R estoring the Botanical. Richness of the Jarrah Forest. After Bauxite Mining. in South-Western Australia ALCOA WORLD ALUMINA AUSTRALIA

Transcription

1 R estoring the Botanical Richness of the Jarrah Forest After Bauxite Mining in South-Western Australia ALCOA WORLD ALUMINA AUSTRALIA

2 CORPORATE OFFICE Alcoa World Alumina Australia Cnr Davy and Marmion Streets Booragoon Western Australia Phone: (61 8) Fax: (61 8) POSTAL Alcoa World Alumina Australia PO Box 252 Applecross WA Printed November 2003

3 RESTORING THE BOTANICAL RICHNESS OF THE JARRAH FOREST AFTER BAUXITE MINING IN SOUTH-WESTERN AUSTRALIA SUMMARY An innovative improvement program spanning two decades has achieved a significant milestone for Alcoa s mine rehabilitation - re-establishment of young jarrah forests with plant species richness equal to the surrounding native forest. Mining is a transient land use. Alcoa s aim after bauxite mining in the jarrah forest of south-western Australia, is to re-establish all the pre-existing land uses of the forest. These uses include conservation, timber production, water production and recreation. Re-establishing a jarrah forest on the mined areas, as similar to the original forest as possible, is the best way to achieve all of these goals. The jarrah forest is also renowned for its diverse flora, being one of the most plant species rich forests in the world, outside of tropical rainforests. Hence restoring botanical richness in the new forests on mined areas is a critical objective for Alcoa. Efforts to improve plant richness in rehabilitated mines commenced in the mid 1970 s, when the first studies were made of the seed content of forest soils. Practices to preserve seed viability in the soil and to separate the seed-rich topsoil from the remaining overburden were soon developed. In the late 80 s we started to regularly monitor botanical richness in rehabilitated mine areas. In 1990 we recorded in our newly rehabilitated areas 65% of the number of plant species compared with adjacent native forest - and this was using best practice rehabilitation methods of the time. Since then, we have undertaken a ten year research and development program to further improve rehabilitation practices. An important part of our strategy was setting clear and measurable objectives that all levels in the company actively endorsed. The program started with 5 year improvement milestones. Our first milestone was to achieve 80% of forest species richness. When this was achieved, we set a new milestone for 2000: The average number of indigenous plant species in 15 month old rehabilitation is 100% of the number found in representative jarrah forest sites We developed and implemented many innovative practices and technologies in the areas of seed treatment, seed application, topsoil handling, mine planning, and native plant propagation. Our own research team, along with collaborative projects with external academic staff and students, developed the science. Commitment and dedication from our technical and operational staff, supervisors and management were necessary for this to succeed. We have steadily increased botanical richness in our rehabilitated mines and in 2000, at our two operating mines at Huntly and Willowdale, we achieved an average of 100.7% for all the rehabilitated areas. Part of the Huntly mine in The South Dandalup dam is in the background. The same view in The mining and infrasrtucture has been successfully rehabilitated. 1

4 MINING AND REHABILITATION PROCESS Sequence of photographs showing various stages of the mining and rehabilitation process from the removal of timber from the forest prior to mining though to a one year old rehabilitated area. All useful products including sawlogs, fence posts and firewood are removed before mining. The topsoil and overburden are stripped off using scrapers. These two layers will be returned to a rehabilitated pit in the same order. Wherever possible the topsoil is returned immediately to a newly rehabilitated area. This direct return is the best way to restore the natural seeds, the important microbes and the fertility of the soil. The bauxite layer is usually 4 to 5 meters thick and is mined using large excavators and haul trucks. 2

5 The edges of the mined pit are pushed down and smoothed out to produce a smooth rolling topography. Topsoil and overburden are returned as two distinct layers either as direct return from a new mine pit wherever possible or from a stockpile. The pit is ripped on contour using a winged tine to a depth of 1.5 m. The seed is applied onto the freshly ripped ground by the air seeder mounted on the bulldozer. Deep ripping breaks up the compacted ground and the ripping mounds stop soil erosion. This is a one year old rehabilitated area. Logs and rocks are returned to provide shelter and nesting sites for animals. 3

6 DESCRIPTION OF ALCOA S MINING OPERATIONS Alcoa World Alumina Australia operates two bauxite mines at Willowdale and Huntly in the Darling Range of southwestern Western Australia, km south of Perth. A third mine at Jarrahdale operated from 1963 to 1998 and has now been completely decommissioned and rehabilitated. The Huntly mine is the largest bauxite producer in the world. The bauxite from the two mines is processed to alumina at three refineries at Kwinana, Pinjarra and Wagerup. The alumina is then shipped interstate or overseas for smelting to produce aluminium. The bauxite ore is relatively shallow, averaging 4 to 5 m deep and is located usually less than one metre below the soil surface. The mine pits range in size from one to tens of hectares. Alcoa has been rehabilitating its bauxite mines since 1966 and currently approximately 550 ha are mined and rehabilitated annually. All areas cleared for mining and infrastructure are rehabilitated. The technology of rehabilitation has seen continuous improvement over the years from plantations of exotic pine trees to a sophisticated state-of-the-art rehabilitation program. After timber harvest, the mining sequence involves: clearing the remaining vegetation, removing the soil, blasting the cemented bauxite layer or ripping it with a bulldozer, removing and crushing the bauxite before transporting it to the refineries. The rehabilitation process starts with shaping the mine pit to produce a landscape that blends with the surrounding forest. Soil is returned to the mine pit and the pit is ripped using a bulldozer pulling a winged tine - ripping breaks up compacted ground which reduces the risk of erosion and improves tree growth. Seeds of local plants are spread throughout the rehabilitated mine pit. Planting of nursery grown plants is also carried out for species where seed is not a viable method of establishment - this is a new initiative that will be described later. A fertiliser mix is then applied in late winter or early spring using a helicopter. Perth Kwinana Jarrahdale Map Area Mandurah Pinjarra Huntly Dwellingup Alcoa s operations in Western Australia. Huntly and Willowdale are our two active mines. Mining finished at Jarrahdale in 1998 and the mine was completely decommissioned and rehabilitated by Wagerup Willowdale Boddington Bunbury Collie MAP KEY Busselton Mineral Lease 1sa Jarrah Forest Mined & Rehabilitated Jarrah Forest Principal Mineralised Area Manjimup Karri / Jarrah Forest Pemberton km 4

