology and Natural History, School of Culture, History, and Language, College of Asia and Pacific, The Australian National University, +61 2 6125 0389 Geoffrey.Hope@anu.edu.au).

Table 1. A list of the testate amoebae species found in THPSS environments of the Sydney region and in the high altitude bogs of the ACT. (Those with a ++ are more common.)

Mooney table1

A novel multispecies approach for assessing threatened swamp communities

Hannah McPherson and Maurizio Rossetto,

Key words:   Swamp conservation, chloroplast DNA, genetic diversity, landscape connectivity

Introduction. Little is known about the historical or present-day connectivity of Temperate Highland Peat Swamps on Sandstone (THPSS) in the Sydney Basin (NSW). Recent technological advances have enabled exploration of genetic complexity at both species and community levels.  By focusing on multiple plant species and populations, and investigating intraspecific gene-flow across multiple swamps, we can begin to make generalisations about how species and communities respond to change, thereby providing a solid scientific basis from which appropriate conservation and restoration strategies can be developed.

The study area comprised eight swamps distributed across four sites along an altitudinal gradient: Newnes (1200m); Leura (900m); Budderoo (600m); and Woronora (400m), see figure 1.

Map of the Sydney Basin region showing four study sites and eight swamps. Greyscale shows altitude gradient.

Map of the Sydney Basin region showing four study sites and eight swamps. Greyscale shows altitude gradient.

The aims were:

  • To assess the relative genomic diversity among target species representing a range of life-history traits. This was achieved by sequencing chloroplast DNA and detecting variants in pooled samples from 25 species commonly occurring in swamps.
  • To explore geographic patterns of diversity among swamps and across multiple species by designing targeted genomic markers and screening variants among populations within and between sites (for ten species occurring in up to 8 swamps).
  • To develop a set of simple, effective and standardised tools for assessing diversity, connectivity and resilience of swamps to threats (from mining to climate change).
Fig 2. Broad Swamp, Newnes Plateau (Maurizio Rossetto)

Fig 2. Broad Swamp, Newnes Plateau (Maurizio Rossetto)

Our study comprises three main components:

1. Species-level assessment of genetic variation of swamp species

We have taken advantage of new available methods and technologies (McPherson et al. 2013 and The Organelle Assembler at http://pythonhosted.org/ORG.asm/) to sequence and assemble full chloroplast genomes of 20 plant species from swamps in the Sydney Basin and detect within and between-population variation. This enabled a rapid assessment of diversity among representatives of 12 families and a broad range of life-history traits – e.g. table 1. We are currently finalising our bioinformatic sampling of the data to ensure even coverage of chloroplast data across the species, however these preliminary data show that relative estimates are not a product of different amounts of chloroplast data retrieved (e.g. for the seven species with sequence length greater than 100,000 base pairs variation ranges from absent to high).

2. Swamp-level assessment of variation and connectivity using three target species – Baeckea linifolia (high diversity), Lepidosperma limicola (low diversity) and Boronia deanei subsp. deanei (restricted and threatened species).

From the initial species-level study we selected three very different species for detailed population-level studies. We designed markers to screen for variation within and among sites and explore landscape-level connectivity. We identified the Woronora Plateau as a possible refugium and we have uncovered interesting patterns of gene-flow on the Newnes Plateau. Two species, Lepidosperma limicola and Baeckea linifolia seem able to disperse over long distances while Boronia deanei subsp. deanei showed unexpected high levels of diversity despite very limited seed-mediated gene-flow between populations. Its current conservation status was supported by our findings. A unique pattern was found for each species, highlighting the need for a multispecies approach for understanding dynamics of this system in order to make informed decisions about, and plans for, conservation management.

3. Multi-species approach to assessing swamp community population dynamics

Since the population study approach proved successful we expanded our study to include population studies for a further ten species. This required development of new Next Generation Sequencing (NGS) approaches applicable to a wide range of study systems. This kind of approach will allow us to make informed generalisations about swamp communities for conservation management planning.

Fig 3. Paddy’s Swamp, Newnes Plateau (Anthea Brescianini)

Fig 3. Paddy’s Swamp, Newnes Plateau (Anthea Brescianini)

Table 1. Preliminary results showing relative chloroplast variation among 25 swamp species. Sequence length is in base pairs (bp) and relative level of variation was calculated as sequence length divided by number of variants to obtain an estimate of number of SNPs per base pair.  Relative variation was then categorised as: High (one SNP every <1,000 bp); Moderate (one SNP every 1,000 – <5,000 bp); Low (one SNP every 5,000 – <10,000 bp); Very low (one SNP every >10,000 bp); or absent (no SNPs).

table

Fig 4. Banksia ericifolia (Maurizio Rossetto)

Fig 4. Banksia ericifolia (Maurizio Rossetto)

Results to date. We have assembled partial chloroplast genomes of 20 plant species from THPSS in the Sydney Basin and categorised relative measurements of diversity. Preliminary data from the three target species highlighted the need for multispecies studies and we are now finalizing our results from an expanded study (including 13 species) in order to better understand connectivity and resilience of THPSS and provide data critical for more informed conservation planning. We have produced unique, simple methods for assessing genetic diversity and understanding dynamics at both the species and site levels.

Lessons learned and future directions. We found that individual species have unique patterns of genetic variation that do not necessarily correspond with phylogeny or functional traits and thereby highlight the benefit of multispecies studies. We have developed a unique, simple method for screening for genetic variation across whole assemblages which can be applied to many study systems. Since our data capture and analysis methods are standardised it will be possible in the future to scale this work up to include more species and/or more geographic areas and analyse the datasets together to address increasingly complex research questions about the resilience of swamps in a changing landscape.

Stakeholders and Funding bodies. The following people have contributed to many aspects of this research, including design, fieldwork and data generation and analysis: Doug Benson and Joel Cohen (Royal Botanic Gardens and Domain Trust), Anthea Brescianini and Glenda Wardle (University of Sydney), David Keith (Office of Environment and Heritage).

This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd. Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program.

