Environment Protection and Biodiversity Conservation (Recovery Plan for the Spiny Rice-flower (Pimelea spinescens subsp. spinescens)) Instrument 2024

We jointly make this recovery plan under subsection 269A(3) of the Environment Protection and Biodiversity Conservation Act 1999.

Dated 03/03/2024

Tanya Plibersek

Minister for the Environment and Water (Commonwealth)

Dated 22/01/2024

Steve Dimopoulos

Minister for Environment (Victoria)

Minister for Tourism, Sport and Major Events
Minister for Outdoor Recreation

2.1A  Name

  This instrument is the Environment Protection and Biodiversity Conservation (Recovery Plan for the Spiny Rice-flower (Pimelea spinescens subsp. spinescens)) Instrument 2023.

2.1B  Commencement

  This instrument commences the day after it is registered.

2.1C  Authority

  This instrument is made under subsection 269A(3) of the Environment Protection and Biodiversity Conservation Act 1999.

© Commonwealth of Australia 2024

Ownership of intellectual property rights

Unless otherwise noted, copyright (and any other intellectual property rights) in this publication is owned by the Commonwealth of Australia (referred to as the Commonwealth).

Creative Commons licence

All material in this publication is licensed under a Creative Commons Attribution 4.0 International Licence except content supplied by third parties, logos and the Commonwealth Coat of Arms.

Inquiries about the licence and any use of this document should be emailed to copyright@dcceew.gov.au.

Cataloguing data

This publication (and any material sourced from it) should be attributed as: DCCEEW 2024, National Recovery Plan for the Spiny Rice-flower Pimelea spinescens subspecies spinescens, Department of Climate Change, Energy, the Environment and Water, Canberra, October. CC BY 4.0.

This publication is available at https://www.dcceew.gov.au/about/publications  

Department of Climate Change, Energy, the Environment and Water

GPO Box 3090 Canberra ACT 2601

Telephone 1800 803 772 

Web DCCEEW.gov.au 

Disclaimer

The Australian Government acting through the Department of Climate Change, Energy, the Environment and Water has exercised due care and skill in preparing and compiling the information and data in this publication. Notwithstanding, the Department of Climate Change, Energy, the Environment and Water, its employees and advisers disclaim all liability, including liability for negligence and for any loss, damage, injury, expense or cost incurred by any person as a result of accessing, using or relying on any of the information or data in this publication to the maximum extent permitted by law.

Acknowledgements

This Recovery Plan benefited from the input of many individuals and agencies, especially the following: Debbie Reynolds – Pimelea Conservation Officer, Trust for Nature; Vanessa Craigie – DEECA; Doug Robinson – Trust for Nature; Steve Mueck – Biosis Pty Ltd; Liz James – Royal Botanic Gardens Melbourne; Neville Walsh – Royal Botanic Gardens Melbourne; Megan O’Shea – Victoria University; Paul Foreman – Blue Devil Consulting; Chris Lindorff – Trust for Nature; Deanna Marshall – Trust for Nature; Libby Woodward – Trust for Nature; Ben Thomas – DEECA; Simon Cropper – Botanicus Australia Pty Ltd; and the Pimelea spinescens Recovery Team.

The preparation of this plan was funded by the Commonwealth Government.

Acknowledgement of Country

We acknowledge the Traditional Custodians of Australia and their continuing connection to land and sea, waters, environment and community. We pay our respects to the Traditional Custodians of the lands we live and work on, their culture, and their Elders past and present.

Images credits

Spiny Rice-flower (Pimelea spinescens subsp. spinescens). Photo © Debbie Reynolds (Trust for Nature).

Contents

1 Summary...............................................................1

1.1 Conservation status..................................................1

1.2 Species information..................................................1

1.3 Threats...........................................................1

1.4 Recovery Plan objectives, performance criteria, and actions.....................1

2 General information.......................................................3

2.1 Historical context....................................................3

2.2 Conservation status..................................................3

2.3 Taxonomy.........................................................3

2.4 Community and Cultural Significance.....................................4

2.5 International obligations..............................................5

2.6 Consultation.......................................................5

2.7 Recovery Team.....................................................5

2.8 Affected Stakeholders................................................6

3 Species description and habitat...............................................8

3.1 Biology...........................................................8

3.2 Distribution.......................................................18

3.3 Habitat..........................................................19

3.4 Important populations...............................................20

4 Threats................................................................22

4.1 Historical causes of decline............................................22

4.2 Current threatening processes.........................................22

4.3 Threat matrix......................................................26

5 Guidance for decision makers...............................................29

6 Implementation of the first Recovery Plan......................................31

6.1 Conservation status assessments.......................................31

6.2 Information on habitat...............................................31

6.3 Populations and habitats are protected...................................32

6.4 Threats management................................................33

6.5 Information on key biological traits......................................33

6.6 Population growth rate and viability.....................................34

6.7 Community support.................................................37

7 Recovery Plan...........................................................39

7.1 Performance criteria................................................39

7.2 Actions..........................................................40

7.3 Implementation and evaluation........................................50

7.4 Priorities, timeframes and funding......................................50

7.5 Interactions with existing plans, policies and programs........................53

7.6 Ecological co-benefit................................................54

7.7 Social and economic impacts..........................................56

References.................................................................60

Appendix 1................................................................68

Appendix 2................................................................84

Tables

Table 1 Threats impacting the Spiny Rice-flower......................................27

Table 2 Actions to ensure all Spiny Rice-flower populations and habitat are adequately protected and managed (Strategy 1)......41

Table 3 Actions to address knowledge gaps to better inform adaptive management plans for the Spiny Rice-flower (Strategy 2)......45

Table 4 Actions to support community-based collaboration for the recovery of Spiny Rice-flower (Strategy 3)......48

Table 5 Priorities, actions, timeframes, estimated costs for Spiny Rice-flower recovery within the 5-year reviewa......51

Table 6 Threatened Ecological Communities (TECs) known and likely supporting the Spiny Rice-flower56

Figures

Figure 1 A contrasting phenotype of male (left) and female plant (right), both in flowering stage. Male plants bear more showy flowers than female (see Figure 2 for flower close-up)......9

Figure 2  Flowers of Spiny Rice-flower. Left–female inflorescence, Middle–male inflorescence, Right–hermaphroditic individual bearing seeds and male flowers......10

Figure 3 Conceptual model of the timing of ecological processes including the effect of fire across seasons......11

Figure 4 Spiny Rice-flower hosts various invertebrate species, including insects that are important as its pollination vector......13

Figure 5 Left-Spiny Rice-flower root formation. Right-close up of tap root and underground stem formation of a mature Spiny Rice-flower .....14

Figure 6 Conceptual life-stage model for Spiny Rice-flower...............................16

Figure 7 Prescribed burning at Pioneer Park conducted with Brimbank Council and contractors in attendance......34

Figure 8 Left–The Recovery Team and Mt Korong Eco-Watch Association conducted population monitoring. Right– Supplementary planting and population monitoring at Skipton Common supported by Glenelg Hopkins CMA, Ballarat Environment Network, Pimelea Conservation Trust, Skipton Primary school, Wadawurrung Traditional Owners Aboriginal Corporation, Field Naturalist’s Club Balarat and the Snake Valley CFA Brigade. Spiny Rice-flower recovery is part of the Glenelg Hopkins CMA’s Victorian Volcanic Plain Recovery Project......35

Figure 9 Collecting seeds from multiple populations for supplemental planting. Using seeds from different populations help promote genetic diversity within the often isolated and small remnant populations......36

Figure 10 Spiny Rice-flower translocation. Top–A tree spade mounted on a tractor is used to extract plant to minimise root damage. Bottom–When the recipient site and salvage site are in a close distant, individual plant is transplanted directly after extraction......38

Figure 11 Spiny Rice-flower plant growing in its grasslands habitat..........................55

Maps

Map 1 Spiny Rice-flower Distribution Map..........................................21

1               Summary

1.1                 Conservation status

Pimelea spinescens subsp. spinescens (Spiny Rice-flower) is listed as Critically Endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) effective from 1 May 2003 (TSSC 2003). 