7 ENVIRONMENTAL ISSUES Mining takes place in the jarrah (Eucalyptus marginata) forest, within a one to one-and-a-half hour drive of Perth. The mines are entirely within Perth and regional water supply catchments. The jarrah forest has high conservation value, is the basis of a major sawmilling industry and is widely used for recreation pursuits. The forest is managed by State Government authorities for these multiple uses. The proximity to Perth and the uniqueness of the jarrah forest present an enormous challenge in terms of environmental management and rehabilitation. The main potential environmental issues are water catchment protection, the spread of Phytophthora dieback disease, loss of timber production, loss of flora and fauna diversity and impacts on our neighbours and local communities such as noise, dust and access to forest. We manage all of these issues intensively and in a systematic manner. Both mines recently received ISO certification for their environmental management systems. Restoring the botanical richness is seen as an important component of re-establishing a jarrah forest. In 1990 our botanical richness measure of the rehabilitated minepits was 65% compared with adjacent native forest - this was achieved using best practice methods. Achieving our ultimate goal of 100% was a major challenge. To be successful we would have to markedly improve the current best practices and develop innovative practices to take our rehabilitation program to a new level of commitment and sophistication. Jarrah forest near the Huntly mine. RESTORING THE BOTANICAL RICHNESS OF THE JARRAH FOREST The current rehabilitation objective is to re-establish a functional jarrah forest ecosystem that will fulfil the forest land uses. These include conservation, timber production, water catchment and recreation. To reinstate the conservation value and recreation value it is necessary to re-establish the biodiversity of the jarrah forest. The jarrah forest has a species rich flora, estimated to contain at least 784 plant species. Our research and monitoring has shown that within the forest vegetation types that we mine, there are approximately 300 plant species. The research and monitoring of our rehabilitated bauxite mines have shown that the species that first establish on a site, control the long term vegetation of the site. The vegetation, and the individual plant species are very resilient to natural forms of disturbance, so it is important to establish the correct flora early on. For this reason we aim to obtain high plant richness at the establishment phase of mine rehabilitation. Series of photographs of a rehabilitated area at Del Park mine near Dwellingup from 1990 to

8 THE CHALLENGE We wanted to increase the botanical richness measure of our mine rehabilitation from 65% to 100% within ten years while controlling the costs to the operation. This was a major challenge because in 1990 our practices were already industry-leading. We also knew that some of the missing plant species produced few seed, so their re-establishment would be difficult. Attempts were made to establish species using broadcast seed, but monitoring of the revegetated areas showed that some species were not germinating, despite their inclusion in the seed mix. There were also safety issues associated with handspreading the seed over uneven, ripped ground. From research in the late 70 s and 80 s we knew that directly returning topsoil to a rehabilitated area greatly increased botanical richness. But we also knew that planning for direct topsoil return could be complex and operational constraints could result in topsoil being stockpiled. So, part of the challenge was to affirm our commitment to best rehabilitation practices, improve our planning processes and implement the plans to maximise the direct return of topsoil. There were also challenges associated with rehabilitated areas that, through necessity, still received only topsoil that had been stockpiled. We knew that the botanical richness of these sites would be low because many of the seeds in the topsoil would have been killed during storage in stockpiles. Our understanding of the nature and enormity of the challenge was a valuable asset. There would be no easy fix. We could not learn from others, despite a number of benchmarking efforts, because none had addressed similar botanical richness goals and had succeeded. Improvements had to be made at all stages of rehabilitation. This would involve refining existing practices, developing new practices, developing better mine planning tools, developing new technology, and further increasing environmental commitment. OUR APPROACH The following components were important to our approach: Identify opportunities to improve the number of plant species. A systematic approach identified a wide range of opportunities. We then identified the feasible ones that required further investigation. Selecting research projects. Some projects were major investments with the involvement of universities and other research organisations. Other research took place in-house. The Environmental Research Group in Alcoa s Mining Department is composed of three experienced research scientists and six technical officers. Much of the in-house research was undertaken by this group with assistance from specialist personnel at the mines and Alcoa s nursery. Building the infrastructure and equipment. To apply the outcomes from the research projects there was a development phase. In this phase infrastructure such as a micropropagation laboratory was built, and equipment such as mechanical seeders and large-scale soil screens were designed and constructed. Tracking changes to botanical richness. Monitoring occurred every year using a scientifically-based sampling regime. Setting clear targets. We clearly stated our objective for the rehabilitated areas: To restore a functional jarrah forest ecosystem that fulfils the pre-mining land uses was a significant step forward. Senior management embraced this objective. In 1991 we developed a five year target called our Botanical Richness Milestone. The number of indigenous plant species in 15 month old rehabilitated areas is greater than or equal to 80% of the number found in representative jarrah forest sites. A new milestone was then written for year 2000 rehabilitation: The average number of indigenous plant species in 15 month old rehabilitation is 100% of the number found in representative jarrah forest sites, with at least twenty percent of these from the recalcitrant species priority list. Again, senior Alcoa management endorsed these targets and actions related to these milestones were included in strategic planning documents. 6