Contact. Hannah McPherson, Biodiversity Research Officer, Royal Botanic Gardens and Domain Trust, Mrs Macquaries Road, Sydney 2000; Tel: +61292318181 Email: hannah.mcpherson@rbgsyd.nsw.gov.au

Hydrology of Woronora Plateau Temperate Highland Peat Swamps on Sandstone

William C Glamore and Duncan S Rayner

Key words: water balance, groundwater, soil, subsidence, under mining

Introduction. The Temperate Highland Peat Swamps on Sandstone (THPSS) ecological community consists of both temporary and permanent swamps developed in peat overlying Triassic Sandstone formations at high elevations, generally between 400 and 1200 m above sea level on the south-east coast of Australia. THPSS are listed as an endangered ecological community (EEC), threatened by habitat destruction and modification of groundwater and hydrology. The primary impact of longwall mining is to swamp hydrology, influencing long-term surface and groundwater regimes. This, in turn, can have a devastating impact on swamp ecology including many important habitats for protected flora and fauna. While the ecological value of THPSS is well understood, our current understanding of the hydrology of THPSS is limited. THPSS have been found to be dependent on groundwater, and subsequently the impact of modifying groundwater interactions can be significant. Recent research has concluded that a thorough understanding of the impact of longwall mining on the surface waterways and groundwater system is necessary before any remediation options to reduce loss of water into subsurface routes and minimise impact on water quality are considered.

Aims. To address this major knowledge gap, research into the fundamental hydrology of THPSS was undertaken. The purpose of this investigation was to understand the role of surface water and groundwater inputs and losses in maintaining swamp hydrology, providing a base level foundation from which the impacts of long-wall mining on ecology can be determined and guide future remediation efforts. To undertake on-ground research, multiple locations where data collection in peat swamps was being undertaken were utilised to form a foundation from which to expand swamp investigations and target site data gaps. Two swamps were selected for further detailed investigations, both located on the Woronora Plateau, approximately 80km south of Sydney, Australia. One site was within the Woronora Nature Reserve, where vegetation has been monitored regularly for 30+ years and basic climate monitoring for the past 5 years, and another swamp within the Sydney Metropolitan Catchment Management Area where climate monitoring, groundwater levels and swamp discharge has been monitored for the previous 5 years.  Extensive on-ground investigations were undertaken (and continue to be monitored) at these sites, providing fundamental scientific information for further assessment.

Methods. A series of groundbreaking on-ground investigations were undertaken to characterize the swamp hydrogeology and surface hydrology.  Detailed surveys of peat depth were initially undertaken using a push rod and RTK-GPS to determine digital elevation models (DEM) of surface topography and subsurface sandstone. Depth to underlying sandstone was found to be variable throughout the swamps (Figure 1). This survey guided the location and density of soil profiles and piezometer installations to characterize sediment characteristics, monitor water level fluctuations and assess water and soil chemistry.  A total of 17 piezometers were installed to bed rock, including logging soil stratigraphy and soil grab samples. Slotted 50mm diameter PVC was installed with a water level logger deployed near the bedrock. Soil samples were analysed for pH, EC, moisture, organic matter and a suite of analytes via ion chromatography. Hydraulic conductivity of the upper peat layer was also tested in-situ. Collected field data and site characterization surveys were combined to construct a three-dimensional numerical hydrological groundwater model to assist in determining the swamp water balance, hydrodynamics and to refine future sampling/analysis.

Figure 1: Example swamp depth survey and piezometer locations with conceptual groundwater flow paths

Figure 1: Example swamp depth survey and piezometer locations with conceptual groundwater flow paths

Findings. Findings include fundamental swamp hydrogeolgical characteristics, water balance summaries and analysis of degrees of freedom.  Swamp sediments were observed to vary both within swamps and between swamps. Sediment depths were found to range between 0.5 m to 2.6 m deep, with typical peat depths ranging between 30 cm – 100 cm of a dense organic layer in various stages of decomposition. The organic layer is underlain by grey sandy clay with clay content decreasing with depth (Figure 2). Sand and gravel was observed in the 10 cm to 30 cm range above bedrock.  Soil acidity was observed to be relatively uniform over depth with an average pH 5.7, however electrical conductivity and chloride decreased with depth; suggesting evapo-concentration of salts within the upper layers of the swamp. Soil moisture by weight and organic content were measured to decrease with depth, indicating decreasing porosity. Specific yield of swamp surface soils (0 m to 0.2 m) ranged between 15-20%, with deeper sediments (0.2 m to 0.4 m) approximately 10% greater.

Analysis of the water levels across the swamps, in conjunction with preliminary water balance modelling, indicates that despite the current data collection program, significant degrees of freedom remain unaccounted. Key factors such as transpiration, runoff, infiltration, interflow and groundwater losses are currently unknown and present seven sources of uncertainty within the water balance model. To reduce the uncertainty and close the water balance of peat swamps, further long term monitoring and site specific measurements are required. With the addition of soil core samples, soil hydraulic conductivity, long term water level data and further swamp geometry data, eight out of a total of nine water balance quantities will be known for the swamp, enabling increased reliability to assess the impacts of climate change, changes in land use, and undermining on long-term swamp ecology.  The findings from this study provide fundamental information that forms the basis for ongoing investigations critical for understanding peat swamp hydrology.

Figure 2: Typical swamp lithology

Figure 2: Typical swamp lithology

Acknowledgements. This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program.

Contact. William C Glamore and Duncan S Rayner, Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Australia (110 King St, Manly Vale, NSW 2093, Australia, Tel: +61/ 2 8071 9868. Email: w.glamore@wrl.unsw.edu.au ).

Conservation of an endangered swamp lizard

Key words:         Eulamprus leuraensis, fire impacts, disturbance ecology, habitat requirements, Scincidae

The Blue Mountains Water Skink is known from less than 60 isolated swamps in the Blue Mountains and Newnes Plateau of southeastern Australia (Fig 1). Understanding the species’ ecology, notably its vulnerability to threatening processes such as fire and hydrological disturbance, is essential if we are to retain viable populations of this endangered reptile.

