True restoration of highly disrupted native ecosystems is universally difficult, and has not been achieved on waste rock dumps at a rock phosphate mine in the resource-limited rangeland environment of semiarid Queensland, Australia. Thirteen years after rehabilitation, there is general correspondence, but some temporal variation, in tree and shrub species richness between rehabilitated and analogue native vegetation sites. Large differences in the composition and extent of ground cover vegetation were associated with dominance of most sites by an introduced perennial pasture grass species and by periodic drought. Complete reinstatement of native ecosystems is shown to be inconsistent with the physical constraints of waste rock dumps, the erratic climate, the previous history of extensive grazing and a lack of effective rehabilitation planning. Revised goals of strict landscape stability and broad biodiversity attributes, based on those of relevant native ecosystem analogues, are proposed to enable the identification of appropriate native and novel ecosystem targets for the modified landscapes. Novel ecosystems combining tree and shrub components of the native vegetation, and ground cover (including introduced grasses) could provide the most effective targets for mined land rehabilitation in a semi-arid environment. Principles are suggested for the selection of vegetation targets for the rehabilitation of mine waste rock dumps, considering the new lithologies and landforms and the occurrence of a dominant introduced grass species. These principles should be applicable widely, but especially in resource-limited environments. (C) 2015 Elsevier B.V. All rights reserved.

The Central Queensland Mine Rehabilitation Group (CQMRG) has hosted mine site rehabilitation inspections combined with technical workshops for more than 20 years. It was recognised at CQMRG's anniversary meeting in April 2013 that the vast body of knowledge held by rehabilitation and closure planning practitioners was being lost as senior rehabilitation experts retire from the industry. It was noted that even more knowledge could be readily lost unless a knowledge management platform was developed to capture, store and enable retrieval of this information. This loss of knowledge results in a significant cost to industry. This project was therefore undertaken to review tools which have the capability to gather the less formal knowledge as well as to make links to existing resources and bibliographic material. This scoping study evaluated eight alternative knowledge management systems to provide guidance on the best method of providing the industry with an up-to-date, good practice, knowledge management system for rehabilitation and closure practices, with capability for information sharing via a portal and discussion forum. This project provides guidance for a larger project which will implement the knowledge management system to meet the requirements of the CQMRG and be transferrable to other regions if applicable. It will also provide the opportunity to identify missing links between existing tools and their application. That is, users may not be aware of how these existing tools can be used to assist with mine rehabilitation planning and implementation and the development of a new platform will help to create those linkages. The outcomes of this project are directed toward providing access to a live repository of rehabilitation practice information which is Central Queensland coal mine-specific, namely: highlighting best practice activities, results of trials and innovative practices; updated legislative requirements; links to practices elsewhere; and informal anecdotal information relevant to particular sites which may be of assistance in the development of rehabilitation of new areas. Solutions to the rehabilitation of challenging spoils/soils will also be provided. The project will also develop a process which can be applied more broadly within the mining sector to other regions and other commodities. Providing a platform for uploading information and holding discussion forums which can be managed by a regional practitioner network enables the new system to be kept alive, driven by users and information needs as they evolve over time. Similar internet-based platforms exist and are managed successfully. The preferred knowledge management system will capture the less formal and more difficult to access knowledge from rehabilitation and mine closure practitioners and stakeholders through the CQMRG and other contributors. It will also provide direct links, and greater accessibility, to more formal sources of knowledge with anticipated cost savings to the industry and improved rehabilitation practices with successful transitioning to closure and post-mining land use.

The rehabilitation of land disturbed by mining is a statutory requirement in Australia. Effective rehabilitation is essential for maintaining a 'social licence to operate'. It reduces risk for mining companies by minimising residual risk payments, reducing administrative uncertainties at closure and creating an agreed transition to post-mining landscapes.

This study depicts broad-scale revegetation patterns following sand mining on North Stradbroke Island, south-eastern Queensland, Australia.

A requisite corollary of mineral sand mining on North Stradbroake Island (Queensland (Qld), Australia) has been the progressive rehabilitation of post-mined lands for the revegetation of native subtropical Eucalypt communities. Since 2005, rigorous environmental monitoring has been undertaken to verify the annual development of post-rehabilitated sites. From these longterm analyses, a chronosequence of land revegetation (ranging from three to 26 years postrehabilitation) was developed to examine the rehabilitation trajectories of various post-mined sites in relation to proximal undisturbed locations. Here, we identifi ed that some sites may be deviating from the intended natural analogues as evidenced by the opportunistic colonisation and otherwise ‘invasive’ behaviour of a regionally native species (Black Sheoak − Allocasuarina littoralis), which appear to be displacing the intended Eucalypt varieties. Although it is recognised that the broader data trends correspond to distinct periods of adaptive modifi cations to the implementation of rehabilitation (ie pre- and post-1995), this analysis focuses on further identifying potential above- and belowground feedback mechanisms underlying these divergent ecological outcomes.