Spiny Rice-flower is listed as Critically Endangered under the Victorian Flora and Fauna Guarantee Act 1988 (FFG Act) (DELWP 2021).

1.2                 Species information

Spiny Rice-flower is a sub-shrub endemic to grasslands and grassy woodlands in western and northern Victoria. In 2022, it is known from more than 325 wild populations containing a total of 70,000 to 90,000 mature individuals. Most populations are restricted to small, isolated grassland habitat on roadsides and railway lines in highly fragmented landscapes (DELWP 2021). The term ‘viable’ is defined within the recovery plan to describe dioecious populations consisting of a minimum of 20 individuals with half of each sex.

1.3                 Threats

Principal threats to Spiny Rice-flower include the loss and fragmentation of habitats through clearing for urban and agricultural development, as well as habitat degradation induced by competition from both native and exotic plants. Fire regimes that cause declines in biodiversity, and prolonged drought have also contributed to the species decline (TSSC 2003; DELWP 2021). Overgrazing by livestock, in some sites, is deemed as a large threat to the subspecies (TSSC 2003).

1.4                 Recovery Plan objectives, performance criteria, and actions
 

Objective

The long-term vision for Spiny Rice-flower recovery is to ensure Spiny Rice-flower can survive, flourish and retain its potential for evolutionary development in the wild through the continuation of threat abatement that maintains and/or enhances viable in situ populations.

This Recovery Plan sets out actions that will ensure significant progress towards achieving this vision.

The objectives over the 10-year life of this Recovery Plan (by 2032) are to:

• Maintain or increase positive trend in the area of occupancy.
• Maintain or increase the number of viable populations (compared to 2021/22 baseline counts).
• Identify, manage and protect all populations of the Spiny Rice-flower from key threats to ensure its persistence.
• Maintain and enhance community and institutional support.

Performance criteria

This Recovery Plan will be deemed successful if, by 2033, all the following criteria have been achieved:

1. The number of known viable 2021/22 populations (both wild and translocated) has been maintained or increased from 2021/22 baseline counts.
2. The number of individuals in each population has been maintained or increased from 2021/22 baseline counts.
3. All known population records are surveyed and accurately and mapped in 2028 and every 5 years thereafter.
4. All known populations are identified, protected and managed to support recovery.
5. The area of occupancy of Spiny Rice-flower has increased through the establishment and protection of new viable populations.
6. The number of populations subject to formal protection measures has increased by at least 10%.
7. Knowledge of Spiny Rice-flower ecology, recruitment and seedling survivorship, genetic variation, and ecological requirements has increased, and this information has been incorporated into the adaptive management plans.
8. Participation in recovery planning and actions by key stakeholders and Traditional Owners has increased.

Recovery actions

The recovery actions are outlined in Table 2, Table 3, and Table 4 (see 7.3 Recovery Actions). The actions are categorised in 3 main strategies:

• Strategy 1: Protecting and managing all populations and habitats.
• Strategy 2: Increasing knowledge of reproductive ecology, population and habitat extent, and disturbance ecology and incorporate this knowledge into adaptive management plans.
• Strategy 3: Increasing community awareness and involvement and support for land managers, community and Traditional Owners to include adaptive habitat management in their work supporting the recovery of Spiny Rice-flower.

2               General information

This document constitutes the National Recovery Plan for the Critically Endangered Spiny Rice-flower (Pimelea spinescens subsp. spinescens). The plan identifies the research and management actions necessary to stop the decline of, and support the recovery of, the species so that its chances of long-term survival in nature are maximised.  This Recovery Plan replaces the previous National Recovery Plan for the Spiny Rice-flower (Carter & Walsh 2006).

2.1                 Historical context

The first Recovery Plan, in effect under the EPBC Act from 16 December 2006, was reviewed in 2012 and in 2020/21 by the Commonwealth Department of Climate Change, Energy, Environment and Water (DCCEEW, previously the Department of Agriculture, Water and the Environment (DAWE)) with the support of the Pimelea spinescens Recovery Team. Considerable achievements have been made during the life of the first Recovery Plan including the identification of numerous newly discovered sites resulting in a higher total population estimate. Meaningful research projects have been completed and have contributed to a better understanding of the species biology and conservation requirements (see 6 Implementation of the first Recovery Plan for details). The review of the first Recovery Plan also concluded that all threats and threatening processes described, continue to adversely affect the species. Consequently, a decision was made that a new Recovery Plan should be developed for Spiny Rice-flower. Responding to the review outcomes, this Recovery Plan builds upon the learnings and successes of the first Recovery Plan.

2.2                 Conservation status

The Spiny Rice-flower is listed as Critically Endangered under the EPBC Act. It is eligible for listing as Critically Endangered under Criterion 2 based on very restricted geographic distribution and severe population fragmentation (TSSC 2003). The Victorian Department of Energy, Environment and Climate Action (DEECA) (formerly Department of Environment, Land, Water and Planning Victoria (DELWP) assessed the Spiny Rice-flower using International Union for Conservation of Nature (IUCN) Red List criteria, as required by the Common Assessment Method (CAM) memorandum of understanding with the Commonwealth government. The assessment found the species eligible for listing as Critically Endangered, due to the extremely severe past population reduction (DELWP 2021), and it subsequently was listed under the Victorian Flora Fauna Guarantee Act 1988 (the FFG Act) as Critically Endangered in Australia, in June 2021.

Previously, at the species level, Pimelea spinescens was listed as threatened under the FFG Act (SAC 1996). Spiny Rice-flower was categorised as Endangered in the 2014 Advisory List of Rare or Threatened Flora (DEPI 2014), which had no critically endangered category.

2.3                 Taxonomy

Conventionally accepted as Pimelea spinescens subsp. spinescens (Rye) (1990), Family: Thymelaeaceae.

Spiny Rice-flower is a conspecific to Pimelea spinescens subsp. pubiflora (Wimmera rice-flower). While spiny rice-flower has smooth and hairless flowers, the flowers of Wimmera rice-flower are covered with soft short hairs (Walsh & Entwisle 1996; DSE 2005a, 2005b; Walsh & Stajsic 2007; TSSC 2009).

A genetic analysis of 459 Spiny Rice-flower samples and 83 Wimmera Rice-flower samples by James & Jordan (2014) confirmed that the two subspecies are genetically distinct and therefore, they should be managed as separate conservation units. Other common names of the species include Plains Rice-flower, and the Prickly Pimelea.

2.4                 Community and Cultural Significance

The cultural significance of the Spiny Rice-flower is currently unknown. Acknowledging First Nations Peoples connection to country and importance of biodiversity, ‘place’, custom and totemic elements of country and species, it is likely that the species has or is associated with some cultural and/or community significance.

Traditional Language Groups

The contemporary distribution of Spiny Rice-flower encompasses the traditional lands of many First Nation groups. These include, but are not necessarily limited to:

Baraba Baraba, Barengi Gadjin, Djab Wurung, Dja Dja Wurung, Djardgurd Wurung, Gadubanud, Gulidjan, Jaadwa, Jadawadjali, Jupagulk, Jardwadjali, Ngurraiillam, Wadawurrung, Wergaia, Woiwurung, Wotjobaluk, Wurundjeri and Yorta Yorta.

Registered Aboriginal Parties

Spiny Rice-flowers distribution is found on lands managed by the following Victorian Registered Aboriginal Parties:

• Eastern Maar Aboriginal Corporation
• Wadawurrung Traditional Owners Aboriginal Corporation
• Wurundjeri Woi Wurrung Cultural Aboriginal Corporation
• Dja Dja Wurrung Clans Aboriginal Corporation
• Berngi Gadjin Land Council Aboriginal Corporation
• Yorta Yorta Nation Aboriginal Corporation
• Taungurung Land and Waters Council Aboriginal Corporation

Parks Victoria Joint Management Agreements

Joint management is a legal agreement between the State and Traditional Owners which empowers Traditional Owners, in partnership with the Victorian Government, to actively participate in the management of land and natural resources within their traditional Country.