9 GERMINATING SNOTTYGOBBLES (PERSOONIA LONGIFOLIA) Snottygobble (Persoonia longifolia) is an ecologically important tree species in the jarrah forest in Western Australia but is not well-represented in jarrah forest restoration projects because it is difficult to germinate. In rehabilitated bauxite mines the establishment density of Snottygobble from the soil seed bank is variable and often inadequate. Alcoa considers it a priority to re-establish such key species at adequate densities in its restored mine areas. We found that the key to successful germination was combining surface sowing, seed-coat chipping and hormone (GA3) treatment. This germination method will have application to land managers, restoration practitioners and the horticultural industry. Alcoa will continue work to translate this success into an adequate stocking of Snottygobble in restored bauxite mines. A tree and a newly germinated seedling of Snottygobble (Persoonia longifolia). After three years of germination research experiments we have managed to achieve up to 40% germination of this important jarrah forest tree. Up to now no one has managed to germinate this species despite numerous attempts. We are now working to translate the successful germination treatment into production. 7

10 IMPROVEMENT ACTIVITIES TO REACH OUR TARGET In rehabilitated mines plants can establish from a range of sources: from applied seed, from the natural seed in the topsoil, by seeds from the neighbouring forest, and by planting. Planting was not part of our rehabilitation procedures in There was little or no pre-existing information about the biology or propagation of many of the plant species we wanted to re-establish; so a crucial part of our approach to meet the targets was an intensive research and development program. Some of these research findings are described here but others can be found in our published research papers (a list of relevant publications is included at the end of this nomination). Applied seed Each year we use more than four tonnes of native seed for our mine rehabilitation. All of this seed is collected within about 20 km from the mine where it will be used. Using local provenance correct seed ensures the genetic diversity of the restored areas is maintained. This self-imposed constraint makes the seed more expensive and difficult to collect but we think it is important if we are to truly restore the conservation value of the forest. Approximately five kilograms of seed are applied to each hectare of rehabilitated mine pit. The large Zamia palm seeds make up three to four kilograms of this. The seed mix includes the two dominant tree species and approximately 50 to 90 species of the ground flora. At the start of this project monitoring of rehabilitated areas found that some species reestablished well from seed but some species could not be found at all or were found at a very low density. An important part of the research program investigated why some species were not establishing from the seed mix. Alcoa developed this computer controlled air-seeder which delivers a calibrated amount of seed onto the freshly ripped ground. The air-seeder is used on the bulldozer during deep ripping. The two seed delivery pipes are clearly visible. 8

11 Seeds of many jarrah forest plant species are dormant and require different conditions or treatments to germinate. Many species from the Pea family (often called legumes) require a heat treatment before they will germinate. This is a natural adaptation that allows them to germinate after a fire or other disturbances in the forest. Through systematic testing, we determined the optimum heat (boiling water) treatments for the hard-seeded legume species. Many other native jarrah forest plants also germinate prolifically after forest fires, but did not respond to simple heat treatments. In 1994 researchers at Kings Park and Botanic Garden discovered that smoke is the stimulant, not heat. Alcoa helped fund this research and was directly involved in field and laboratory studies. About one third of the plant species in our seed mix were found to germinate better after smoke treatment; seeds of these species are treated with smoke before being sown in the rehabilitated mine pits. Our research program also discovered that the timing of seeding is important in the establishment of plants from applied seed. In the past, our procedure was to seed in early winter. This sowing time was based on a time-honoured agricultural practice to ensure that the seed germinated when the soil was wet and follow-up rains were expected. In the agricultural case premature germination can lead to false breaks or poor establishment of the crop. However, in our case, ripping occurs in summer to optimise the shattering of the sub-soil, so the seed broadcast in early winter was landing on a soil that had partly reconsolidated after autumn rains. We believed that this was decreasing seedling establishment, so we decided to challenge the applicability of this agricultural convention to the establishment of native vegetation. Laboratory and field trials showed that seed of most of our jarrah forest species would not germinate after rain unless soil temperatures were also low - so there was no risk of a false break after summer or early autumn rain. There were also other benefits to plant establishment if seed was sown immediately onto tilled soil. Seed burial and contact with the soil is improved and for some species, the natural cycles of soil heating and cooling and wetting and drying appear to improve germination rates. This maximised plant establishment from the applied seed and provided the opportunity to mechanise the seeding procedure. The procedure at that time involved hand seeding all rehabilitated areas. This is very strenuous work and there had been numerous cases of workers falling while walking across the uneven ground. Mechanising the procedure would remove this safety hazard. We developed a computer controlled air-seeding machine that attaches to the ripping bulldozer. Seed is broadcast directly onto the freshly ripped ground from the bulldozer. A key feature of the machine is its ability to handle mixed seed of varied size and shape. Another important feature is the mechanism used to deliver a very small amount of seed. The rate of seed application is about 1 to 2 kg per hectare (the large Zamia palm seeds which make up the largest proportion of the seed mix are applied separately by hand). It can take 3 to 4 hours to rip one hectare so the rate of delivery of seed needs to be very low. This was a difficult problem and was solved by using a slowly rotating sponge pad that was linked to the speed of the bulldozer. The seed is moved from the hopper area to the delivery tubes on the face of the rotating sponge. When the bulldozer stops the seed delivery stops. Seeds of Bull Banksia (Banksia grandis) Seed mixes being prepared at the Marrinup nursery for use in mine rehabilitation. 9