Fig 1. Swamps containing Eulamprus leuraensis used in our baseline surveys (from Gorissen et al., 2015)

Fig 1. Swamps containing Eulamprus leuraensis used in our baseline surveys (from Gorissen et al., 2015)

Design: We surveyed swamps across the species’ known range to identify critical habitat requirements, and to examine responses both of habitat features (vegetation) and lizard populations to fire regimes and other anthropogenic disturbances. Our analyses of fire impacts included both detailed studies post-fire, and GIS-based analyses of correlations between lizard abundance and fire history.

Results to date: Blue Mountains Water Skinks appear to persist wherever suitable swamp habitat is maintained, although lizard numbers decline after frequent fires, hydrological disturbance or urbanization. However, the lizards (especially, adults) rarely venture out from the core swamp habitat into the surrounding woodland matrix. The “fast” life-history of this species (rapid growth, early maturation, high reproductive output) enables populations to recover from local disturbances, but very low vagility means that re-colonisation of a swamp after extirpation of a population is likely to be very slow (if it occurs at all).

Fig 2. Blue Mountains Water Skink within its swamp habitat (Photo: S. Dubey)

Fig 2. Blue Mountains Water Skink within its swamp habitat (Photo: S. Dubey)

Fig 3. Sarsha Gorissen checks a trap for lizards in a Newnes Plateau swamp (Photo: N. Belmer)

Fig 3. Sarsha Gorissen checks a trap for lizards in a Newnes Plateau swamp (Photo: N. Belmer)

Lessons learned and future directions: The suitability of a montane swamp for Blue Mountains Water Skinks can be readily assessed from soil-moisture levels and vegetation characteristics. Effective conservation of this endangered reptile species should focus on conserving habitat quality in swamps, rather than targeting the lizards themselves. If healthy swamps can be maintained, the lizards are unlikely to face extinction. Given high levels of genetic divergence among lizard populations (even from adjacent swamps), we need to maintain as many swamps as possible.

Stakeholders and Funding bodies: This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program.

Contact information: Prof Richard Shine, School of Life and Environmental Sciences, Heydon-Laurence Building A08, University of Sydney, NSW 2006 Australia. Phone: (61) 2-9351-3772; Email: rick.shine@sydney.edu.au

The spatial distribution and physical characteristics of Temperate Highland Peat Swamps on Sandstone (THPSS)

Key words: wetlands, upland swamp, geomorphology, mapping, Sydney Basin

Effective conservation and management of natural resources requires that we have an understanding of the spatial distribution and physical characteristics of the systems of concern. The results of the THPSS mapping project summarised here provide an essential physical (geomorphological) template atop which a range of other biophysical information on swamp structure, function and condition can be collated and interpreted.

Design. Using a 25 m Digital Elevation Modal (DEM) coupled with orthorectified aerial photography, the THPSS of the Sydney Basin were mapped in ArcGIS. Only valley-bottom swamps were mapped. Hanging swamps or hillslope drapes were excluded. In ArcGIS, the physical attributes of the swamps were attributed and measured. This included swamp area, elevation above sea level, swamp slope, catchment area, swamp and catchment elongation ratio, swamp length and distance to coast.

Figure 1: Regions in which THPSS occur in the Sydney Basin

Figure 1: Regions in which THPSS occur in the Sydney Basin

Results. Five regions of THPSS were mapped (Figure 1); Newnes (Figure 2), Blue Mountains (Figure 3), Budderoo (Figure 4), Woronora (Figure 5) and Gosford (Figure 6). Across these regions there is a total of 3208 individual THPSS. The combined area of these swamps is 101 km2 (10,100 ha) and the combined catchment areas that contain them cover 789 km2. They occur at a median distance of 57 km from the coast, but this is highly varied, ranging from 0.4 – 96 km.

The swamps occur in areas with an average annual rainfall of 1505 mm/year and average annual temperature is 15oC. They occur at a wide range of elevations. Those closer to the coast occur on elevations as low as 160 m ASL, and those further from the coast on plateau country can occur at elevations up to 1172 m ASL. The bulk of these systems occur at median elevations of 634 m ASL. The swamps are elongate in shape, having a median elongation ratio of 0.46. This makes the majority of these systems relatively long (median length is 216 m) and narrow. They occur in relatively elongate catchments with median elongation ratios of 0.61 and median catchment lengths of 488 m. Almost all these valleys terminate at their downstream ends at a valley constriction or bedrock step, making the valleys ‘funnel-shaped’.

Catchment areas draining into the swamps are, on average, 0.25 km2. This means these systems tend to occur in the very headwaters of most catchments in first or second order drainage lines. Each swamp is, on average, 31,537 m2 in area (3.1 ha). These swamps form on deceptively steep slopes. Median minimum swamp slope is 6.2%. The funnel-shaped valleys produce effective constrictions behind which alluvial materials and peat can accumulate, resulting in valley fills forming on relatively steep slopes.

 Stakeholders and Funding bodies. This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program. This project was also partly funded by an ARC Linkage Grant (LP130100120) awarded to A/Prof. Kirstie Fryirs and A/Prof. Grant Hose at Macquarie University. We thank Will Farebrother for working on this project. We thank the NSW Land and Property Information for the orthorectified aerial photographs that are used under a research-only license agreement.

Contact information. A/Prof. Kirstie Fryirs, Department of Environmental Sciences, Macquarie University, North Ryde, NSW 2109; +61298508367; kirstie.fryirs@mq.edu.au  A/Prof. Grant Hose, Department of Biological Sciences, Macquarie University, North Ryde, NSW 2109; +61298508367; grant.hose@mq.edu.au

Figure 2: THPSS of the Newnes region

Figure 2: THPSS of the Newnes region

Figure 3: THPSS of the Blue Mountains region

Figure 3: THPSS of the Blue Mountains region

Figure 4: THPSS of the Budderoo region

Figure 4: THPSS of the Budderoo region

Figure 5: THPSS of the Woronora region

Figure 5: THPSS of the Woronora region

Fig 6 - Gosford swamps map

Figure 6: THPSS of the Gosford region

Piccaninnie Ponds Conservation Park, South Australia

Mark Bachmann

Key words: wetland restoration, Ramsar, rising springs, drainage, hydrology

Piccaninnie Ponds Conservation Park is situated 30 km south east of Mt Gambier in South Australia. For 15-20 years after the park was proclaimed in 1969, there was considerable local interest in trying to address previous changes that had been made to the hydrology of the wetland system.

