1. The Australian context

Australia is a large island continent (approx. 7.7 M square km) that constitutes just over 5% of the world's land mass. The continent is old and in geological terms relatively undisturbed with the most recent volcanic events occurring on the Newer Volcanic Province from central Victoria to southeastern South Australia between 4.5 M and 10, 000 and possibly 5000 years ago (Smith and Prescott, 1987; Joyce, 2005; Lesti et al., 2008). It is also extremely flat with an average elevation of 300 m ranging from 15 m b.s.l. at Lake Eyre to 2228 m a.s.l. at Mt Kosciusko. While a large part of the Australian interior is hot and dry, monsoon tropics occur in the north with wetter tropical to temperate zones in the east and southwest (Joseph et al., 2014). Australian soils are generally poor and many plant groups have evolved mechanisms to increase nutrient uptake such as symbioses with nodulating bacteria and mycorrhizal fungi or morphological adaptations such as cluster roots (Shane and Lambers, 2005).

Approximately 10% of the global biota occurs in Australia, primarily due to a long and isolated evolutionary past that began when the ancient Gondwanan super continent began to breakup with Australia drifting northwards and becoming completely isolated some 40-50 MYA (Lawver and Gahagan, 2003; Bijl et al., 2013; Scher et al., 2015). Following separation from Gondwana in the Miocene, Australia began drying and this period in time coincides with the evolution of many important plant lineages such as Acacia (wattles) and Eucalyptus (gum trees) (Joseph et al., 2014). Unlike the northern hemisphere where ice sheets dominated many terrestrial environments, Australia remained mostly ice free (Williams, 2000, 2001). Aridification began some 15 MYA with arid landforms appearing approx. 1-4 MY later (Bowler et al., 2006; Fujioka et al., 2009); the evolution of arid zone species and arid-adapted taxa from mesic-adapted ancestors is evident during this time (Byrne et al., 2008). In contrast, mesic habitats contracted leading to the extinction of numerous lineages, especially in rainforest communities, although these communities experienced immigration from northern neighbours (Byrne et al., 2011a). Australia is now home to an extremely diverse biota of somewhere between 600, 000 and 700, 000 species that includes more than 21, 000 plants, 7300 vertebrates and approximately 200, 000 insects; 84% of these plants, 83% of the mammals, and 45% of Australian birds are endemic (Chapman, 2009, Table 1; http://www.environment.gov.au//threatened-species-ecological-communities).

While Australia has a rich diverse and unique flora distributed across the continent, two regions in particular, the southwest and the forests of east Australia, highlight the importance of ongoing plant conservation efforts given their recognition as global biodiversity hotspots. These areas harbour a large number of plant species including many of Australia's threatened species and are recognised because of the concentration of endemic plant species combined with an exceptional loss of habitat. Specifically, international biodiversity hotspot regions contain at least 1500 species of vascular plants as endemics and have lost ≥70% of their original native habitat (Mittermeier et al., 2011), with the Southwest most recently estimated to have 3911 species (Gioia and Hopper, 2017) and the east Australian forests more than 2144 endemic plant species (Williams et al., 2011). The uniquely flat and ancient landscapes of southwestern Australia have received particular attention recently as very old, climatically buffered, infertile landscapes (Ocbils) (Hopper, 2009; Hopper et al., 2016) which are typical of a number of Mediterranean terrestrial biodiversity hotspots; as such, these may warrant special treatment in conservation and restoration efforts. While both of these internationally recognised biodiversity hotspots deserve attention in plant conservation efforts, there are many other regions across Australia that require and are the focus of conservation and restoration initiatives. It is clear that managing such a diverse flora across such a large continent is an ongoing challenge if the decline of a significant number of species is to be reversed. Here we present an overview of current approaches and challenges to plant conservation in Australia. We emphasise the need for knowledge and learning from management experiments, the importance of strategic long term conservation commitment, the value of restoration initiatives and the need to improve community engagement.