The following Registered Aboriginal Parties have joint management arrangements in place. Efforts should be made to engage the following Registered Aboriginal Parties that have joint management arrangements in place:

• Yorta Yorta Nation Aboriginal Corporation – Yorta Yorta Traditional Owner Land Management Agreement 2010
• Dja Dja Wurrung Clans Aboriginal Corporation - Dja Dja Wurrung Recognition and Settlement Agreement 2013
• Taungurung Land and Waters Council Aboriginal Corporation – Taungurung Recognition and Settlement Agreement 2018

2.5                 International obligations

Australia is a signatory to the International Ramsar Convention (1971) to halt the worldwide loss of wetlands and to conserve, through wise use and management, those that remain. Spiny Rice-flower is recorded from sites where two Wetlands of International Importance are listed under the Ramsar Convention (Australian Ramsar Wetlands 2022) and thus fall under the international obligations of the treaty:

• Port Phillip Bay (western shoreline) and Bellarine Peninsula (the western water treatment plant at Werribee, Lake Borrie wetlands), and
• Western District Lakes (numerous individuals along roadsides within the Ramsar area).

Australia is also a Party to the international Convention on Biological Diversity (CBD) (1982) to conserve biological diversity and promote sustainable development. The Spiny Rice-flower occurs in areas where urban development is expanding due to rapid human population growth. A sustainable development approach for the species is required to meet the international obligations of this treaty.

The species is not listed under the appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

2.6                 Consultation

During the drafting process DCCEEW worked closely with key stakeholders. Consultation on the draft Recovery Plan brought together ideas from species and land management experts to outline the current status of knowledge, information gaps and potential management options.

During the life of the first Recovery Plan, the Pimelea spinescens Recovery Team reached out to a representative of the Wurundjeri Traditional Owners to provide updates and progress on recovery actions including the preparation of this Recovery Plan. The Recovery Team also has reached out to the representative from Wadawurrung Traditional Owners Aboriginal Corporation to provide their insights on the draft Recovery Plan.

2.7                 Recovery Team

Recovery teams provide advice and assist in coordinating the implementation of Recovery Plans. The Pimelea spinescens Recovery Team, originally set up as the Pimelea working group in 2005, was formalised in 2007. The Pimelea spinescens Recovery Team is a group working towards achieving better conservation and management outcomes for Pimelea spinescens including Spiny Rice-flower. The current Recovery Team comprises representation from DEECA, Royal Botanic Gardens Victoria, Parks Victoria (PV), Department of Transport and Planning (formerly called VicRoads), Trust for Nature (TfN), 27 local governments, six Catchment Management Authorities (CMAs), the Country Fire Authority (CFA), environmental and private sector consultancies, Landcare groups and researchers (universities and botanic gardens). The Pimelea spinescens Recovery Team is mainly supported by the Pimelea Conservation Trust (PCT) through TfN. PCT administers the funds in accordance with the Conservation Agreement between the Commonwealth and Multiplex Developments No: 8 Pty Ltd with TfN acting as Trustee (Trust for Nature 2014).

The Pimelea spinescens Recovery Team coordinated the implementation of the first National Recovery Plan of Spiny Rice-flower and will continue its role in providing advice and coordinating the implementation of this Recovery Plan.

2.8                 Affected Stakeholders

Populations of Spiny Rice-flower occur on land owned or managed by government authorities, organisations and private individuals. Conservation of Spiny Rice-flower is dependent upon cooperation through a range of agencies and conservation groups who either manage land or undertake conservation activities, as well as Traditional Owners and their representatives such as, Registered Aboriginal Parties, Indigenous ranger groups, Indigenous land councils, and Indigenous community groups. All recovery actions are to be undertaken in a manner that respects the cultural practices of Traditional Owners. Planned recovery actions include increased support and participation in recovery planning and actions by key stakeholders, including Traditional Owners. Affected stakeholders and potential conservation partners include but are not limited to the following:

3               Species description and habitat

3.1                 Biology

Description

Spiny Rice-flower is a perennial, slow-growing sub-dioecious shrub (DSE 2008; Cropper 2004). It has dull green and hairless oval leaves 2–10 mm long and 1–3 mm wide (Carter & Walsh 2006). New growth is soft, smooth, and almost herbaceous which develops into short spiny (spinescent) divaricate branches and stems. The stem tips become hard, leafless and form a spinescent tip as the plant gets older (Walsh & Entwisle 1996). The flowers are produced in a terminal compact head (inflorescence). The inflorescences are clusters of 6–12 small, unisexual (rarely bisexual) flowers which are hairless and cream in colour. Inflorescences are subtended by four leaf-like bracts 3–7 mm long and 1.5–4 mm wide. The 2–3 mm long flowers are glabrous (hairless) and have four rounded, petal-like lobes (Carter & Walsh 2006). Female flowers are slightly smaller than male flowers and have two small non-functional anthers while the male flowers bear anthers with bright orange pollen. The fruit is ovoid or ellipsoid, 2–3 mm long, and has a thin, initially fleshy layer around a slightly woody 'stone' that encloses the single, oily seed (Walsh & Entwisle 1996; Carter & Walsh 2006).

The majority of individuals observed in the wild are sub-dioceous, although, hermaphroditic (bisexual) individuals are also present (Foreman 2012; Reynolds 2013). Across populations observed, the female phenotype appears to be more abundant than male or hermaphroditic individuals (Dear 2019). A male individual bears all male flowers or predominantly male flowers and conversely, a female individual bears all or predominantly female flowers and there is a clear phenotypic distinction between flowering male and female individuals (Figure 1). An individual is considered hermaphroditic when it produces a relatively balanced ratio of male and female flowers. In a hermaphroditic individual, each inflorescence is exclusive to either male or female flowers (Figure 2) (Carter & Walsh 2006; Foreman 2012; Reynolds 2013). A hermaphrodite individual could change its presentation of flowers over the season, but it will always have both flower types present (Reynolds 2013). Further investigation on how changes of sex expression may affect maintenance of long-term population viability is required to assist with species recovery planning, such as population monitoring and translocation strategy.

Life cycle

Flowering occurs over winter from April through to August (Figure 3), unlike the majority of other grassland plants in this ecosystem (Entwisle 1996; Walsh & Entwisle 1996). Germination in situ has been observed between May until November and appears to be stimulated by cool winter and spring temperatures (Foreman 2011; Reynolds 2013), suggesting physiological dormancy. When seeds germinate, the seedlings stay as non-reproductive recruits for one year and will enter the juvenile stage after the second year. Some juvenile plants may start to reproduce but at much lower rates than adult plants. Individuals may remain as juveniles until approximately five years of age before moving on to the adult stage, where reproduction and survival is higher (Figure 3; Regan et al. 2021). Individuals remain reproductively active until they senesce (Mueck 2000; Carter & Walsh 2006). Spiny Rice-flower is a long-lived species with a lifespan estimated up to 100 years (Mueck 2000 cited in Carter & Walsh 2006; Regan et al. 2021). The generation time is estimated to vary between 50 to 80 years (Mueck 2000; Foreman 2005; DELWP 2021).

Figure 1 A contrasting phenotype of male (left) and female plant (right), both in flowering stage. Male plants bear more showy flowers than female (see Figure 2 for flower close-up).

Photo © Debbie Reynolds

Figure 2  Flowers of Spiny Rice-flower. Left–female inflorescence, Middle–male inflorescence, Right–hermaphroditic individual bearing seeds and male flowers.

Photo © Debbie Reynolds

Figure 3 Conceptual model of the timing of ecological processes including the effect of fire across seasons.