Although it was protected, reserved and supporting a diverse suite of habitats and range of resident threatened species, Piccaninnnie Ponds was far from intact from a hydrological perspective. Prior to European settlement, water that discharged from the karst, rising-spring wetlands in the system flowed eastward across the State border into the Glenelg River Estuary, in far South West Victoria.

This is how the system remained until 1906, when the first of several attempts to drain the wetlands of Piccaninnie Ponds directly to the sea occurred. What ensued was a turbulent 9 year period during which the fishermen successfully lobbied to have the creek re-directed to the Glenelg River in 1915; a step which was ultimately unpopular with affected landholders and resulted in an alternative flow path again being cut to the sea two years later in 1917. Subsequent ad hoc drainage and development of portions of the wetland system continued and by the time the Piccaninnie Ponds Conservatioon Park was proclaimed in 1969, a new main artificial outlet drained the ponds directly to the sea.

The first attempts at advocacy to restore environmental flows to the Glenelg River in the 1970s and 80s to counter this long-term drying trend in the Park were unsuccessful, until the concept was revisited and a series of steps undertaken, starting in 2001, to achieve hydrological restoration. These steps culminated in the following actions.

 Fig. 1 – Stage 1 weir and fishway under construction in 2006.

Fig. 1,  Stage 1 weir and fishway under construction in 2006.

Actions taken to correct hydrology

  1. 2006 – Stage 1 weir and fishway constructed at Piccaninnie Ponds (Figure 1) regulated outflows on the artificial outlet. This had the effect of increasing inundation in a small area immediately upstream of the structure, under the direct influence of the weir pool created by the new structure, as shown in Fig 2.
  2. 2013 – The stage 2 weir and fishway upgrade (Fig 3) resulted in the structure height being lifted to increase future management flexibility, including providing the future ability to completely block outflows, should the option of re-instating the original flow path one day become a reality.

The stage 2 upgrade was completed at the same time as providing a new flow path to physically reconnect the isolated eastern and western basins at Piccaninnie Ponds. These wetlands had been separated for several decades by a combination of lower water levels, sand drift and the impact of the Piccaninnie Ponds Road. An aerial photographic view of the new flow path is shown in Fig 4.

These works within the original Conservation Park, have occurred in in a complementary way with those that have occurred in the neighbouring, newly reserved area at Pick Swamp, each contributing to the wider vision for restoration of this wetland complex.

Fig. 2. Drained condition of habitat in 2006

Fig. 2a. Drained condition of habitat upstream of the Stage 1 weir (prior to construction  in 2006).

Fig. 3. The upstream inundation and habitat change caused by the stage 1 weir, 2012.

Fig. 2b. The upstream inundation and habitat change caused by the stage 1 weir, 2012.

Results to date.

  • Increase in quality and area of available habitat for native freshwater fish, including the nationally threatened Dwarf Galaxias (Galaxiellla pusilla)
  • Protection of hydrological processes that support a wide range of other threatened species, from a number of taxonomic groups
  • A positive trajectory of change in the distribution of wetland habitats in the vicinity of the works (increased aquatic habitat and reversal of a drying trend that was causing terrestrialisation of vegetation communities)
  • Re-establishment of connectivity between the western and eastern wetlands in the Park for the first time in several decades
Figure 4 – The lifted and redesigned stage 2 weir and fishway on the main artificial outlet at Piccaninnie Ponds – upon completion in 2013.

Fig. 3. The lifted and redesigned stage 2 weir and fishway on the main artificial outlet at Piccaninnie Ponds – upon completion in 2013.

Fig 5a. Piccaninnie

Fig. 4a. Before works – in January 2003

Figure 5 – TOP – Before works image: January 2003. BOTTOM – Post-construction/restoration image: January 2014.

Fig, 4b. After construction/restoration – in January 2014.

Future directions. The works and outcomes described here were delivered by staff working for the South Australian Department of Environment, Water and Natural Resources (DEWNR)

  • Ongoing management of the works and associated ecological monitoring in Piccaninnie Ponds Conservation Park is managed by DEWNR
  • Nature Glenelg Trust staff continue to provide specialist ecological advice and monitoring for the site when required by the site manager, DEWNR

Acknowledgements. The outcomes of the restoration project described can be attributed to a wide range of people who, in addition to the author (see current contact details below), worked at the South Australian Department of Environment, Water and Natural Resources during the period described. DEWNR project ecologists overseeing the works described here include Ben Taylor (stage 1 weir) and Steve Clarke (stage 2 weir and associated works).

The project was generously funded and supported by a range of different grants and programs administered by the South Australian Government, Australian Government and the South East Natural Resources Management Board.

Contact. Mark Bachmann. Nature Glenelg Trust, PO Box 2177, Mt Gambier, SA 5290 Australia; Tel +61 (0)8 8797 8181; Mob+61 (0) 421 97 8181; Email: mark.bachmann@natureglenelg.org.au Web| www.natureglenelg.org.au

See also:

Bradys Swamp EMR short summary

Long Swamp EMR short summary

Victorian Northern Plains Grasslands Protected Area Network: formation and future management

Nathan Wong

Key words: ecosystem decline, conservation planning, grassland restoration, threatened species

Building the network. Since the early 1990s Trust for Nature (Victoria) (TfN) in partnership with State and Federal government agencies and local land owners have been working to protect, restore and improve the condition and extent of Grasslands in the Victorian Riverina. This critically endangered ecosystem has been degraded, fragmented, and cleared over the past 200 years by a range of impacts largely associated with the exploitation of these areas for agricultural production. This use has resulted in the loss of over 95% of the original grassland extent in Victoria and the degradation of all remaining remnants.