12 Natural seed from the topsoil Although applied seed can be used successfully to establish plants in rehabilitation, there are many species where seed collecting and subsequent broadcasting is impractical, very expensive or even impossible. For many of these species, the natural seed in the returned topsoil is the best way to re-establish these species in the rehabilitated areas. We have measured the density of natural seed in the forest topsoil, determined how deep the seed is buried in the soil and what happens to this seed over the different seasons. We have also studied what happens to the seed when the topsoil is moved and stored during mining and rehabilitation Forest 100% % 71.9% 89.4% 56.8% Cleared 73.9% mean in 88.2 stockpiled sites % 31.3% 39.7% direct returned topsoil Create Stockpile % 13.4% 12.4% 31.8% Respread % 15.5% 20.9% 52.7% Ripping Our research clearly showed that stockpiling of topsoil for even only one winter (our wet season) reduced the seed content to about 15%. Direct return of topsoil retained approximately half of the seed in the topsoil. The large numbers are the number of seeds per square meter. The other numbers are the percentage of seeds at each stage compared to the original forest sites. Season Germinable Seeds M -2 Summer 435 Autumn 265 Winter 207 Spring 261 Changes in the natural seed content of the topsoil clearly indicate that summer is the best season to use this valuable resource. Gompholobium knightianum readily establishes from the returned topsoil. 10

13 Cleared Forest Seeds dm-3 0-2cm 2-5cm 5-10cm 10-20cm rehabilitated mine pit from a cleared site and (2) transfer soil in summer. Monitoring the presence of plant species in rehabilitated mine pits also revealed a dramatic loss of seedlings when topsoil was ripped in autumn and winter compared with summer. In the jarrah forest topsoil, most of the seeds are in the upper 5 cm of the soil profile. We have also found that most jarrah forest plant species cannot germinate from deeper than about 5 cm. To make sure these seeds can successfully germinate, they need to be placed close to the final soil surface. To achieve this we remove and return the soil in two layers, keeping the seed-rich top layer at the top. Seedlings per m 2 Distribution of seeds in different depth intervals in the natural forest and after clearing. The seeds are mostly located near the soil surface. Our research found that most seeds cannot germinate from deeper than about 5cm so it is important that the top layers of soil be stripped off thinly and then returned at the top of the re-built soil profile Dec Feb Apr Jun Ripping Date Ripping in summer results in many more seedlings establishing from natural seed in the topsoil compared to autumn or winter ripping. There are instances where topsoil has to be stored. So when this soil is returned to a rehabilitated area the density of live seeds in the topsoil is low. We have developed a method to concentrate the seed in fresh topsoil so that pits that received the stored topsoil can also receive some seed-rich fresh topsoil. Concentrated topsoil from one hectare of forest can be used to significantly increase the numbers of plants and plant species on a much larger area of rehabilitation, up to 7 hectares. The method involves using small equipment, such as bobcats, to gather topsoil from future mine areas before the vegetation is disturbed. This occurs in summer when the seed density is highest. The topsoil is screened to remove soil particles greater than 5 mm diameter. The species richness of old stockpiled topsoil is increased by two to four-fold when this seed-rich topsoil is added as a thin top dressing. Because the seed has been concentrated in a smaller volume of soil it becomes more cost effective to transport the soil over long distances. To our knowledge this is the first case of seed concentrating technology being used in land rehabilitation anywhere in the world. We found that the jarrah forest topsoil naturally contains about 500 seeds of 40 to 70 plant species in every square metre. Two separate studies found that over 70% of the plant species growing in recently rehabilitated bauxite mines came from the natural seed in the topsoil. This highlighted the importance of maintaining the number of live seeds in the topsoil. We found that storing the topsoil in a stockpile for 10 months killed 85% of the natural seed in the topsoil. In the same experiment, 53% of the seed was preserved if the topsoil was removed from a newly cleared area of forest and then spread immediately on a nearby rehabilitated mine pit (we call this operation direct return ). Large changes in the density of natural seed in the topsoil was found between seasons, with summer having more than double the seed density compared with winter. Rehabilitation practices were changed to (1) maximise the amount of topsoil that is directly transferred to a Screened topsoil pouring onto a truck. This concentrated fines and seed fraction is then spread on rehabilitated mines. This practice can greatly boost the number of plants that establish on the rehabilitated areas and is used when fresh direct return of whole topsoil is not practical. 11