Source: Regan et al. (2021)

Reproduction

Pollination

As the Spiny Rice-flower is predominantly an outcrossing species (DEWHA 2009a; James 2012) there is a need to transport pollen between male and female plants, making it particularly vulnerable to a lack of pollinators (Reynolds 2013). Insect pollinators such as introduced honeybees, lycaenid butterflies (Foreman 2005), beetles (Cropper 2004), Dipteran and Hymenopteran flies (Cropper 2009) have been reported to visit Spiny Rice-flower (Foreman 2012) (Figure 4). These insect pollinators have small home ranges and are only able carry pollen over short distances, and thus effective pollination and seed production are affected by the spatial distribution of the individuals and populations, as well as the size and density of the population (Reynolds 2013). Genetic analysis suggests that most seeds result from outcrossing by insect pollinators (James & Jordan 2014) but viable seeds are known to be produced through selfing (pollen from male flowers on the plant fertilising female flowers on the same plant) in hermaphroditic plants through geitonogamy, indicating that there is a degree of self-compatibility in the breeding system (TSSC 2016).

Seed and germination traits

Seed fecundity and viability levels are relatively high and stable (Reynolds 2013). Seed production or fecundity, expressed as number of seeds per stem, is generally dependent on temperature and rainfall. Rainfall was relatively high in 2010, effectively ending a 13-year period of drought, and this was reflected in a lower seed fecundity across Spiny Rice-flower female individuals on the Victoria Volcanic Plains (4–32 seeds per stem in 2010 compared to 15–247 seeds per stem in 2009; Reynolds 2013). Plants are likely to have suffered from pollination limitation due to lower rates of insect pollinator activity during such a wet year.

Seed viability, an indication of maternal plant’s ability to access resources, is improved by frequent biomass reduction (for example through burning) of the surrounding vegetation (Reynolds 2013). Spiny Rice-flower seeds possess a ‘non-deep physiological dormancy’ sensu Baskin & Baskin (2004). A period of dry storage followed by at least a month of cold stratification was found to alleviate seed dormancy (Reynolds 2013). Seed germination also positively responds to stimulation by gibberellic acid. Spiny Rice-flower germination follows a staggered germination syndrome (germination is not synchronous, and thus seedlings are produced as different multiple cohorts over time), even under optimal conditions (Reynolds 2013).

While the seed is oily and buoyant and can disperse via seasonal flood events, the seed has no obvious adaptation for long distance dispersal, and germinants (seedlings) commonly cluster close to female or bisexual plants (Foreman 2005, 2011; James & Jordan 2014). Circumstantial observations have found seedlings in a translocated soil plug even in the complete absence of the flowering plant or recent seed introduction. This implies that a persistent soil seed bank exists (Reynolds 2013). Regan et al. (2021) suggested that the Spiny Rice-flower seed bank can remain in the soil while maintaining its viability for approximately 6 years (Figure 5).

Given the continuing pressure on native species habitat and noting the lack of opportunities for successful in situ recruitment, ex situ seed conservation is a strategic approach to safeguard native plant species (Martyn Yenson et al. 2021) and would support the recovery of the Spiny Rice-flower when seed is actively used in restoration or translocation programs. In support of ex situ seed conservation, a seed collection protocol for Spiny Rice-flower has been developed by the Pimelea spinescens Recovery Team (2018). Further, noting that seed supply is key for Spiny Rice-flower translocations as well as grassland habitat restoration, further research should include aspects of securing and use of a genetically diverse seed supply.  

Figure 4 Spiny Rice-flower hosts various invertebrate species, including insects that are important as its pollination vector.

Photo © Elspeth Swan (left) and Debbie Reynolds (right)

Recruitment in situ

The majority of Spiny Rice-flower populations consist of mainly mature individuals (McCaw 2014, 2020), which may indicate an obstacle to or failure of recruitment (Mueck 2000; Reynolds 2013). Spiny Rice-flower has been observed to have episodic germination and infrequent successful recruitment, i.e., seedlings are numerous at times but survival rate through summer are extremely low (Reynolds 2013; DELWP 2021). Across multiple sites on the Victoria Volcanic Plains, for example, the recruitment level measured by number of seedlings surviving the first summer was only 14% (Reynolds 2013). Seed production and seedling establishment appears to be inhibited by both drought conditions and higher than average rainfall (Foreman 2011, 2012). Drought limits the reproductive capacity of mature plants, while during wet years, pollinator activity may be limited leading to lower seed production. In addition, high rainfall that leads to floods can adversely affect seedling survival. Understanding the key environmental drivers for successful Spiny Rice-flower recruitment is therefore crucial to inform its management and recovery (Reynolds 2013).

Although the Spiny Rice-flower has a deep (up to 1.5 m) taproot that can form underground stems and facilitate resprouting after biomass removal events (e.g., fire), it does not have the capacity to reproduce vegetatively (Mueck 2000; James & Jordan 2014).

Figure 5 Left-Spiny Rice-flower root formation. Right- close up of tap root and underground stem formation of a mature Spiny Rice-flower.Photo © Debbie Reynolds

Fire ecology

Exposure to differences in fire frequency may contribute to the morphological differentiation between populations. The ‘northern form’ populations (i.e. those north of the Great Dividing Range) consist of more vigorous adult plants (that have not been exposed to burning) than ‘southern form’ that are regularly affected by burning. Northern populations have been observed to have almost certainly declined more dramatically than the southern, basalt plain populations (DSE 2008; Appendix 1), indicating that appropriate fire regimes is paramount to support recruitment and population persistence.

Spiny Rice-flower germination and seedling establishment are substantially impeded when inter-tussock space diminishes (Morgan 1998; Lunt & Morgan 2002). Fire opens up the vegetation and creates bare ground and gaps, providing an opportunity for the Spiny Rice-flower to recruit from the soil seed bank. Fire also creates inter-tussock spaces important for seedlings to establish and mediates the coexistence of other native grassland species by interrupting the exclusion of competitors (DAWE 2022). Low competition induced by fire events combined with good seasonal rainfall may promote successful recruitment of Spiny Rice-flower (Mueck 2000; Carter & Walsh 2006; DELWP 2021). Despite the availability of bare ground, recruitment of the Spiny Rice-flower post-fire can be low, particularly following hot summers and low rainfall (Mueck 2000).

While fire can help to reduce competing biomass and promote germination, it can increase individual mortality across various life stages (Figure 3; Regan et al. 2021). If fire occurs prior to or during the flowering and seed production season, it removes the reproductive output for that year and consequently reduces the potential for seed accumulation in the soil (Regan et al. 2021). Burning over the summer months has been suggested to have minimal damage to or mortality of adult plants. Adult individuals are, however, quite tolerant of fire due to the large taproot which can readily resprout after fire (Mueck 2000; Carter & Walsh 2006).

The Recovery Team guidelines for burning (Pimelea spinescens Recovery Team 2017) suggested that biomass reduction should occur at an interval of at least once every three years. It is important to note though, that in areas of high productivity or during wet years, it may be necessary to burn more frequently, and accordingly, 4 to 5 years or even longer burning intervals may be sufficient for lower productivity sites. Burning from late spring (November) through summer or into early autumn (April) is recommended. Further, in areas where the species is known to occur and fire control lines are required, a native vegetation survey conducted by a qualified botanist must be undertaken at the appropriate time before site preparation commences (Reynolds 2015).

Figure 6 Conceptual life-stage model for Spiny Rice-flower

Source: Regan et al. 2021

Genetics

Genetic diversity and fragmentation

The genetic diversity of Spiny-rice flower has not declined as a result of habitat loss and fragmentation. The retention of genetic diversity may be the result of plant longevity, where older plants reflect the gene flow of previously connected, but now isolated populations.  This fragmentation now creates the risk of loss of genetic diversity, as these individuals die out, and fewer individuals contribute to future generations within a population (James & Jordan 2014). Outcrossing enforced by sub-dioecy limits the loss of genetic diversity per generation (Duminil et al. 2009) and is possibly instrumental in maintaining the genetic diversity for Spiny Rice-flower. A relatively high population level genetic diversity is consistent with the hypothesis that in the past populations were interconnected and interbreeding among populations was conspicuous (James & Jordan 2014). The longevity of individual plants, their ability to reproduce for many years and the presence of soil seed banks may contribute to the maintenance of genetic diversity and could buffer deleterious effects of random genetic drift caused by fragmentation and disturbance (Schulz et al. 2018).