1.1. Managing Australia's biota

Most of Australia's land environment is managed by State and Territory agencies who are responsible for public land of various tenures, family and corporate agricultural and pastoral businesses and Indigenous Australians; Federal and Local governments manage smaller but significant areas (Department of the Environment Water Heritage and the Arts 2009, 2008). About 25% of Australia is managed for conservation (State of the Environment, 2011 Committee, 2011) although concerns have been raised whether the current National Reserve System will be suitable under climate change (Mackey et al., 2008). The Federal Government Environmental Protection and Biodiversity Act 1999 (EPBC Act) is responsible for matters of national significance while each Australian State and Territory has its own legislation to conserve and manage the species within jurisdictional boundaries (Table 2).

Australia is also a signatory to many international agreements to conserve species such as the Convention on Wetlands (Ramsar Convention) as well as regional strategies such as the East Asian–Australian Flyway Partnership for migrating birds. Misalignments of species listings across the various State, Territory and Federal jurisdictions do exist although there is considerable goodwill among the agencies charged with managing these species lists to reduce misalignments as much as possible. These misalignments can arise for several reasons such as differences in the legislated threat categories of the various conservation Acts (Table 2) and the intent of the EPBC Act being to address matters of national significance whereas the State and Territory governments are responsible for conservation matters within their own borders. Misalignment can also occur when a species is unequally distributed across jurisdictional borders. For example, if the majority of individuals occur in one jurisdiction it may be classified as 'Vulnerable' whereas the considerably fewer individuals in the other jurisdiction may be considered to be 'Critically Endangered'. While this has the potential to lead to different management actions based on contrasting threat categories, cross-jurisdictional cooperation helps to align management actions to benefit all of the individuals, thus improving the status of the species as a whole. To further improve cross-jurisdictional efforts Australian Environment Ministers agreed in 2014 to support the National Review of Environmental Regulation to build on existing regulation reforms underway across jurisdictions (Department of Environment and Energy, 2015). The number of species protected by each State and Territory varies considerably with Western Australia and Victoria being responsible for managing a largest proportion of threatened species (3501 and 1943 respectively; Table 3).

2. Challenges for Australian plant conservation

Some significant challenges exist for plant conservation across Australia including mitigating the impacts of major threatening processes associated with habitat loss and invasive species, raising awareness of the cultural and socio-economic value of plant conservation, dealing with the nation-wide loss of taxonomic expertise despite the rich and diverse flora, and improving our understanding of the biology of the many plant species targeted for conservation actions. The most recent Australian State of the Environment Report highlights increasing threats to and ongoing decline of biodiversity with no real improvements in key performance indicators since the previous report in 2011 (Cresswell and Murphy, 2017). It is no surprise that many of the most threatened Australian species coincide with agriculture regions and urban environments where natural landscapes have been extensively modified and vegetation fragmentation is high (see Fig 8.4 in State of the Environment, 2011 Committee, 2011).

2.1. Threatening processes

Over the last three decades it has become increasingly clear that targeted active management of reserves, specific threatened communities and populations of threatened plants will need to be implemented across Australia at levels not previously envisaged. Widespread land clearing and habitat loss, anthropogenically-driven habitat fragmentation, invasive species, introduced diseases, inappropriate fire regimes and hydrological change are all significant factors in ongoing biodiversity decline. Superimposed on these threatening processes is climate change that, when combined with threats such as habitat fragmentation and disease, is predicted to substantially increase the magnitude of adverse impacts on the flora (Yates et al., 2010).

The decline in vegetation throughout significant areas of Australia is associated to a large degree with widespread land transformation for agriculture. This in turn has, either directly or indirectly, led to major habitat fragmentation now being one of the most important factors affecting the persistence of species and species assemblages in a number of Australian ecosystems (Young and Clarke, 2000; Hobbs and Yates, 2003). Habitat fragmentation has been found to result in a range of negative impacts on ecological and genetic processes in plant populations (Broadhurst and Young, 2007; Yates et al., 2007; Llorens et al., 2012, 2013) and has also led to significant habitat degradation associated with grazing, inappropriate fire regimes, nutrient enrichment, soil disturbance via rabbits and a broad range of invasive weeds. In some landscapes, such as in southwest Australia, there are indications that plant species may be resilient to habitat fragmentation with evidence that they were probably able to persist in small populations prior to land clearing (James, 2000; Hopper, 2009). Yet ongoing habitat loss, population isolation and further reduction in population size are still likely to lead to increased population extinction risk associated with habitat degradation and competition with invasive species (James, 2000; Yates and Broadhurst, 2002). For example, investigations of the impacts of fragmentation on a rare historically-isolated species in the southwest, Calothamnus quadrifidis subsp. teretifolius, show no effect of population size or isolation on mating system and reproductive output. However, impacts of disturbance associated with a high density of weeds are evident in a lack of recruitment of populations in degraded remnants (Gibson et al., 2012).