14 Dispersal of seeds into rehabilitated areas from neighbouring forest Natural dispersal of seeds and spores into rehabilitation is generally out of our control. However, there are ways to increase the likelihood of natural dispersal occurring. We remove any barriers to plant dispersal and animal recolonisation, such as roads and tracks around the edge of rehabilitated areas. Animals are important dispersers of many plant and fungal propagules. Fleshy-fruited jarrah forest plants are eaten by animals and then deposited into rehabilitated pits. Consequently, encouraging animals into rehabilitated areas is an approach to increase the richness of these types of plants. During the rehabilitation process we return wood debris and rocks both as small heaps and as scattered individual pieces to provide nesting and shelter to encourage animals to utilise the sites. Our animal research and monitoring programs have found that all jarrah forest mammal species, 90% of the bird species and 78% of the reptile species have recolonised the rehabilitated areas by the time they are 10-years-old. Some plant species are naturally introduced early into rehabilitated areas by animal vectors. Others, particularly orchids, are only found in rehabilitated areas that are older than about 5 years despite having seed that is as small as dust and is easily spread by the wind. The reason they take several years to return is because they need a particular fungus to be present in the soil. The orchid forms a partnership with the fungus which allows the orchid to survive and grow. The fungus is present in rehabilitation when substantial leaf litter has accumulated on the ground, which in turn depends on the growth of the vegetation. This is an interesting example of the importance of associations between different organisms and the development of a whole ecosystem. Seedlings of Leucopogon nutans, a native heath, germinating from an emu dropping that was deposited into a rehabilitated area. Emus are an important seed disperser for fleshy fruited plant species. Caladenia flava, an orchid that commonly returns naturally to rehabilitated areas after several years. 12

15 A fauna habitat structure in one year old rehabilitation. These are routinely placed in all rehabilitated pits and encourage the return of a wide range of vertebrate and invertebrate animals. 13

16 Planting of Recalcitrant species Often the dominant understorey plants in the jarrah forest are slow growing species that rely mainly on vegetative growth for spreading, and as a recovery response to fire. They do not produce viable seed, or if they do, it is difficult to collect or does not readily germinate. As a result, some of these species are under-represented in rehabilitated areas compared with the forest vegetation. These difficult or recalcitrant plant species often have important roles in the jarrah forest ecosystem. For example, common dry-land sedges are a significant food resource for kangaroos in the jarrah forest. They also resprout quickly and vigorously after disturbances such as fire and hence give the forest resilience. Hibbertia commutata, one of the recalcitrant species that is grown from cuttings for planting into the rehabilitated areas. It was obvious that planting would be required to re-establish these species. The decision to plant ground flora species was a major commitment by Alcoa to increasing botanical richness. The commitment involved the physical planting of the plants, but an even greater commitment had to be given to the research program to develop methods to propagate the species and to establish the nursery infrastructure to produce them. The annual cost of producing the plants and planting them is about $1300 per hectare. The first phase was to identify the recalcitrant species and develop methods to propagate them. Despite being common in the jarrah forest, little was known about how to propagate or grow most of these species - they are not used in the horticultural industry. The easiest method to grow these plants is from seed, although this often requires specific treatments to overcome seed dormancy. If this is not possible then divisions or cuttings are used. Tissue culture is the most difficult and expensive propagation method and is only used when other methods fail. The development of successful tissue culture methods is a very slow and expensive process and it can take several years to work out how to mass produce some species. A tissue culture laboratory at the nursery was first established and then enlarged to produce enough recalcitrant plants for all our mine rehabilitation areas. Research into propagating these recalcitrant plants began in the late 1980 s. The first experimental field planting was carried out in 1991 and production scale planting commenced in All rehabilitated mine pits are now planted with recalcitrant species. The number of recalcitrant plants established in rehabilitated mine pits has increased each year. Another important finding was that many of these species, particularly the grass-like rushes and sedges and the grass-trees, are the favourite food source for kangaroos in the rehabilitated areas. This has two important implications; firstly, that these species have an important function in the restored ecosystem and secondly, we need to protect the plants when they are small, otherwise they can be killed by overgrazing. Different methods of grazing protection are currently being investigated and a joint research project on kangaroo grazing in rehabilitated mines is underway at one of Perth s universities. A two year old Tetraria capillaris or hair sedge grown by tissue culture, in an experimental planting at Alcoa s Huntly mine. This species requires protection from kangaroo grazing. 14

17 Plants of recalcitrant species grown from cuttings at Alcoa s Marrinup nursery. Approximately 140,000 of these are grown each year for planting into Alcoa s rehabilitated bauxite mines. Tissue culture plants at Alcoa s tissue culture production facility at the Marrinup nursery. More than 100,000 recalcitrant plants are propagated in this way each year for planting in rehabilitated mines. Hair sedges grown by tissue culture and protected from grazing by a mesh onion bag. This type of guard is cheap and quick to apply and as can be seen in this photo, allows the plant to grow out through the mesh. The mesh is destroyed by prolonged sunlight and hence does not persist as an environmental hazard. 15