Whilst intrinsic factors such as long individual lifespan and soil seed banks may facilitate preservation of a species’ genetic diversity (Long et al. 2015; Broadhurst et al. 2017), a recovery action that seeks to ensure the maintenance of genetic diversity into the future is essential.  The success of adaptation to changing environments, such as climate change, is underpinned by genetic variation and consequently, reduced genetic diversity may limit the species’ evolutionary potential (Jump & Penuelas 2005; Anderson et al. 2011; Hoffmann & Sgro 2011). Strikingly, smaller populations (300–600 individuals) of Spiny Rice-flower contain levels of genetic diversity similar to larger populations (>1000 individuals), thus stressing the potential importance of smaller populations in the environmental resilience of Spiny Rice-flower (James & Jordan 2014).

Despite the presence of significant genetic diversity, the persistence of Spiny Rice-flower is likely to be compromised if further fragmentation occurs (James & Jordan 2014). Of particular concern is the small size of the majority of populations. Small and disconnected populations are at greater risk of extinction than large populations due to both physical damage and genetic decline. Reduced connectivity may increase inbreeding with detrimental consequences for outcrossing  species , and as surrounding habitat is lost, new populations are unlikely to establish (Ellstrand & Elam 1993; Lande 1993; Honnay & Jacquemyn 2007).

Investigation of possible mechanisms for dispersal away from parent plants and populations would assist in the design of vegetation corridors to increase geneflow in areas where populations are surrounded by unsuitable habitat (James & Jordan 2014). Further analysis of genetic variation between and within sites and correlating this with biogeographic variables and investigating the prevalence and importance of vector-driven outcrossing is required.

Sourcing genetic materials for recovery action

Spiny Rice-flower genetic diversity occurs across a cline from the Melbourne area westwards and then to the north and northeast (James & Jordan 2014), rather than as discrete suite of genetic ‘groups’ correlated with distinct geographic regions (Foreman 2005, 2012). Populations located within a 25–35 km radius among each other are generally more genetically similar than populations further apart (James & Jordan 2014).

The high genetic diversity of Spiny Rice-flower may permit adaptation to novel conditions, and genetic mixing between populations may enhance their adaptive opportunities. For Spiny Rice-flower translocation and conservation purposes, seeds should be collected from a number of different plants from each source population. Mixing genetic material within, but not between, northern and southern populations may provide a benefit for its long-term viability. The proportion of genetic material should reflect the relative distances between source locations (Broadhurst et al. 2008; James & Jordan 2014). Therefore, consideration of habitat (source-recipient) matching should underpin the sourcing of planting material for translocations (James & Jordan 2014). Populations located in the Victorian Riverina bioregion, notably, have unique genotypes different to the other populations and may have different levels of ploidy, and therefore, it is recommended that translocation within the Victorian Riverina only use genetic materials from this bioregion. Genetic material from multiple populations (except for the Riverina bioregion) can be combined for reintroduction or for augmenting populations with a relatively low level of genetic variation. For populations not at risk of inbreeding, the recommendation is to source genetic materials from within 60 km of the recipient site. This recommendation may be subject to review under further consideration of potential climate change impacts.

Assessment of habitat matching and climate-provenancing, and well-designed experimental studies, should be undertaken to ascertain how the long-term persistence of the Spiny Rice-flower populations may be affected by changing environmental conditions. Evolutionary genetics is an important consideration in translocation strategies (Weeks et al. 2011), and therefore it is important quantify the genetic and phenotypic traits and their plasticity, including its intraspecific trait variation, such as seed and germination traits, in the assessment for the adaptive capacity of Spiny Rice-flower.

3.2                 Distribution

The Spiny Rice-flower is endemic to Victoria. It occurs on basalt-derived soils west of Melbourne across the central Victorian Volcanic Plains and on alluvial soils across west and central Victoria (Map 1; Walsh & Entwisle 1996; DSE 2008; DELWP 2021). The species’ extent of occurrence (based on 2 x 2 km grids around reliable records) is estimated to be 1,152 km² based on post-1970 records in the Victorian Biodiversity Atlas. Population size is estimated as 70,000 to 90,000 mature individuals, distributed in approximately 275 wild populations (DELWP 2021). The most recent population survey that is currently ongoing discovered that that there are about 325 known populations of Spiny Rice-flower (in Appendix 1).

The Spiny Rice-flower populations are predominantly located in the Victorian Volcanic Plains, Victorian Midlands and Victorian Riverina IBRA (Interim Biogeographic Regionalisation for Australia) Bioregions (DEH 2000). Other populations are also known to occur in the Wimmera Plains, Central Victorian Uplands, Goldfields, and Dundas Tableland bioregions. Based on the modelled distribution, Spiny Rice-flower is known to occur within the following Natural Resource Management regions: Corangamite, Glenelg Hopkins, Port Phillip and Western Port, North Central, Goulburn Broken and Wimmera.

Spiny Rice-flower populations mostly occur in tiny patches of remnant habitat such as on roadsides and rail easements (Carter & Walsh 2006; DELWP 2021) that support small to medium size populations (<500 individuals), although a few large populations (consisting of >1000 individuals) are also known. The recent specific needs elicitation process conducted by DEWLP has found that the persistence of the species is greatest at sites with a large population, and reduced persistence is directly correlated to decreasing population sizes. Management efforts have also been found to be more effective within larger populations. Populations of the Spiny Rice-flower that are particularly large, ecologically distinct, or of particular importance include the following:

• Population on the Mt Mercer – Shelford Road in Golden Plains Shire. This site contains ~20,000 plants and is considered as the largest known population of Spiny Rice-flower.
• Population on McLeods Road in Wimmera. Another roadside population that is very large; contains >11,000 plants.
• Browns Waterholes Bridge Rail Reserve (~5500 plants), and Poorneet West Rail Reserve (~6000 plants) – they are among the largest of rail reserve populations.
• Blacks Creek Nature Conservation Reserve. This is one of the largest grassland reserves on the Victorian Volcanic Plain (234 ha) with a population size of >500 plants.
• Lake Borrie Spit, Western Treatment Plant: contains ~250 plants, and is a secure Ramsar site which is actively managed for its biodiversity values by Melbourne Water.
• Deep Lead Flora Reserve supports relatively small population in high-quality vegetation. The site (dominated by swampy Yellow Gum (Eucalyptus leucoxylon) forest) is atypical for Spiny Rice-flower and is at or near the western limit of its range and thus considered important population despite the small population size.
• Truganina Cemetery: contains >300 plants and is an intact small native grassland within an active cemetery. A Public Authority Management Agreement (PAMA) exists between the Cemetery Trust and DEECA.
• A small parcel of private land between the rail reserve and Hamilton Highway, east of Cressy supports ~1,900 plants, and private land at Creswick-Newstead Road, ~2000 plants.
• Skipton Common (~1,416 plants). The population has become a focal area for the local community through school activities and the Ballarat Environmental Network management.

3.3                 Habitat

Spiny Rice-flower prefers intact grassland remnants, lowland grasslands, grassy woodlands and open shrublands (DSE 2008, 2005b; Brennan & Herwerth 2005; Barnes et al. 2006; Carter & Walsh 2006; Foreman 2011, 2012). The common ground layers of the habitat consist of Themeda triandra (Kangaroo Grass), Rytidosperma spp. (wallaby grasses) and Austrostipa spp. (spear grasses) (Carter & Walsh 2006; DEWHA 2009). Other species associated with Spiny Rice-flower include Acaena echinata (Sheep’s Burr), Calocephalus citreus (Lemon Beauty-heads), Chrysocephalum apiculatum (Common Everlasting), Eryngium ovinum (Blue Devil), Plantago varia (Variable Plantain), Ptilotus erubescens (Hairy Tails), Schoenus apogon (Common Bog-sedge) and Goodenia paradoxa (Spur Goodenia) (Carter & Walsh 2006). Extant populations of Spiny Rice-flower are observed to persist in a wide range of grassland conditions, including disturbed and degraded patches such as railway lines and roadsides.