The first major achievement of this program occurred in June 1997 when Trust for Nature acquired the 1277 ha ‘Davies’ property following many years of negotiations. This land was transferred to the Crown in April 1999 to form the Grassland section of what is now Terrick Terrick National Park. Since this initial acquisition a significant number of purchases have been added to the public estate with the support of both State and Federal National Reserve Systems Programs. These additions have resulted in Terrick Terrick National Park now covering over 3334ha (Table 1) and the establishment of Bael Bael Grasslands NCR during 2010 and 2011 which now covers 3119ha.

Running concurrently with this increase in the public estate has been a program to build and secure private land under conservation covenant as well as Trust for Nature establishing a number of reserves to build its private reserve network in the Victorian Riverina. These efforts have resulted in the addition of 2804ha owned by Trust for Nature, including Glassons Grassland Reserve (2001), Kinypanial (1999), Korrak Korrak (2001), Wanderers Plain (2009-2010) and 1036ha of private land protected under conservation covenant.

As a result of these efforts the area of grasslands within the Protected Area Network in the Victorian Riverine Plains has grown from virtually nothing in the mid-1990s, to in excess of 10,000ha and continues to expand.

OLYMPUS DIGITAL CAMERA

Fig 1. Very high quality Northern Plains Grasslands in Spring, note the inter-tussock spaces and diversity of flowering herbs (Photo: Nathan Wong).

Table 1. Acquisitions that have resulted in Terrick Terrick National Park, now covering over 3334ha.

Table 1

Current remnant condition. Whilst these grasslands are the best examples of the remaining ecosystem and protected under State and Federal government legislation, all of them have been degraded by past land-use. Therefore the need to not only protect but restore them is critical to the successful management of these systems in-perpetuity. Despite this past loss of a range of grazing-sensitive plant species many still persist in small isolated populations across the reserve network. Management of grazing, when it is applied, to ensure that continued losses do not occur whilst maintaining biodiversity values is one of the key aims of management. As a result of loss of quality, quantity and fragmentation of habitats, a range of important faunal species have also historically declined (Figs 2 & 3).

Need for management and restoration. There is great potential for management regimes to manipulate the composition of grasslands to enhance the likelihood of restoration success. Restoration of a range of grazing sensitive plant species which now either regionally extinct or remain in small isolated population will almost certainly require changes to grazing regimes, reintroduction of fire regimes and species reintroductions to ensure viable populations. Reintroducing faunal species will also require attention to connectivity and habitat availability issues in this context as many are dependent on the existence of large, interconnected territories e.g. Hooded Scaly-foot (Pygopus schraderi).

The Northern Plains Grasslands Protected Area Network: Strategic Operational Plan (SOP) is a landscape-scale strategic operational plan for the conservation management of the Northern Plains Grassland community within Victoria’s Protected Area Network, developed by the Northern Plains Technical Advisory Group in 2011. This Operational Plan now guides TfN and Parks Victoria in the implementation of an adaptive management plan for the landscape. This plan aims to establish and implement a restoration program across the public and private protected areas and is a marked shift from the previous management intent of maintenance of the system.

Fig 2. The area, particularly the Patho Plains and Lower Avoca, provide important habitat for the persistence of the Plains-wanderer (Photo David Baker-Gabb).

Fig 2. The northern plains grasslands, particularly the Patho Plains and Lower Avoca, provide important habitat for the persistence of the Plains-wanderer (Photo David Baker-Gabb).

Strategies for management and restoration. There are two main strategies that are being implemented. The first involves the extension of protected areas through a range of mechanisms; and the second involves active management to restore habitat quality and diversity to the extent possible.

Extent. Expansion of the current approach of reserve acquisition and covenanting that has been undertaken by the range of partners is likely to able to target and establish large areas (20,000+ ha) in the Lower Avoca and Patho Plains landscape. Both these areas are high priorities for Trust for Nature and form significant sections of the Trust for Nature’s Western Riverina Focal Landscape. The Patho Plains is significant as it is an Important Bird Area and a focus of Birdlife Australia to ensure the long term persistence of the Plains-wanderer (Pedionomus torquatus). The Lower Avoca also provides important habitat for the Plains-wanderer (Draft National Recovery Plan) and is one of the main population centres for Hooded Scaly-foot in Victoria.

Diversity. The increase of diversity and quality of these systems requires direct intervention in management as well as the introduction and establishment of the many rare and regionally extinct species from the system.

Plant species: Over the past decade, TfN and others have successfully trialled the reintroduction of a number of threatened and common plant species through hand sowing seed into grasslands. These species include: Hoary Sunray (Leucochrysum molle), Leafless Bluebush (Mairena aphylla), Rohlarch’s Bluebush (Maireana rohlarchii), Bladder Saltbush (Atriplex vesicaria), Plains Everlasting (Chrysocephalum sp. 1), Beauty Buttons (Leptorhynchos tetrachaetus), Small-flower Goodenia (Goodenia pusilliflora), Minnie Daisy (Minuria leptophylla) and a range of Wallaby species (Rytidosperma spp.) and Spear Grasses (Austrostipa spp.).

Animal species: Local habitat variability for a range of fauna has been achieved through the modification of grazing regimes and the introduction of burning regimes at a range of sites. This work aims to maximise niches and thus opportunities for a broad range of species.

Fig 3. Hooded Scaly-foot adult by Geoff BrownCOMP

Fig 3. Hooded Scaly-foot adult, a critically endangered legless lizard that occurs in the Northern Plains Grasslands, preferring habitat much like the Plains-wanderer. Photo: Geoff Brown.