18 THE PREDICTED SPECIES INDEX (PSI) A MANAGEMENT TOOL TO APPLY R&D FINDINGS Thirty years of experience in rehabilitating bauxite mines meant that we knew a lot about which factors controlled the plant richness in rehabilitated areas. For example, the vital role of topsoil, and particularly fresh topsoil, as a source of seeds was well understood. We also had a substantial database from various research trials and experiments, which had information on plant species numbers on bauxite mines subjected to a range of different rehabilitation procedures. The problem was, how to apply this knowledge to a large mining operation to make sure that the best possible decisions were being made to gain the highest plant richness in the rehabilitated mine pits? We developed a model called the Predicted Species Index (PSI) which predicts the effect of various soil movement activities and dates of ripping and seeding on the resultant plant richness of a rehabilitated area. The output of the index is the predicted number of plant species that we will find when the areas are later assessed. For example, if the clearing, soil stripping, soil return and ripping are all carried out in quick succession in summer, and if the soil is stripped and returned in two layers, and the seed mix is applied immediately after ripping, then the rehabilitation will score a maximum PSI. If on the other hand the soil is stripped in winter, left in a stockpile for more than a year, returned and ripped in winter with a three month delay between ripping and seeding then the rehabilitation will score a minimum. The mines set PSI targets in their annual business plans. To achieve the PSI the rehabilitation plans have become an integral part of the overall mining plan. The mine planners and environmental staff aim to achieve an average PSI target of 80% of the number of species found in our jarrah forest control plots. The other 20% that we need to achieve our overall 100% target is provided by planting recalcitrant species. The model has been verified during the last 5 years and shows good correlation between predicted richness and the actual richness recorded at 15 months of age. The value of the PSI and the actual richness are now both used as annual performance measures for mine rehabilitation. The development of the PSI brought with it the need to improve record keeping. A comprehensive recording system for all pre-mining, mining, post-mining and other environmental information activities has been developed and implemented. The information is recorded on Alcoa s Geographic Information System (GIS) and is used constantly by environmental staff, mine planners, research students and many other users. Year Plants Species , , , psi , Production of recalcitrant plants from tissue culture, cuttings, divisions and seed for planting in bauxite mine rehabilitation. actual Graph of predicted species numbers from the PSI and actual numbers recorded in monitoring plots at the Huntly mine in The diagonal line indicates a perfect fit. The diamonds are plots in direct returned topsoil and the squares are stockpiled topsoil. The graph shows a good relationship between the model and actual species numbers. It also clearly shows the higher botanical richness achieved when fresh direct returned topsoil is used. Monitoring of our botanical richness performance is achieved using a rigorous and intensive assessment in spring each year. We monitor fifty 80m 2 plots each year at each mine. 16

19 OUR PERFORMANCE In 2000 we reached our target of 100% at our operating mines at Huntly and Willowdale. To measure botanical richness we developed a rigorous scientifically-based sampling system. Each year in spring, when the rehabilitation is 15-months-old, fifty 80m2 plots are randomly placed at each mine. We identify and count all local plant species in each plot so we can assess our progress towards our target. Identical control plots in the unmined forest adjacent to each mine are used to make the comparisons against. We started using this system in 1990 and since then we ve seen a continuous improvement in our results. Our efforts to achieve the 1996 target of 80% species richness were successful. Paying careful attention to handling and timing of topsoil movement, developing and applying new technology, putting new initiatives in place and improving the broadcast seed mix and its method of application saw a gradual improvement in species richness to over 80 % by By planting recalcitrant plant species we reached 96.8% in 1999 rehabilitation. In year 2000, the botanical richness of the two operating mines at Huntly and Willowdale was 100.7%. This is an area weighted average. During 2001, we also completed the final rehabilitation of the closed Jarrahdale mine. If we include Jarrahdale rehabilitation in the average, we achieved 97.4%. Haul roads, parking areas, crusher, workshop and office sites accounted for most of the rehabilitation areas at Jarrahdale. Many of these facilities had been in place for over 20 years and there was no opportunity to use direct return topsoil. We relied on the extensive use of screened topsoil imported from the Huntly mine and recalcitrant species planting to achieve the high botanical richness at Jarrahdale. 120 % of Jarrah Forest Controls year Graph of progress towards our year 2000 goal of 100% plant species richness. The value is an area weighted average of fifty 80m 2 plots at each mine for each year. 17

20 STRIVING FOR EXCELLENCE The Jarrah forest is a highly valued resource for the people of Western Australia. We believe that our mine rehabilitation needs to be of the highest standard and must exceed public and regulatory expectations if we are to retain access to the bauxite resource in this region. It is within this context that Alcoa has developed a scientifically based, best practice rehabilitation procedure. Alcoa was listed on the United Nations Environment Programme s Global 500 Roll of Honour in 1990 and remains the only mining company to have ever received this prestigious nomination. Since 1990 we have continued our pursuit of excellence and have improved greatly. This pursuit of excellence has again been recently recognised both within Australia and internationally when Alcoa was awarded a Golden Gecko, in 2002, by the Department of Mineral and Petroleum Resources and was the recipient of the Society for Ecological Restoration International s 2003 Model Project Award. Both awards acknowledged Alcoa for its work in returning the botanical richness of the jarrah forest in restored bauxite mines in Western Australia. We are committed to restoring a botanically rich jarrah forest vegetation in our mined areas. Sound environmental management is a key factor in all our operations. We are proud of what we do and each year over 8000 people visit our mines on public tours, as school groups, university field trips or as visiting scientists or other specialist groups. Although we have achieved what we believe is one of the highest standards in mine restoration worldwide, we still see opportunities for improvement. Continuation of research programs, implementation of better techniques and development of new and better technology remain integral parts of Alcoa s strategic plans for its Mining Department. We have not achieved our excellent results on our own. We acknowledge the great help we have received from our research colleagues and students in Perth s universities, research institutes and the collaboration from colleagues in CALM in implementing our operations. Hon. Clive Brown, WA Minister for State Development and Alcoa s Managing Director Wayne Osborn at the 2002 Golden Gecko award ceremony. 18