Mine ecological monitoring schemes are often conducted only to address compliance and in some cases do not have the suffi cient statistical power or understanding of ecological systems to assess, quantitatively, the meeting of rehabilitation targets or mine impacts. Monitoring schemes for rehabilitation commonly rely on analogue sites or premining baselines (reference sites) to assess whether rehabilitation sites are ecologically similar and thus successfully rehabilitated. In the case of monitoring for mine impacts, if the impacted sites diverge from reference data, the site is considered to be impacted. Fundamental to any monitoring scheme is testing the sampling design to ensure that it can detect these differences if they are present through adequate sample sizes (ie statistical power). However, a good understanding of the ecological system is required to ensure that differences detected are ecologically signifi cant. Modelling ecosystem properties can provide a quantitative understanding of how ecosystems change over time and space, in response to natural environmental variations and thus aid in determining signifi cant ecological differences. Furthermore, modelling methods can be used to predict future ecosystem states. Within the ecological literature, guidelines for robust statistical monitoring designs and modelling methods exist but are not routinely being used in the mining industry. This paper uses simple examples to discuss: problems with current compliance monitoring methods; importance of robust statistical techniques; and how modelling can assist rehabilitation assessment and guide monitoring schemes. The aim of this paper is to describe general monitoring and modelling methods that could be potentially used for mine site monitoring and closure assessment. These methods are often considered by mining companies as an extra expense that provide little practical benefi t, and the domain of academia; however, engaging these methods may be more cost-effective in the long-run than conducting untargeted monitoring schemes that give no confi dence to regulators on whether rehabilitation criteria have been met. Furthermore, monitoring programs in mining contexts provide a good opportunity to better understand long-term ecological patterns and test the application of more rigorous modelling approaches as the life of many mines tends to be greater than ten years.

The Ernest Henry Mine in north west Queensland, Australia, is required to return disturbed land to native grassland and has been undertaking extensive revegetation of waste rock dumps since 2002. To ascertain the trajectories for revegetation success of these rehabilitated native grasslands, annual vegetation monitoring of both rehabilitation sites and selected reference areas has been undertaken since 2007. Long-term monitoring efforts have included assessments of vegetation composition, ecological structure and function at four rehabilitation areas (1–7 years post-rehabilitation) and proximal reference sites within surrounding grazed and ungrazed agro-ecosystems, undisturbed by mining. Our findings demonstrated that the oldest rehabilitated sites had similar species composition and functional elements to selected reference sites, although plant cover and biomass (particularly of native grasses) was lower than both grazed and ungrazed reference areas. The youngest sites had little established vegetation, however species richness was similar to the reference sites and functional life forms were present despite being in very low abundance. It is suggested that future monitoring events and informed management inputs (which consider local climatic conditions and soil fertility factors) could contribute to the development of a stable and sustainable native grassland thus achieving the desired end land use on these post-industrial landscapes.

Mine site rehabilitation generally includes the re-shaping of overburden to create a final landform, manipulation of substrates and subsequent revegetation. Due to the wide range of environmental variables that influence rehabilitation progression, having clearly-stated final land-use goals and ongoing significant contributions to the planning process, from prefeasibility through to mine closure, is essential for achieving stable landforms and sustainable rehabilitated communities. Two examples of rehabilitation processes in the phosphate rich region of North West Queensland are used to illustrate some of the possible benefits of early planning and communication of rehabilitation requirements.Approximately 160 km south of Mount Isa, Incitec Pivot Limited operates a 35 year old open cut mine at Phosphate Hill. Monitoring of rehabilitation areas and selected analogue sites is undertaken annually, but the initial landform design, substrate management and species selection has created a difficult environment for revegetated areas to successfully establish. Constant management input (such as weed management, erosion control, supplementary seeding, etc) will, therefore, be required over a long time frame.The second example uses exploratory drilling and historic costean pits at Legend International Holding’s Paradise South site, 135 km north of Mount Isa, to determine the success of natural vegetation colonisation on waste rock and compacted soils, and the effects of cattle grazing on recolonisation. This information can be used by planners of the mine life to inform possible endland use decisions and proposed completion criteria.In a semi-arid environment such as North West Queensland, the creation of a post-mine landscape suitable for nature conservation and/or grazing can be an arduous task. The input from environmental personnel at all stages of the mining process will positively impact upon the quality of the resulting rehabilitation and ensure undesirable legacy issues are minimised.

A large body of information on all aspects of coal mine rehabilitation across Australia has accumulated since large scale operations began several decades ago. However, the information contained in company sponsored reports, conference proceedings and journal articles is stored in numerous locations, is often fragmented and not readily accessible. With high turnover of mine environmental staff, loss of key individuals who maintain some continuity of knowledge, and the increasing proportions of graduates with less experience and site history, there is a high risk that staff new to the industry, sector or a particular site may not even be aware that work in a certain area has already been conducted. This will continue to lead to some obvious problems, including unnecessary repetition of work, initiation of ill-informed avenues of investigation, and an inability to learn from past mistakes that can result in impediments to opportunities for improvements in mine rehabilitation methodologies.

Phaius australis F. Muell. (swamp orchid) is a large, endangered terrestrial orchid typically associated with coastal swamps in north-eastern Australia, including North Stradbroke Island. Populations of P. australis were studied at three locations along the toe of a steep sand escarpment adjoining Eighteen Mile Swamp, where recent water table elevations had varied, and on a flat peaty substrate at a freshwater stream outflow into the swamp. Orchids occurred on a strip usually less than 4m wide associated with water table depths between 0.05 and 0.5m. Leaves were up to 1.5m long and flowering stems up to 2m tall. Larger plants were more likely to produce an inflorescence but pseudobulbs remaining from previous seasons did not appear to act as major reserves for inflorescence production by the current season shoot. Orchid plant size was not related to tree canopy cover, ground cover or proximity to the swamp edge. Changes in water table elevation associated with sand mining operations were not reflected in detectable differences in mature shoot heights or pseudobulb numbers. The frequency of inflorescence production was higher in populations with rising or high water tables. Small plants were absent from the sector of the escarpment that experienced an increase in water table elevation of about 0.5m during the study. It was concluded that the transitory elevation of ground water levels due to sand mining did not have a deleterious or lasting effect on the vigour of orchid plants or the structure of orchid populations. Browsing, probably by a native herbivore, of up to 90 per cent of inflorescences in the areas of greatest flowering frequency may represent a major issue for seed production in this species.