Table 2.  Triggers required for various grazing and other management regimes to maintain appropriate intertussock spaces in Northern Plains Grasslands

Table2

Monitoring. The SOP includes a method for rapid assessment of habitat and functional composition of sites to support decision making and track habitat change over time. This is stratified by soil type as grazing and habitat values and floristic communities vary between soil types within the grassland mosaic. Triggers for action or management bounds have been set based on the structure of inter-tussock spaces on red soils. These have been established using the “Golf ball” method which calculates a golf ball score by randomly dropping 18 golf balls into a 1m x 1m quadrat and then establishing a count based on the visibility of the golf balls (>90% visible = 1, 90%-30% visible = 0.5, <30% visible = 0). For red soil grasslands the aim is to maintain the inter-tussock spacing within a golf ball range of 13-16 using the range of tools identified in Table 2. When a paddock reaches a golf ball score of 16 and it is being grazed, stock are to be removed. When the paddock reaches a score of 13 they are then to be reintroduced, within the bounds of the regime that is to be applied.

Additional to this there has also been collection of data in relation to the functional composition of sites with golf ball quadrats also assessed for the presence of a range of functional groups including Native C4 grasses, Native C3 Grasses, Exotic annual grasses, Exotic Perennial Grasses, Native forbs, Exotic Forbs, Native Shrubs, Moss cover, Other Crytptograms (i.e. Lichen, Algae, Liverworts), Bare Ground and Litter. At all these sites photos are also taken of each quadrat with and without golf balls and a landscape photo is also taken.

The capturing of these data and the region wide approach across both public and private areas will increase our knowledge of how to manage and restore these important sites as well as track progress of management actions and their effectiveness in providing protected areas for a range of threatened species.

Acknowledgements. A wide range of partners and individuals are involved in the protection of the Northern Plains Grassland and the development of the Northern Plains Strategic Operations Plan including Parks Victoria, Department of Environment, Land, Water & Planning (DELWP), La Trobe University, Charles Sturt University, Arthur Rylah Institute for Environmental Research, North Central Catchment Management Authority, Northern Plains Conservation Management Network, Elanus Consulting and Blue Devil Consulting.

Contact: Nathan Wong, Conservation Planning Advisor, Trust for Nature (Level 5, 379 Collins Street, Melbourne VIC 3000, Australia;Tel: +61 (0)3 8631 5888; Freecall: 1800 99 99 33; Mob 0458 965 329;Email: nathanw@tfn.org.au, www.trustfornature.org.au).

 

 

 

Defining reference communities for ecological restoration of Monjebup North Reserve in Gondwana Link

Justin Jonson

Key words: reconstruction; reference ecosystem; planning; ecosystem assemblage; monitoring

Introduction. Bush Heritage Australia’s (BHA) Monjebup North Reserve is a property that directly contributes to the conservation, restoration and connectivity objectives of Gondwana Link – one of Australia’s leading landscape scale restoration initiatives. Building on a solid history of revegetation projects implemented by collaborators from Greening Australia and individual practioners, the BHA management team initiated and funded a $40K Ecological Restoration Planning Project for 400 hectares of marginal farmland in need of restoration.

The specific aim of the Monjebup North Ecological Restoration Project was to 1) plan and 2) implement a ‘five star’ ecological restoration project as defined by the Gondwana Link Restoration Standards. Overarching goals included the re-establishment of vegetation assemblages consistent with the surrounding mosaic of plant communities, with a specific focus on local fauna and the restoration of habitat conditions to support their populations.

Figure 1: Map showing GPS locations of soil auger sampling locations.

Figure 1: Map showing GPS locations of soil auger sampling locations.

Planning and identification of reference communities for restoration of cleared land. The Monjebup North Ecological Restoration Project began with a third party consultancy contract to develop the Monjebup North Ecological Restoration Plan. This work began with the collection of detailed field data, including 120 soil survey pits collected to define the extent and boundaries between different soil-landform units occurring on the site (Fig.1). In the absence of previously defined and/or published information on local plant communities, an additional vegetation survey and report, The Vegetation of Monjebup North, was developed, which included 36 vegetation survey sites widely distributed across the surrounding vegetation (Fig.2). A total of 10 primary vegetation associations were defined within remnant vegetation on and around the site from this work (Fig.3). Additional soil survey pits were established within these defined plant communities to develop relationships between observed vegetation associations and soil-landform units. Cross referencing this information to the 400 hectare area of cleared land resulted in the delineation of seven core reference communities to guide the restoration project. These restoration communities ranged from Banksia media and Eucalyptus pluricaulis Mallee Scrub associations on spongelitic clay soils, to Eucalyptus occidentalis (Yate) Swamp Woodland associations located in low-lying areas where perched ephemeral swamps exist.

Figure 2: Map showing GPS locations of flora survey sampling sites.

Figure 2: Map showing GPS locations of flora survey sampling sites.

Figure 3: Output map of dominant vegetation associations at Monjebup North Reserve.

Figure 3: Output map of dominant vegetation associations at Monjebup North Reserve.

Figure 4: Mosaic of plant communities replanted at Monjebup North in 2012 using direct seeding and hand planted seedlings. A tractor fitted with GPS unit enables real time seeding passes, as shown on the map.

Figure 4: Mosaic of plant communities replanted at Monjebup North in 2012 using direct seeding and hand planted seedlings. A tractor fitted with GPS unit enables real time seeding passes, as shown on the map.

Figure 5: Mosaic of plant communities replanted at Monjebup North in 2013 using direct seeding and hand planted seedlings. A tractor fitted with GPS unit enables real time seeding passes, as shown on the map.

Figure 5: Mosaic of plant communities replanted at Monjebup North in 2013 using direct seeding and hand planted seedlings. A tractor fitted with GPS unit enables real time seeding passes, as shown on the map.

Seed sourcing. Seed from approximately 119 species were collected on and around the site for the restoration works. Seed collections for some species were collected from a number of geographically separate sub-populations, however these were never located further than 10 kilometers from site. Collections were made from at least 20 individuals for each species, and preference was made in collecting from populations which had 200+ individuals.