21 ALCOA S COMMITMENT TO IN-HOUSE AND EXTERNAL RESEARCH Alcoa has made a statutory and moral commitment to carry out and support scientific research in relation to its operations in Western Australia. We have strong links to all of WA s universities and to other research institutes such as the Australian Centre for Mining Environmental Research (ACMER) and Kings Park and Botanic Garden. We strongly fund and support basic and applied biological research by these organisations. Alcoa funded a lecturer position in plant ecology at the University of Western Australia from 1978 to This was seen as a need to establish a centre of excellence for study of native plant ecology in WA. Alcoa also funded a lectureship position in plant pathology at Murdoch University from 1994 to Again, this developed a centre of excellence in Western Australia to study plant diseases, and particularly Phytophthora dieback disease. Alcoa environmental staff have supervised or co-supervised approximately one hundred honours, masters and Ph.D. students over the years. Alcoa also financially supports these projects. In 1999, 2000 and 2001 we had 28 students working with us. These projects provide Alcoa with important research information and give the students valuable training in environmental matters associated with the resource sector. All environmental management type courses in Western Australian universities include at least one visit to Alcoa s mine rehabilitation operations. Several courses also include one or more lectures from Alcoa environmental staff. A significant flow-on benefit is that these students, their university supervisors and other associated researchers communicate the research results to the rest of the resource sector. Also many of these students are subsequently employed in the resource sector. Year No. of Postgraduate No. of Undergraduate projects projects Students working on Alcoa mining environmental projects in 1999, 2000 and Each year the students who are involved in Alcoa related research projects are invited to give a presentation at a group seminar. The 1998 group pictured here includes 19 students and their University supervisors as well as Alcoa environmental staff. 19

22 PUBLICATIONS, DOCUMENTS AND REPORTS At Alcoa we publish and disseminate the results of our environmental research so that it is freely available to the public, other researcher groups, other mining companies and Government institutions. The Environmental Research Note Number 18, Seed Germination Records from Alcoa s Marrinup Nursery (see Koch, J.M. & Taylor, S.K. in the list below) was published in direct response to many public and research enquiries about seed germination of native WA plant species. Alcoa s environmental research staff in Western Australia have published over 90 refereed journal papers and book chapters, 49 Alcoa Research Notes and Bulletins and more than 90 printed conference papers. Some of the key ones that relate to this nomination are listed below. Alcoa authors are underlined. Baker, S.R., Gardner, J.H. and Ward, S.C. (1995). Bauxite mining environmental management and rehabilitation practices in Western Australia. World s Best Practice in Mining and Processing Conference, Sydney May, Bartle, J. and Slessar, G.C. (1989). Mining and rehabilitation. Chapter 19 in The Jarrah Forest (Eds. B. Dell et al.), Kluwer Academic Publishers, Dordrecht. Bell, D.T., Plummer, J.A. & Taylor, S.K. (1993). Seed germination ecology in Southwestern Western Australia. Botanical Review 59(1): Carbon, B.A. (1981). Bauxite mining on the Darling Plateau, Western Australia. UNEP Industry and Environment 4, Collins, B.G., Wykes, B. and Nichols, O.G. (1985). Recolonisation of restored bauxite minelands by birds in Southwestern Australia. In: Birds of Eucalypt Forests and Woodlands : Ecology, Conservation and Management (Eds. A. Keast and H. Recher), Surrey, Beatty and Sons, Sydney. Curry, P.J. and Nichols, O.G. (1986). Early regrowth in rehabilitated bauxite mines as breeding habitats for birds in the jarrah forest of South-Western Australia. Australian Forestry 49(2), Elliott, P.E. and Wake, G.W. (1992). The integration of environmental management into mine planning using a geographic information system: the Alcoa experience. Geological Applications of Geographic Information Systems (GIS), AIG Bulletin 12, Elliott, P.E. and Wake, G.W. (1995). Environmental applications of a geographical information system within Alcoa of Australia. In: proceedings of WALIS Forum 95, Perth 8-9 February Gardner, J.H. (2001). Rehabilitating mines to meet landuse objectives: bauxite mining in the jarrah forest of Western Australia. Unasylva 207, 3-8. Gardner, J.H. and Malajczuk, N. (1985). Succession of ectomycorrhizal fungi associated with eucalypts on rehabilitated bauxite mines in south western Australia. In: Proceedings of the 6th North American Conference on Mycorrhizas, Bend, Oregon. Gardner, J.H. and Malajczuk, N. (1988). Recolonisation of rehabilitated bauxite mine sites in Western Australia by mycorrhizal fungi. Forest Ecology and Management 24, Grant, C.D., Bell, D.T., Koch, J.M. and Loneragan, W.A. (1996). Implications of seedling emergence to site restoration following bauxite mining in Western Australia. Restoration Ecology 4(2), Kabay, E.D. (1986). Advances in rehabilitation horticulture. Australian Horticulture, April 1986, p86. 20