Spiny Rice-flower populations are predominantly associated with the Natural Temperate Grassland of the Victorian Volcanic Plain, and the Natural Grasslands of the Murray Valley Plains threatened ecological communities (TECs) (TSSC 2016). They also occur in several other TECs listed under the EPBC Act (Foreman 2005, 2012) including the Eucalyptus leucoxylon (Yellow Gum) and E. microcarpa (Grey Box) grassy woodland TEC in the Goldfields region, and Allocasuarina luehmannii (Buloke) open grassy woodland in the Wimmera region (Table 6).

The populations are established on heavy grey-black clay loam basalt-derived soils in south-western Victoria (southern populations) and red clay complex sedimentary soils in north-central Victoria (northern populations) (DEWHA 2009; TSSC 2016). Populations are often found on a flat topography but may also occur on slight rises or in slight depressions and some populations are exposed to temporary inundation (Foreman 2012).

Habitat critical

Habitat critical to the survival of a species or ecological community refers to the areas that are necessary for activities such as breeding or dispersal; long-term maintenance of the species including the maintenance of pollinators; areas important to maintain genetic diversity and long-term evolutionary development; or necessary for the reintroduction of populations or recovery of the species. All known habitat for wild and translocated populations is critical to the survival of Spiny Rice-flower (see 3.3 Habitat). This includes all grasslands, grassy woodlands and open shrub-lands occupied by all known extant populations, areas of similar habitat surrounding and linking known populations, habitat at sites where plants were known to occur until recently, and additional occurrences of similar habitat that may contain undiscovered populations of the species or be suitable for future translocations.

No Critical Habitat as defined under section 207A of the EPBC Act has been identified or included in the Register of Critical Habitat

3.4                 Important populations

An important population is a population that is necessary for a species’ long-term survival and recovery. Key source populations necessary for breeding or dispersal, or maintaining genetic diversity, and/or populations that are near the limit of the species range are also considered important populations. Given the conservation status, generally small population size, and threats that are present across species range, all known populations (Appendix 1) are considered important populations.

Map 1 Spiny Rice-flower Distribution Map

4               Threats

4.1                 Historical causes of decline

The Spiny Rice-flower’s current distribution across multiple linear reserves indicates that it was extremely widespread prior to European settlement (Carter & Walsh 2006; DELWP 2021). Since European settlement, Spiny Rice-flower has undergone widespread and catastrophic decline in range and abundance. The population reduction over the past 150 to 240 years is estimated to be 90–99% (DELWP 2021), primarily as a result of the loss of lowland grassland habitats to settlement and agriculture.

4.2                 Current threatening processes

The primary threats to the Spiny Rice-flower are land clearing and habitat degradation (TSSC 2016; DELWP 2021). Habitat fragmentation is predominantly a result of land clearance for urban development, agriculture, settlement, and industry (DELWP 2021). The majority of populations exist in areas that are not managed appropriately or are subject to ongoing changing land use and development (Foreman 2012; Reynolds 2013; TSSC 2016). Sites situated on public land (roadsides, rail reserves and cemeteries) are progressively being lost or disturbed. Populations on private property are vulnerable to change in land use, as many of these private sites are being developed and pasture grasslands are increasingly being cropped. As most populations are small and fragmented, their long-term viability can only be sustained with intensive site management supported by ex situ conservation actions where appropriate. The priority Recovery Actions (Table 5) include population monitoring and a state-wide census to inform prioritisation of resource allocation for recovery actions.

The main threats to Spiny Rice-flower are further discussed below.

Habitat loss and fragmentation

Habitat loss and fragmentation due to anthropogenic pressures continues to be the primary threat to the Spiny Rice-flower. The grassland habitats of Spiny Rice-flower have been extensively cleared or modified for agriculture, urban and industrial developments (Reynolds 2019; DELWP 2021). The development around Melbourne urban area led to a massive pressure for grassland habitats and Spiny Rice-flower. The Melbourne Strategic Assessment (MSA), developed to regulate development impacts on certain threatened species, including Spiny Rice-flower, around these urban corridors. An audit by the Victorian Auditor General’s Office (VAGO), found that only 5% (72 ha from the targeted 1,138 ha) of highest-priority habitats for Spiny Rice-flower within the Victorian Volcanic Plain Bioregion has been able to be protected under MSA (VAGO 2020). While the level of development pressure on Melbourne’s outer western fringe suggests the risk of destruction is greatest in this area (VAGO 2020), the risk of loss is also high throughout the species’ range because the majority of populations are small and unprotected.

Roadsides and rail reserves support some of the most important habitats of Spiny Rice-flower, particularly within the Natural Temperate Grasslands of the Victorian Volcanic Plain (Carland & Kennedy 2010). These populations are at great risk of individual loss from any maintenance works such as slashing, grading, clearing, herbicide application, road widening and soil compaction by vehicle movement (Carter & Walsh 2006; Foreman 2012). Incremental losses of individual plants, without replacement, can rapidly lead to extirpation especially for these small and often isolated populations (Ramalho et al. 2014). Spiny Rice-flower populations located along narrow linear road or rail reserves are also subject to high levels of edge effects and therefore have a greater probability of degradation over time (DSE 2008).

Reduced connectivity that limits gene-flow between sites is another major threat following on from habitat loss and fragmentation. Small populations can retain valuable genetic variation and remain biologically important if close enough to be connected by gene-flow. However, as the distance between populations is greater than its known pollinators’ travel capacity, the genetic integrity of Spiny Rice-flower may be at risk of inbreeding depression (Markert et al. 2010; James & Jordan 2014).

Despite the improvement in our understanding of distribution and occurrence of Spiny Rice-flower, the statement in the initial advice from the Threatened Species Scientific Committee (TSSC 2003) to the then Minister is still applicable: “Based on the rate of decline of grassland habitat since the 1980s, it is estimated that the population size of Pimelea has declined by as much as 30% over the past 20 years”. This conclusion is supported by a study in 2018 which revisited 14 sites which were first surveyed in 2009. The study found that eight of the 14 sites were decreasing in size with mature plants dying and seedlings rare (Reynolds 2019).

Habitat loss associated with land tenure

About 52% of the population (approximately 84% of total individuals; Appendix 1) are located within unreserved public land consisting of roadside and railway corridors which are subject to continuous pressures from traffic disturbances, compaction from vehicles, and management activities (slashing, mowing, runoff of toxicants). Approximately 20% is situated on private land, with 15% of the total population occurring within existing conservation reserves and 10% is in utility sites owned by Melbourne Water, Local Government and other agencies (Appendix 1). Several very large populations (>1,000 individuals each) occur on private properties where the tenure is unsecured, and on other public land not reserved for conservation (Carter & Walsh 2006; Foreman 2012; TSSC 2016; Appendix 1). Regardless the tenure types, the majority of sites support extremely low numbers of individuals (< 10 plants) that are unlikely to survive without intensive management intervention such as prescribed burning and weed control (Appendix 1).

Managing private land is important to ensure that Spiny Rice-flower grassland habitats do not further degrade before formal acquisition or protection. In Victoria, native vegetation clearing controls apply, however there are exemptions for permitted clearing which may result in loss of Spiny Rice-flower plants or populations. Furthermore, planning solutions such as the Melbourne Strategic Assessment (DSE 2009) have not achieved the intended conservation objectives (VAGO, 2020) for species such as the Spiny Rice-flower and its habitat. Grassland habitat on public land has not been managed to protect or enhance its biodiversity assets despite government assurance (VAGO 2020). A strategic program to enact covenants, voluntary acquisitions and implement long-term and appropriate management is critical to avoid the loss of Spiny Rice-flower populations and habitat on private property. This program has been initiated by the Pimelea spinescens Recovery Team.