In Australian ecosystems inappropriate fire regimes have been identified as a major threat of growing importance for Federally-and State-listed threatened plant species (Coates and Atkins, 2001; Burgman et al., 2007). Many plants found in forests, woodlands and heathlands of temperate Australia are threatened by particular combinations of fire frequency, intensity and season that interrupt their life cycle processes failing to produce adequate cues that are critical to germination, recruitment or reproduction. While there is variation in Australian plant species relating to survival, reproduction, dispersal and establishment post fire, changes in the fire-regime relative to historical patterns brought about by European settlement and land-use can result in species declines (Keeley et al., 2011) particularly in the case of rare species such as narrowly endemic serotinous shrubs (Yates et al., 2003).

Disease is often not highlighted as much as other threats to the Australian flora but two introduced pathogens in particular, Phytophthora dieback (Phytophthora cinnamomi) and Myrtle rust (Puccinia psidii), are being increasing recognised not only because of impact these diseases are already having on diverse native plant communities and many rare and threatened species, but also because of the major difficulties in effective control. P. cinnamomi has been listed as one of the world's most destructive invasive species (Lowe et al., 2000) and its historical and predicted future spread into vulnerable Australian plant communities in NSW, Victoria, Tasmania and Western Australia is already resulting in significant permanent loss of biodiversity (Shearer et al., 2007; Cahill et al., 2008). Unlike Phytophthora dieback which has been in Australia for many decade, Myrtle rust has only recently arrived. Yet by 2014 it has proved capable of infecting more than 300 native Australian Myrtaceae species. Nearly half of the 2250 native species of Myrtaceae occur in the climatic areas assessed as suitable for the disease making the potential impact on threatened species, plant communities and in some cases whole ecosystems significant (Makinson, 2014). Already rare and endangered species such as Gossia gonoclada are under severe threat (Taylor et al., 2017) and it has been listed as a Key Threatening Process in NSW since 2012.

2.2. Public awareness and support for plant conservation

A key challenge for effective plant conservation in Australia is raising public awareness about the cultural, social and economic value of conserving Australia's rich, unique and diverse plant species and communities. Recently the issue of "plant blindness" has been raised highlighting the fact that plant conservation initiatives often fall behind those targeting animals, particularly mammals and birds (Balding and Williams, 2016; Cochrane, 2017). In many cases there is far less funding for plants (see Section 3), despite the critical role that plants play in providing food and shelter for animals, and perceptions that plants are more easily recovered from decline than animals. This clearly indicates a bias towards animals and a tendency among humans to neither notice nor value plants in the environment (Balding and Williams, 2016). While there is significant community interest and support for plant conservation in Australia it tends to be fairly narrow in focus and is often reliant on NGO groups such as the Australian Network for Plant Conservation (http://www.anpc.asn.au/) and Greening Australia (https://www.greeningaustralia.org.au/). Some iconic plants groups such as orchids and species such as the Wollemi pine (Wollemia nobilis) do garner strong public support suggesting that it is possible to raise awareness and engage communities by better understanding the appeal of these projects. Government agencies play a pivotal role in biodiversity conservation in Australia and given the number of threatened plant species (Table 3) a more equitable approach to their conservation and management could make a significant difference to their recovery and improved conservation status.