The primary on-ground works were initiated across four years from 2012 to 2015, starting with a 100 ha project area in 2012 (Fig.4), and a 140 ha area in the following year (Fig.5), both by Threshold Environmental Pty Ltd. A combination of direct seeding and hand planted seedlings treatments were employed, where seed mixes were developed to achieve the bulk of plant recruitment across each of the soil-land form units, and nursery grown seedlings were planted by hand for species found to be difficult to establish from direct seeding or for which stocking densities were to be more closely controlled. This work involved 13 communities and 148 species.

A number of innovative operational treatments were employed. These included grading 5 kilometers of contour banks and spreading chipped vegetation and seed pods, and 180 in situ burning patches where branch and seed material from fire-responsive serotinous species were piled and burned (Fig.6 before, Fig.7 after). Seedlings for rare, high nectar producing plant species were also planted in 203 discrete ‘node’ configurations. Habitat debris piles made of on-site stone and large branch materials were also constructed at 16 locations across the 2012 project areas.

Fig.6 In situ burning of serotinous branch and seed material

Figure 7: Photo of Dryandra nervosa juvenile plants establishing from one of the in situ burn pile locations. Other species used for this technique included Dryandra cirsioides, Dryandra drummondii, Hakea pandanicarpa, Isopogon buxifolius, and Hakea corymbosa.

Figure 7: Photo of Dryandra nervosa juvenile plants establishing from one of the in situ burn pile locations. Other species used for this technique included Dryandra cirsioides, Dryandra drummondii, Hakea pandanicarpa, Isopogon buxifolius, and Hakea corymbosa.

Monitoring. Monitoring plots were established to evaluate the direct seeded revegetation, as presented in the Project Planting and Monitoring Report 2012-2013. Fauna monitoring has also been undertaken by BHA using pit fall traps, LFA soil records, and bird minute surveys.

Results to date. Monitoring collected from post establishment plots in from the 2012 and 2013 areas (2 years after seeding) showed initial establishment of 2.4 million trees and shrubs from the direct seeding (Fig.8 and Fig.9). Results of faunal monitoring are yet to be reported, but monitoring at the site for vegetation and faunal is ongoing.

Figure 8: Graphic representation of monitoring results from 2012 and 2013 operational programs showing scaled up plant counts across the plant community systems targeted for reconstruction.

Figure 8: Graphic representation of monitoring results from 2012 and 2013 operational programs showing scaled up plant counts across the plant community systems targeted for reconstruction.

Figure 9: Photo showing 3 year old establishment and growth of a Banksia media/Eucalyptus falcata Mallee shrub plant community with granitic soil influence from the 2012 Monjebup North restoration project.

Figure 9: Photo showing 3 year old establishment and growth of a Banksia media/Eucalyptus falcata Mallee shrub plant community with granitic soil influence from the 2012 Monjebup North restoration project.

Lessons learned and future directions. The decision to develop a restoration plan in advance of undertaking any on-ground works was a key component contributing to the success of the project to date. Sufficient lead time for contracted restoration practioners to prepare (>12 months) was also a key contributor to the success of the delivery. Direct collaboration with seed collectors with extensive local knowledge also greatly benefited project inputs and outcomes.

Stakeholders and Funding bodies. Major funding for the project was provided by Southcoast Natural Resource Management Inc., via the Federal Government’s National Landcare Program and the Biodiversity Fund. Of note is also Bush Heritage Australia’s significant investment in the initial purchase of the property, without which the project would not have been possible.

Contact information. Justin Jonson, Managing Director, Threshold Environmental, PO BOX 1124, ALBANY WA 6330 +61 427 190 465; jjonson@thresholdenvironmental.com.au

See also EMR summary Peniup

 Watch video: Justin Jonson 2014 AABR presentation

Subtropical rainforest restoration at the Rous Water Rainforest Reserve, Rocky Creek Dam, 1983 – 2016

Key words: Lowland subtropical rainforest, ecosystem reconstruction, drinking water catchment, continual improvement process.

Introduction. Rous Water is actively engaged in ecosystem reconstruction within the drinking water catchment areas it manages on behalf of the community. The aim of these activities is to improve the functioning of essential natural processes that sustain water quality. The methodology used for rainforest restoration by Rous Water has evolved over time through an ‘adaptive management’ process at Rocky Creek Dam. This adaptive management approach has demonstrated that effective large scale sub-tropical regeneration at Rocky Creek Dam is achieved through complete removal of competing plants. The technique has become known as the Woodford Method and is now being applied at other Rous Water restoration sites.

The Rous Water Rainforest Reserve at Rocky Creek Dam is set in the northern headwaters of the Richmond River catchment, on the southern rim of the Tweed shield volcano. Basalt flows from the volcano have produced nutrient rich Red Ferrosol that supported diverse sub-tropical rainforest ecosystems across the region, until the rainforest was largely cleared for agriculture in the late 19th century. The Rocky Creek Dam site is adjacent to the Big Scrub Flora Reserve, the largest remaining remnant subtropical rainforest in the region. This reserve acts as a reference site for the restoration project (Fig 1).

Figure 1. Detail of the regeneration areas at Rocky Creek Dam, showing the areas treated and the year of the initial works

Figure 1. Detail of the regeneration areas at Rocky Creek Dam, showing the areas treated and the year of the initial works

Clearing of land in the vicinity of Rocky Creek Dam by early settlers commenced in the 1890s, with the cleared lands used for the establishment of dairy farms and a sawmill. In 1949, following acquisition of the site by Rous County Council (now Rous Water) for the construction of a water supply dam, this former farmland had reverted to weedy regrowth characterised by a mosaic of native/exotic grass, Lantana (Lantana camara) and Camphor Laurel (Cinnamomum camphora) which supressed any expansion or recovery of scattered rainforest remnants. Transformation of the site commenced in 1983 when Rous Water became actively engaged in ecosystem recovery by systematically removing weeds that suppressed rainforest regeneration, a practice that continues today.