Climate change

Spiny Rice-flower individuals, particularly seedlings, are sensitive to prolonged drought. Populations have been observed to significantly decline over relatively short periods of time when subject drought (Foreman 2012; McCaw 2020). Rainfall in southeast Australia has been declining in recent decades and is projected to decline further, especially in the cooler months of the year (CSIRO & Bureau of Meteorology 2020). Climate change is anticipated to further threaten Spiny Rice-flower populations, but the mechanisms by which persistence may be impacted can only be inferred from the ecology of the species and require further research. For instance, the plant relies on cool autumns and winters to trigger flowering and seed production, and thus, warm nights in autumn may lead to reduced reproduction. Increasingly hot summers will also lead to reduced survival of seedlings, likely from the effect of hot and dry wind and high temperature at night (DELWP 2021). Further, the duration, frequency and intensity of drought periods may increase across the range and will likely have cascading impacts across the life stages of the species including flowering, seed production and recruitment (Hoffman et al. 2010, 2019; Satyanti 2021). Flowering periods may be affected by changing climatic signals, resulting in phenological shifts that may also decouple plant-pollinator interactions (Hoffman et al. 2019). This may ultimately reduce the reproductive capacity of obligate outcrossing taxa, like the Spiny Rice-flower.

Climate change can also drive changes in existing fire regimes, with more frequent and intense fires projected alongside shorter windows of opportunity for individuals to reach maturity before fire recurs (immaturity risk; Westerling et al. 2011). Given that fire severity and frequency are both predicted to continue to increase under climate change (van Oldenborgh et al. 2020), some species may be driven to extinction in coming decades as fire-free periods are reduced (Enright et al. 2015). This has potential ramifications for communities that are adapted to and shaped by fire events including grasslands of the Victoria Volcanic Plain, and species associated with them, including Spiny Rice-flower. 

Fire regimes that cause declines in biodiversity

Grassland communities require regular biomass reduction to maintain their habitat structure and species richness (Morgan 1995; DAWE 2022). Historically, biomass reduction has been facilitated by natural fire and low intensity grazing from native herbivores (Lunt & Morgan 1999 cited in DSE 2008). Fire regimes that cause biodiversity decline in temperate grassland communities on the Victoria Volcanic Plain, where the Spiny Rice-flower predominantly occurs, have been identified as low fire frequency and fire-competition interaction (DAWE 2022). Low fire frequency (long intervals between fires) cause decline in these populations directly by failing to trigger essential life-history cues to habitat suitability, or through interactions with other threats such as fragmentation (DEWHA 2009; TSSC 2016; DAWE 2022). Traits sensitive to low fire frequency include a combination of short-lived seed banks and low seed-dispersal range (DAWE 2022); these traits are possessed by Spiny Rice-flower (Foreman 2005, 2011; Reynolds 2013; James & Jordan 2014; TSSC 2016). For natural temperate grassland communities, fire-competition interactions may pose a threat when fire accelerates invasion processes by creating gaps for the entry of invasive competitor or when it promotes the establishment of high-density dominant native species that outcompete other native inhabitants and eventually transform the characterising structure and composition of the communities (DAWE 2022). Too frequent fire may threaten invertebrate populations including those that pollinate Spiny Rice-flower.

For Spiny Rice-flower and many grassland species, fire can support their persistence. Reducing biomass through planned burning promotes germination and seedling establishment of Spiny Rice-flower, although it can also lead to increased mortality of existing plants or removal of reproductive output (soil seed bank) if it is undertaken during flowering seasons (Regan et al. 2021).

Weeds

The invasion of exotic plants which leads to habitat degradation and competitive exclusion Spiny Rice-flower is one of the key threats observed across sites. The risk is greatest in the smaller, more isolated and heavily disturbed sites where populations will almost certainly be lost without active weed and biomass management (Foreman 2012).

In the absence of biomass reduction, the dominant perennial tussock grasses tend to out-compete and suppress the less competitive smaller plants, such as Spiny Rice-flower. Successive years without appropriate biomass reduction will result in loss of many herb species and senescence and death of kangaroo grass tussocks (Lunt & Morgan 1999 cited in DSE 2008). Open spaces may then be colonised by opportunistic perennial weed such as canary-grass (Phalaris aquatica), flax-leaf broom (Genista linifolia) and tall wheatgrass (Lophopyrum ponticum), which are known to be particularly strong competitors to Spiny Rice-flower (DSE 2008). Other weed species including sheep sorrel (Acetosella vulgaris), common bent (Agrostis capillaris), cock’s foot (Dactylis glomerata), and perennial ryegrass (Lolium perenne) are also detrimental to spiny rice-flower plants (Foreman 2012).

Grazing by domestic stock and native herbivores

Most populations are threatened by introduced herbivores including European rabbits (Oryctolagus cuniculus) and hares (Lepus europaeus), while populations on private land have the additional pressure of grazing by domestic stock (Carter & Walsh 2006). Effective site management has improved the size of populations−for example at Lake Borrie, plant numbers increased by 33% between 2006 and 2008 following the elimination of rabbits by fencing and weed eradication by spot spraying and routine burning (Cropper 2009; TSSC 2016).

Overgrazing can adversely impact grassland habitats by disrupting habitat structure and increasing nutrient loads and potential disturbance to seedlings. Light grazing regimes (low stocking levels and rotational systems) may provide benefits for spiny rice-flower plants by maintaining an open habitat and by reducing competition from weeds but at a slower rate compared to fire (Foreman 2012). Anecdotal observations suggest that light grazing by native mammals and domestic stock is not detrimental to plants, and may provide benefits through a reduction in surrounding biomass. The digging action of marsupials such as bandicoots create microsites for germination and assist with dispersal of mycorrhizae (which may be beneficial for germination). However, exposed roots have been observed as a result of digging at sites with dense rabbit populations. Grazing of germinants and seedlings by mice and introduced invertebrates (snails, slugs and millepedes) has been observed in the field and laboratory, and may be having a detrimental impact on population recruitment.

4.3                 Threat matrix

This risk assessment considers the likelihood of a threat occurring (probability), extent and the level of significance of the threat (consequence). These variables are combined in a matrix to provide an ordinal level of risk associated with particular threatening process ranked from 0 (being circumstances where no threat exists) to 3 (where a catastrophic level of threat exists). The derived risk matrix (Table 1) provides a basis for prioritisation of threats to guide Recovery Actions.

Table 1 Threats impacting the Spiny Rice-flower

Note: a) Fire regimes that cause declines in biodiversity include the full range of fire-related ecological processes that directly or indirectly cause persistent declines in the distribution, abundance, genetic diversity or function of a species or ecological community. ‘Fire regime’ refers to the frequency, intensity or severity, season, and types (aerial/subterranean) of successive fire events at a point in the landscape (DAWE 2022). Fire regimes that cause biodiversity decline in temperate grassland communities on the Victoria Volcanic Plain, where Spiny Rice-flower predominantly occurs, have been identified as low fire frequency and fire-competition interaction (DAWE 2022). Low fire frequency (long intervals between fires) cause decline in these populations directly by failing to trigger essential life-history cues to habitat suitability, or through interactions with other threats such as fragmentation (DEWHA 2009; TSSC 2016; DAWE 2022). Traits sensitive to low fire frequency include a combination of short-lived seed banks and low seed-dispersal range (DAWE 2022).

b) Categories for consequences are defined as follows:

Not significant – no long-term effect on individuals or populations

Minor – individuals are adversely affected but no effect at population level

Moderate – population recovery stable or declining

Major – population decline is ongoing

Catastrophic – population trajectory close to extinction

5               Guidance for decision makers

Under the EPBC Act, an action will require approval from the Minister if the action has, will have, or is likely to have a ‘significant impact’ on a matter of national environmental significance, such as a listed threatened species. An action is likely to have a significant impact where it may adversely affect the long-term recovery of the Spiny Rice-flower. The Spiny Rice-flower is sensitive to drastic environmental changes often resulting from development action and is sensitive to certain development activities due to its: isolated, fragmented and restricted distribution, small and declining populations, degraded habitat, and low level of recruitment.