2.3. Taxonomy

One of the most significant obstacles to effective plant conservation is lack of taxonomic knowledge and the ability to readily identify plant taxa in the field (Coates and Atkins, 2001; Wege et al., 2015). This is particularly evident in floristically rich areas such as the southwest and Kimberley regions of Western Australia. For example, the extent and completeness of taxonomic knowledge in Western Australia can be judged from the number of known taxonomic entities that have not yet been formally named. To date, 1245 taxa, 10% of the State's flora (https://florabase.dpaw.wa.gov.au/statistics/), are listed under phrase names representing plant morphological variants that are believed to characterise new taxa (species, subspecies) but have not yet been subjected to the rigorous taxonomic scrutiny required before these can be given a scientific name. Decreasing taxonomic capacity across Australia is a growing concern and limitation given the increasing conservation issues requiring some level of taxonomic input. While strategic approaches have been developed recently to deal with taxa that require taxonomic resolution to improve knowledge for conservation management (Wege et al., 2015), there is still an imperative to maintain taxonomic resources to deal with ongoing name changes, species descriptions and new species discoveries that are critical for the increasing number of species conservation assessments undertaken, as well as and the listing of species of conservation concern. This lack of taxonomic capacity can also be a serious impediment when considering applications such for mining or urban development.

2.4. Lack of biological knowledge

Another challenge for plant conservation is the limited biological information for the vast majority of Australian species. While some generalisations can be made for larger plant groups (e.g. Broadhurst and Young, 2007), this limited knowledge is a significant issue particularly for our most threatened taxa, impacting on our ability to arrest decline and begin the process of species recovery (e.g. Broadhurst et al., 2016a). One area in particular that is often overlooked are plant–animal interactions and the role and importance of associated organisms such as pollinators, herbivores, dispersers and symbionts. For example, some of Australia's rarer legumes appear to have quite specific associations with symbiotic nodulating bacteria (Thrall et al., 2000) suggesting that the loss of either species will compromise successful plant conservation. This is especially concerning for rare species held in conservation seed banks since successful reintroduction may be contingent upon having the appropriate symbiont in the reintroduction site. An intimate association between the threatened Banksia brownii and the associated herbivorous plant-louse (Trioza barrettae) further highlights the need to consider dependant organisms in addition to their threatened host when carrying out recovery actions targeting the host. In this case, the plant louse is likely to be more susceptible to extinction than the host (Moir et al., 2016). Some sexually deceptive Australian orchids have also been shown to have very specific pollinator associations (Peakall et al., 2010; Phillips et al., 2015) and ensuring that both pollinators and mycorrhizal fungi are present can be key to the success of orchid reintroduction programs (Reiter et al., 2016). In all these cases improved knowledge of the threatened species and co-dependent species is important for achieving effective conservation outcomes.

Although a focus in conservation biology for a number of decades the application of genetic approaches has not only highlighted the value of such information in the conservation and restoration of Australia's flora but has also emphasised significant gaps in our understanding of genetic processes and their links to demographic outcomes and extinction vulnerability. Data is now available for a good number of species across Australia including many rare and threatened species (Broadhurst et al., 2017) and genetic assessment frameworks have been developed to encompass the management of threatened plant species with a range of life history traits (Ottewell et al., 2016) and when evaluating genetic risks in translocations (Weeks et al., 2011) and restoration (Byrne et al., 2011b). Yet it is evident that some species may have unusual genetic systems and be more tolerant to inbreeding effects in small populations with reduced extinction vulnerability (see James, 2000; Hopper, 2009). At the same time there are a number of studies on the Australian flora which have found strong evidence for inbreeding (Coates et al., 2007), inbreeding depression (Llorens et al., 2012, 2013) and elevated interspecific hybridisation (Field et al., 2008) associated with recent habitat fragmentation and small, isolated populations in highly disturbed habitats. These contrasting findings highlight the broad genetic responses found in plant populations where vegetation has been removed and fragmented, and the ongoing need for a better understanding of the diverse genetic systems that characterise the Australian flora. These studies demonstrate that despite the often useful generalisations that can be made regarding the genetic consequences of habitat fragmentation, management strategies may still need to be developed that are appropriate only for individual species and their landscape context.