23 Kabay, E.D. and Lewis, A. (1987). The collection, handling and storage of Australian native plant seed. In: Germination of Australia Native Plant Seed (Ed. P. Langkamp). Australian Mineral Industries Research Association, Canberra. Koch, J.M. (1998). Restoration for biodiversity: Alcoa s Western Australian bauxite mines, In papers of Biodiversity, Biotechnology & Biobusiness 2nd Asia-Pacific Conference on Biotechnology, Perth, November 1998, p Koch, J.M. and Ward, S.C. (1994). Establishment of understorey vegetation for rehabilitation of bauxite-mined areas in the jarrah forest of Western Australia. Journal of Environmental Management 41, Koch, J.M. and Taylor, S.K. (2000). Seed germination records from Alcoa s Marrinup Nursery. Environmental Research Note No. 18. Koch, J.M., Taylor, S.K. and Gardner, J.H. (1994). Research to maximize plant diversity in rehabilitated bauxite mines in the jarrah forest. National Workshop on Native Seed Biology for Revegetation. Perth August Koch, J.M., Ward, S.C. and Grant, C.D. (1996). Soil seed bank research for mine rehabilitation: a case study of bauxite mining in a species-rich ecosystem in south-west Western Australia. In Proceedings of Second Australian Native Seed Biology for Revegetation Workshop (Eds Bellairs, S.M. and Osborne, J.M.), Newcastle, October, 1996, p Australian Centre for Minesite Rehabilitation Research. Koch, J.M., Ward, S.C., Grant, C.D., and Ainsworth, G.L. (1996). Effects of bauxite mine restoration operations on topsoil seed reserves in the jarrah forest of Western Australia. Restoration Ecology 4(4), Mullins, R.G., Koch, J.M. and Ward, S.C. (2002). Practical method of germination for a key jarrah forest species: Snottygobble (Persoonia longifolia). Ecological Management and Restoration 3(2): in press. Murphy, B.P. and Loneragan, W.A. (1999). The distribution of seed sizes in concentrated topsoil.. In Proceedings of Third Australian Workshop on Native Seed Biology for Revegetation. (Eds C.J. Asher and L.C. Bell), Perth, May, 1999, p Australian Centre for Mining Environmental Research. Nichols, O.G. (1998). The development of a rehabilitation program designed to restore a jarrah forest ecosystem following bauxite mining in south-western Australia. Proceedings of the Fourth International Conference of the International Affiliation of Land Reclamationists Nottingham, United Kingdom 7-11 September, Nichols, O.G. and Bamford, M. (1985). Reptile and frog utilisation of rehabilitated bauxite minesites and dieback affected sites in Western Australian jarrah (Eucalyptus marginata) forest. Biological Conservation 35, Nichols, O.G. and Michaelsen, D.V. (1986). Successional trends in bauxite mines rehabilitated using three topsoil return techniques. Forest Ecology and Management 14, Nichols, O.G. and Muir, B. (1989). Vertebrates of the jarrah forest. In : The Jarrah Forest (Eds. B. Dell et al.), Kluwer Academic Publishers, Dordrecht, The Netherlands. Nichols, O.G. and Watkins, D. (1984). Bird utilization of rehabilitated bauxite minesites. Biological Conservation 30, Nichols, O.G., Majer, J.D. and Wykes, B.J. (1989). The return of vertebrate and invertebrate fauna to bauxite mined areas in Australia. Chapter 16 in : Animals in Primary Succession - the Role of Fauna in Reclaimed Lands (Ed. J.D. Majer), Cambridge University Press. Plummer, J.A., Crawford, A.D. and Taylor, S.K. (1995). Germination of Lomandra sonderi (Dasypogonaceae) promoted by pericarp removal and chemical stimulation of the embryo. Australian Journal of Botany 43,

24 Roche, S., Koch, J.M. and Dixon, K.W. (1997). Smoke enhanced seed germination for mine rehabilitation in the southwest of Western Australia. Restoration Ecology 5 (3), Slessar, G.C. (1989). Putting back the forest. Prospect, Summer 1989/90, 6-11, W.A. Dept. Resources Development. Slessar, G.C. and Foster, M.B. (1987). Rehabilitation after bauxite mining. In : Mining and Rehabilitation 87 (Ed. T. Farrell), Australian Mining Industry Council, Canberra. Tacey, W.H. (1978). Establishment and diversity of jarrah forest flora on bauxite mined areas. Proceedings of a meeting on Rehabilitation of Mined Lands in Western Australia, (Ed. J.E.D. Fox), Western Australian Institute of Technology, Perth. Tacey, W.H. and Glossop, B.L. (1980). Assessment of topsoil handling techniques for rehabilitation of sites mined for bauxite within the jarrah forest of Western Australia. Journal of Applied Ecology 17, Taylor, S.K., Luscombe, P. and Hill, G. (1994). Planning and designing seed mixes. In: Proceedings of Workshop 3 - Revegetation of Mine Sites using Appropriate Species (Third International Conference on Environmental Issues and Waste Management in Energy and Mineral Production) Perth, pp Ward, S.C (2000). Increasing Botanical Diversity. Best Practice 2000, pp The Yearbook of Best Practice Environmental Management in the Minerals and Energy Industries. Australian Minerals and Energy Foundation. Ward, S.C. (2000). Soil development on rehabilitated bauxite mines in south-west Australia. Aust. J. Res., Ward, S.C. and Koch, J.M. (1999). A novel method to concentrate seed in the topsoil for bauxite mine rehabilitation.. In Proceedings of Third Australian Workshop on Native Seed Biology for Revegetation. (Eds C.J. Asher and L.C. Bell), Perth, May, 1999, p Australian Centre for Mining Environmental Research. Ward, S.C. Slessar, G.C. and Glenister, D.J. (1993). Environmental resource management practices of Alcoa of Australia Limited. In Australasian Mining and Metallurgy. (Eds. J.T. Woodcock and J.K. Hamilton) pp Second Edition, Volume 1. Ward, S.C., Koch, J.M. & Baird, G.J. (1994). The predicted species number index : a quality management tool for rehabilitation. In papers of the Australian Mining Industry Council Environmental Workshop, Karratha. Ward, S.C., Koch, J.M. and Ainsworth, G.L. (1996). The effect of timing of rehabilitation procedures on the establishment of a jarrah forest after bauxite mining. Restoration Ecology, 4(1), Ward, S.C., Koch, J.M. and Grant, C.D. (1997). Ecological aspects of soil seed-banks in relation to bauxite mining. I. Unmined jarrah forest. Aust. J. Ecol. 22, Ward, S.C., Koch, J.M. and Nichols, O.G. (1990). Bauxite mine rehabilitation in the Darling Range, Western Australia. Proc. Ecol. Soc. Aust., 16,