Rainforest restoration methods. The practices and management tools used in rainforest restoration at the site have been previously described by Woodford (2000) and Sanger et al. (2008). The work method typically involves the systematic poisoning and slashing of weeds to promote recruitment of rainforest plants from the soil seed bank and then to facilitate the growth of suppressed rainforest plants, providing a structural framework for further seed dispersal by wind and, particularly, flying frugivores and thus further colonisation by later phase rainforest trees.

Since 1983, an area of approximately 70 ha has been progressively treated in 1-2 ha blocks using this methodology (refer Fig 1), with progressively diminishing amounts of follow-up treatment needing to be conducted in the treated areas over subsequent years to secure successional progression of the rainforest species.

Use of this method means that, due to recruitment from the seed bank and the use of stags (from dead camphor laurel) as perches for seed dispersing birds, very limited planting has been required on the site. This has preserved the genetic integrity of the Big Scrub in this location.

Results. A total of approximately 70 hectares of weed dominated regrowth has been treated at the Rous Water Rainforest Reserve since commencement in 1983 (Figure 1). This is approximately 35 ha since the report previously published in 2000 and represents approximately 30 % of the Rous Water property at Rocky Creek Dam.

This progressive treatment of compartments of weedy regrowth at Rocky Creek Dam has continued to lead to rapid canopy closure by shorter lived pioneer and early secondary tree species, with a gradual progression to higher proportions of later secondary and primary species with increasing time since treatment. All tree species that are listed as occurring in the reference site are not only now present in the restoration area, but informal observations suggest that most, if not all, are increasing in abundance over time (Figs 2-6)

Figure 2. Treated regrowth at the Rous Water Rainforest Reserve, Rocky Creek Dam After 1 year (foreground)

Figure 2. Typical regeneration of rainforest species 1 year after Lantana removal at the Rous Water Rainforest Reserve, Rocky Creek Dam (foreground).

Figure 3. Same photopoint after 6 years

Figure 3. Typical recovery after 6 years

Figure 4. Same photopoint after 12 years

Figure 4. Typical recovery after 12 years

Figure 5. Same scenario after 20 years

Figure 5. typical recovery after 20 years

Figure 6. After 30 years

Figure 6. Typical recovery after 30 years

The structure of the older treated regrowth areas sites appears to be converging on rainforest conditions, as noted by Kanowski & Catterall (2007). Thackway & Specht (2015) depict how 25 ha of systematically treated compartments that were covered almost entirely with lantana are progressing back towards the original Lowland Subtropical Rainforest’s composition, structure and ecological function (Fig 7). Overall the vegetation status in this area was assessed at between 85% and 90% of its pre-clearing status.

This process is, at its oldest 33 years old and in some locations much younger. So it is clear that the development of the subtropical vegetation still has many decades, possibly centuries, to go, before it approaches the composition, structural and habitat characteristics of a primary forest. Notwithstanding the large areas of natural regrowth that are yet to be worked, it is evident that a large proportion of the assisted regeneration areas progressively worked by Rous over the past 33 years now requires only a low level of ongoing maintenance. This shows that these sites are maturing over time and have largely reached a self-organising state, and in the fullness of time will achieve a high degree of similarity to the reference state.

Fig 7, Thackway fig rocky creek dam1

Figure 7. Assessment of change in indicators of vegetation condition in a 25 ha area. This depicts the degree of recoveery of Lowland Subtropical Rainforest found at Rocky Creek Dam, Big Scrub, NSW against a pre-clearing reference. (Graph reproduced with permission. The method used to generate the graph is described in Thackway, R. and Specht, A., (2015). Synthesising the effects of land use on natural and managed landscapes. Science of the Total Environment. 526:136–152 doi:10.1016/j.scitotenv.2015.04.070. ) Condition indices for transition Phase 4 were derived from prior reports including Sanger et al. 2008 and Woodford 2000. Metadata can be viewed at http://portal.tern.org.au/big-scrub-rocky-queensland-brisbane/16908 .

Lessons learned. Using this method of harnessing the natural resilience processes of the rainforest, we have been able to progress the recovery of an important water catchment area, restoring very high biodiversity conservation values in a landscape where rainforest was, and remains, in serious decline., The ability of the high resilience sites at Rocky Creek Dam to respond to the Woodford Method is clearly demonstrated, but there is ample evidence that application of this and similar resilience-based rainforest restoration methods can harnessed resilience at other sites in the Big Scrub that are at greater distances from remnants.

Figure 8. Distribution of management intensity classes across the Rous Water Rainforest Reserve at Rocky Creek Dam.

Figure 8. Distribution of management intensity classes across the Rous Water Rainforest Reserve at Rocky Creek Dam. (Legend for this map is in Appendix 1)

Current work and future directions. Work continues at the site and management is supportive of-site evaluation to assess the extent to which the treated areas are undergoing successional development using a range of available assessment tools.

To assist future planning, and in order to address the issue of how to best estimate and plan for restoration works and associated costs, Rous Water has adapted the methodology developed on the Tweed-Byron Bush Futures Project, where each restoration site/area was assigned a Management Intensity Class (MIC) based on a generalised assessment of site condition, weed composition and cover and other management requirements. (Fig 8) The MIC describes the frequency of restoration work required to restore the site to a minimal maintenance level and how many years this would take to achieve. The MIC aims to describe the extent of management intervention necessary to restore the site to a minimal maintenance level. For this analysis this equates to the establishment of a self sustaining sub-tropical rainforest buffer zone. Each management intensity class is associated with a particular restoration trajectory/cost per hectare, based on visitation frequency by a standard 3 person team and expressed in terms of number of visits required to control / manage weeds. Appendix 1 below shows details of the MIC classification, showing for each class, relevant site criteria, and the estimated level of bush regeneration resources required to bring each class to a low maintenance level.

Contact: Anthony Acret, Catchment Assets Manager,  Rous Water. Tel: +61 (0) 2 6623 3800, Email: anthony.acret@rouswater.nsw.gov.au

Appendix 1. Legend for Management intensity classes used in Fig 8. (From Tweed-Byron Bush Futures)

Appendix 1. Legend for Management intensity classes used in Fig 8.