3. Conservation investment

The Australian Federal government has invested in improving biodiversity across Australia by funding a range of programs since the late 1980s following introduction of the National Landcare Program (Table 4). Considerable funding to address issues of biodiversity decline has also been allocated by State and Territory governments as well as by numerous small land holders (Smith, 2008). These programs have often adopted a multifaceted approach to conservation ranging from funding infrastructure such as fencing to keep stock from grazing remnant vegetation and riparian zones to direct on ground actions such as restoration plantings and species recovery projects. However, despite 1307 plant species being listed under the EPBC Act (Table 3), an order of magnitude higher than the number of mammals (121) and birds (138) that were listed, funding inequalities between plants and animals remain. The $60M+ National Environmental Science Programme (NESP) Threatened Species Hub established in 2015 (http://www.nespthreatenedspecies.edu.au/about) has funded 22 projects to date (Table 5). Two projects are focused entirely on plants, developing an early-warning tool for plant species most at risk (2.4) and improving threatened plant reintroductions (4.3); five other projects will be beneficial to plant conservation through the conservation of critical and threatened habitats (1.2), managing fire regimes and thresholds (1.3), development of a threatened species index to provide a reliable measure of population trends (3.1), practical adaptive management to improve threatened species conservation programs (3.3) and improving assessments and policy options for poorly-known threatened species (5.2). Several other projects (e.g. 4.2, 4.4 and 6.4) may also improve Australian plant conservation but it is difficult to determine the scale of this benefit from the information that is currently available. There also continues to be significant investment by State governments with recent initiatives in NSW involving a pledge of $100 million over five years to protect the State's threatened species (http://www.environment.nsw.gov.au/topics/animals-and-plants/threatened-species/saving-our-species-program). While it is not clear how much of this will be allocated to plants this is nevertheless a significant conservation initiative. The new funds will allow the NSW Saving our Species program to expand to cover more species as well as threatened ecological communities and key threatening process.

Other important investment in plant conservation comes through non-government organisations and community groups. There continues to be a significant level of community interest and support for organisations such as the Australian Network for Plant Conservation (ANPC). Since its inception 25 years ago, the ANPC has played a very active role in threatened plant species management and recovery in Australia, particularly through its contribution to threatened plant translocations and associated surveys, propagation, habitat restoration, ex situ seed collections, research and monitoring (http://www.anpc.asn.au/). This has been achieved through various on-ground activities and a number of key publications such as the ANPC's Translocation Guidelines and Germplasm Guidelines (Vallee et al., 2004; Offord and Meagher, 2009).

4. Conservation approaches

As is done in many countries, Australian approaches to conservation are both species-and landscape-based. This has involved the establishment of protected areas through a system of conservation reserves and covenants, improved management of reserves, management of other government land and private remnant vegetation, protection of flora through legislation, and the recovery and restoration of species and communities. In 2011, seven large-scale connectivity conservation areas were initiated to help interconnect protected areas and to maintain large-scale natural Australian landscapes and ecosystem processes (Worboys and Pulsford, 2011). These include the Great Eastern Ranges Corridor (2800 km) in the east, the 3000 km Northern Australia Tropical Savannah Lands Corridor that includes the Kimberley Landscape Conservation Area in the north, Gondwana Link (1000 km) in the southwest and through the centre of Australia, the 3500 km Trans-Australia Ecolink Corridor; other important large-scale corridors are Habitat 141 and Biolinks (Worboys and Pulsford, 2011). The $20 M Federally-funded 20 Million Trees program is also expected to re-establish green corridors as well as urban forests (http://www.environment.gov.au/land/20-million-trees). This connectivity involves grass roots organisations, non-government conservation organisations, governments or a combination of these organisations and uses de-centralised governance approaches which include multiple partnerships with a shared vision for the corridor as a whole and within component links (Worboys and Pulsford, 2011). While it has been argued that corridors per se in some regions with "old climatically buffered infertile landscapes" are unsuitable (Hopper, 2009; Hopper et al., 2016) we suggest that the value of these initiatives is perhaps not so much in re-establishing connectivity across the landscape but is more in re-establishing native vegetation at a scale that ultimately leads to diverse self-sustaining communities and ecosystems. Several hundred Indigenous Australian communities are also now involved in the management of their local areas including some of the most remote parts of Australia (State of the Environment, 2011 Committee, 2011). However, despite the vast wealth of traditional knowledge in these communities, a recent review indicated that only 19% of Indigenous biocultural knowledge documentation has coincided with Indigenous Protected Areas despite the role that this knowledge can play in plant conservation both on and off traditionally managed lands (Ens et al., 2015; Lullfitz et al., 2017).

Improving species-level conservation for rare and threatened taxa at the Federal-level has recently shifted. In 2014, the first Threatened Species Commissioner was appointed to bring a new national focus to conservation efforts for threatened flora and fauna (http://www.environment.gov.au/biodiversity/threatened/commissioner/role) and in 2015 the Federal Government launched Australia's first Threatened Species Strategy (Commonwealth of Australia, 2016). This strategy provides a national approach dedicated to the recovery of threatened plants and animals based on science, action and partnership (Commonwealth of Australia, 2016). For plants the strategy aims by 2020 to have 100% of Australia's known threatened species in conservation seed banks, recovery actions are underway for at least 50 plants and 60 threatened ecological communities and improve the trajectories of 30 priority plants (Commonwealth of Australia, 2016). The strategy also sets key action areas and targets against which success can be measured as well as providing guidance and support for recovery teams (http://www.environment.gov.au/biodiversity/threatened/recovery-teams). More recently, the Threatened Species Prospectus was released to encourage broader engagement from Australian business, industry and philanthropic communities to help prevent species extinctions (http://www.environment.gov.au/biodiversity/threatened/publications/threatened-species-prospectus).

Until recently much of the conservation of threatened plant species in Australia has focussed on in situ conservation approaches such as management and protection of vegetation, and managing and mitigating threating processes. While it is clear that these approaches can be effective in many cases, it is also evident that these are unlikely to prevent the decline of significant number of threatened plant species. Many of these species currently exist as small populations on linear remnants with significant weed invasion and show substantial reduction in reproductive output and very limited recruitment (Coates et al., 2014). Other threatened species are highly susceptible to Phytophthora dieback with all populations infected and in decline, and current management options provide no avenue for controlling the disease (Coates et al., 2014). Lately it has become clear that a more strategic approach for managing rare and threatened plants such as B. brownii (Coates et al., 2014) and many other species threatened by Phytophthora dieback (Shearer et al., 2004) requires a combination of in situ and ex situ conservation. Ex situ conservation plays a significant role by conserving components of plant diversity outside their natural habitats, for example as seed in conservation seed banks. Ex situ collections of plant germplasm, primarily seed, are not only valuable for the protection and safe keeping of genetic resources, but also provide material for recovery actions, such as translocations and restoration (see Cochrane et al., 2007; Offord and Meagher, 2009). Many situations will justify the need for either long-or short-term ex situ storage of seed resources where the effective management of a threatening process, such as Phytophthora dieback and myrtle rust, is limited. In these cases, backup conservation seed storage facilities have been established around Australia (http://www.seedpartnership.org.au/) to collect and maintain seeds of rare and threatened species, with a primary objective of future translocations. While most plant recovery programs for both rare and common species expect to use seed, concerns have been raised by restoration researchers and practitioners for several decades that native vegetation is unlikely to be able to provide the amount of seed required for restoration activities. For Critically Endangered species seed collections may provide the only suitable backup but in other cases the development of seed orchards for ensuring adequate seed supply will need to be considered more broadly; additional concerns regarding the availability of seed from native vegetation as climates change have also recently been voiced (Mortlock, 2000; Merritt and Dixon, 2011; Broadhurst et al., 2015, 2016b).

The role of translocations in plant species management has significantly increased over the last decade in Australia as threats intensify and become increasingly difficult to manage. The need to establish new viable populations in threat-free habitat presents significant practical and logistical challenges (Monks et al., 2012). Plant translocation guidelines (Vallee et al., 2004) providing the best available techniques and planning templates have been of significant benefit and the recently established NESP Threatened Species Hub Project 4.3 (Table 5) will be focussing on improving plant translocation approaches and species recovery through the development of comprehensive and measurable criteria for success.

4.1. Conservation outcomes

Given the substantial investment in Australian conservation and restoration programs over the 25+ years (Table 4) it is of national interest as to whether we are generally improving the status of species, especially those that are threated. The threat status of 75 listed plants under the EPBC Act were amended between 2002 and 2007 primarily due to improved species knowledge (68%) with some being altered following taxonomic clarification (11%) (Table 6; Department of the Environment Water Heritage and the Arts 2009, 2008). Real change, i.e. change that could be clearly attributed to documented improvement or decline, saw a shift in threat category for 21% of the listed plant taxa with most of these showing ongoing decline with no documented cases of improvement (Department of the Environment Water Heritage and the Arts 2009, 2008). At State-and Territory-levels, 741 listed plant taxa also changed threat categories between 2002 and 2007 with almost two thirds of these being moving to a higher threat level (Table 7; Department of the Environment Water Heritage and the Arts 2009, 2008). The majority of shifts in threat level for State-and Territory-listed species were due to improved knowledge (46%) and taxonomic clarification (36%) (Department of the Environment Water Heritage and the Arts 2009, 2008). Of the 42 species where a shift in threat status was not due to improved knowledge or taxonomic changes, most were in decline apart from two taxa in Victoria and one in Western Australia (Department of the Environment Water Heritage and the Arts 2009, 2008). In addition to this apparent and ongoing decline in threatened plant taxa, annual rates of native vegetation clearing nationally were around 1 M ha between 2000 and 2010 with the condition of much of the remaining native vegetation also deteriorating during this time (State of the Environment, 2011 Committee, 2011). While these figures highlight generally negative trends, the recent development of various recent conservation initiatives outlined in Sections 3 and 4 above indicate that there is a significant commitment to reversing these trends, but we emphasise this will clearly depend on ongoing support not only from governments but also from non-government organisations and most importantly the general public as well.

5. Conservation into the future

As we head towards 2020 we are faced with numerous challenges and opportunities for conserving Australia's unique plant biodiversity. While great advances have been made in understanding ecological and evolutionary processes in the Australian flora, and the diverse array of biological attributes of plant species that influence these processes we are still faced with significant knowledge gaps for ensuring best practice conservation and restoration. For example, sourcing propagules for threatened species reintroductions or ecological restoration, two increasingly important plant conservation approaches for the future, can be controversial with a number of alternative seed sourcing strategies now highlighted (Breed et al., 2013; Prober et al., 2015). Such strategies require an understanding of small population processes and inbreeding depression, local adaptation and outbreeding depression. Although data is available for some Australian species (Broadhurst et al., 2017), it shows that these processes can be complex and idiosyncratic across different plant groups (see Ottewell et al., 2016). New genomic approaches may facilitate answers in some of these areas and new landscape perspectives (Hopper, 2009; Hopper et al., 2016) are providing further insights into alternative flora conservation strategies. While recognising the need for new information, we emphasise that lack of knowledge is not a reason for delaying conservation actions and that adaptive management approaches and learning from management experiments (Westgate et al., 2013) will increasingly provide important opportunities for improved plant conservation outcomes into the future.

Perhaps one of the most important attitudinal changes required to ensure successful ongoing plant conservation initiatives is to educate policy makers, funding agencies and the general public that we are dealing with multi-generational change and outcomes in that we are often setting up the framework for plant recovery with the benefits to be reaped by future, not current, Australians. The success of this, however, requires long term and strategic commitment including pro-active information seeking from multiple sources and stakeholders prior to and during policy development. For example, while key subject-matter experts can be useful, these do not necessarily have the knowledge for successful on-ground delivery of programs. It will also be important for policy-makers and funding agencies developing long term investment strategies to also clearly articulate the risks of not investing or de-investing part way through a program. Successful plant conservation also requires investment to attract, train and retain staff over the long time frames required to build the depth of knowledge that is required to ensure that activities and programs are successful.