All development proposals and activities within the current (Map 1) and future modelled Spiny Rice-flower distribution that will, or are likely, to result in a decline in the national population should be referred to the Commonwealth government for assessment under the EPPBC Act (see Recovery Actions Table 2). Actions that may require approval under the EPBC Act include but are not limited to actions that result in the loss or reduction of a population or individuals, further clearance, fragmentation or degradation of known or likely and habitat critical to the survival of the species.

The Commonwealth Significant impact guidelines for the critically endangered Spiny Rice-flower (Pimelea spinescens subsp. spinescens) (DEWHA 2009) have been developed to support stakeholders including decision makers, developers, and assessors, to determine whether a proposed action is likely to have a significant impact on the Spiny Rice-flower across its range. These guidelines should be read in conjunction with the Significant impact guidelines 1.1 - Matters of National Environmental Significance (DEWHA 2013).

Significant impact thresholds for the Spiny Rice-flower are found in the Significant impact guidelines for the Spiny Rice-flower, and include the following:

• Any loss of individuals from any population which occurs on the edge of the Spiny Rice-flower’s current known distribution is likely to represent a significant impact.
• Recruitment in Spiny Rice-flower appears to be the overriding limiting factor. Therefore, the following cases are likely to represent a significant impact:

          the loss of more than 5 individuals from a population

          removal of between 40% and 60% of the male plants from a population

• Any fragmentation of a population. Fragmentation may include but is not limited to partial clearing that leads to isolated smaller patches and/or the introduction of a physical barrier to plant dispersal (for example solid fences, transport corridors, walking tracks, easements).
• The limited dispersal ability of Spiny Rice-flower pollinators (<100m) will limit its genetic influence and movement between non-habitat to habitat areas.
• Avoidance measures should be the primary strategies for managing the potential impact of a proposed action, followed by mitigation of residual impacts. To counterbalance the residual impacts that remain after avoidance and mitigation measures, offset proposal consistent with the EPBC Offsets Policy must be prepared before the approval a ‘controlled action’ (DSEWPAC 2012). Any proposed translocation that is a component of a direct offset must be consistent with EPBC Act Translocation Policy (DSEWPAC 2013a) and other policies and existing guidelines (Section 7.6).

Assessment of actions relating to urban development in those parts of Melbourne within the Melbourne Strategic Assessment boundary is considered under that strategic assessment process, i.e., Melbourne Strategic Assessment (MSA) (DSEWPAC 2013b). Strategic assessments are landscape-scale assessments under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) that allow a big-picture approach to protecting biodiversity (DCCEEW 2022). Actions within MSA must comply with MSA requirements but otherwise do not need the assessment or approval by the Commonwealth Government.

6               Implementation of the first Recovery Plan

The first National Recovery Plan for the Spiny Rice-flower (2006) outlined 7 specific objectives for the recovery of Spiny Rice-flower:

• Acquire accurate information for conservation status assessments.
• Identify habitat that is critical, common or potential.
• Ensure that all populations and their habitat are protected and managed appropriately.
• Manage threats to populations.
• Identify key biological functions.
• Determine the growth rates and viability of populations.
• Build community support for conservation.

There has been considerable recovery activities and progresses made during the life of the first Recovery Plan undertaken by the Pimelea spinescens Recovery Team and Pimelea Conservation Trust (PCT), included increased knowledge on species biology, habitat management, population monitoring and identification of additional sites, and improved governance. However, the objectives of the first National Recovery Plan have not been fully accomplished. The implementation of the first Recovery Plan that has been ongoing since 2006 until present are briefly summarised below with further details outlined in Appendix 2.

6.1                 Conservation status assessments

A state-wide survey and database to acquire baseline population data has been initiated but is incomplete. Based on comprehensive population surveys and monitoring that was undertaken at Skipton Common in 2017 to 2020, population size across the distribution was estimated to have declined by as much as 30% in the past 20 years (2000–2020). It is also projected that the whole population is likely to experience similar declines over the next 10–20 years. Listing assessment to update the Spiny Rice-flower conservation status was undertaken by DELWP in 2021 in compliant with the Common Assessment Method (CAM). The assessment concluded that Spiny Rice-flower is eligible for listing under the FFG Act as Critically Endangered in Australia (DELWP 2021).

6.2                 Information on habitat

Comprehensive habitat assessments of all known sites have not been achieved, except for populations located in Skipton Common. Habitat critical to survival in the sense of all habitats within which the populations exist has generally not been fully mapped, and where it has been mapped, the information is often outdated or unreliable as collection method is inconsistent. No bioclimatic indicators have been established but co-occurring species, including threatened species within the habitat, have been identified.

6.3                 Populations and habitats are protected

Site protection and management

Most of the objectives to protect populations on public land and private property targeted in the first Recovery Plan have not been achieved. This was partly due to the incomplete state-wide database; a comprehensive and up to date state-wide database is critical for a species recovery planning.

A Public Authority Management Agreement (PAMA) exists between the Cemetery Trust and DEECA for Spiny Rice-flower populations at Truganina Cemetery. Additionally, a number of Local Government Reserves have been established by councils on their lands. Such strategic acquisition, conservation covenants, and improvements in the reservation status of Crown Land have contributed to the conservation of Spiny Rice-flower and TECs that support the species (TSSC 2016).

The Recovery Team have worked with various stakeholders to ensure that populations and habitats are managed appropriately. Management of threats including herbivore and weed control, livestock and rabbit proof fencing installation and vermin eradication have been conducted in multiple sites (see 6.4 Threats management).

Supplementary and enhancement planting for small and isolated populations have been conducted by local councils and management authorities including Glenelg Hopkins CMA, Brimbank Council, Mooney Valley Council, and Wyndham City Council. Ecological burning to promote regeneration has been conducted at various sites including at Ararat Airfield, Glengower Road, Western Highway Dobie, Chatsworth Road Derrinallum, McKenzie Rd Marong, Jasper Rd Tennyson, Pimelea Nature Conservation Reserve, Altona Nature Reserves and Pioneer Park (Figure 6).

The Recovery Team collaborated with conservation partners such as Lismore Landcare group, Ballarat Environmental Network, Friends of Iramoo, Mt Korong Eco-Watch Association and Corangamite CMA to undertake population monitoring and supplemental planting (Figure 7). Private environmental consultants also actively participated in the implementation of the first Recovery Plan. For example, Aus Eco Solutions conducted recruitment monitoring at Burns Rd Altona site and weed control at Deer Park Boral, Geggies Rd and Ballan Rd, while ABZECO manages six reserves for Brimbank Council. Aus Eco Solutions and Glenelg Hopkins CMA in collaboration with the Recovery Team have conducted seed collection (for enhancement planting) in multiple sites including at Skipton Common, Altona, Sunbury, Deer Park and Mount Mercer (Figure 8).

The Recovery Team through Pimelea Conservation Trust supports the management of two reserves that hold Spiny Rice-flower populations–Altona Nature Conservation Reserve and Pimelea Nature Conservation Reserve. Altona Nature Conservation Reserve is managed by Parks Victoria while Pimelea Nature Conservation Reserve on Kirks Bridge Road is managed by Wyndham City Council.

It was envisaged that a conservation prioritisation would drive the strategic investment and determine the most suitable action(s) to protect and manage a population (Foreman 2012). A preliminary assessment was conducted in 2011/12 to determine conservation priority in which a given population is given a priority score based on population size, area, and tenure-type (Appendix 1). However, not all populations have been assigned with a priority score.

Translocation

While translocation has the potential to result in a conservation outcome, it should still be seen as a last resort, with protecting population and avoidance of disturbance impacts should always remain the highest priority (Pimelea spinescens Recovery Team 2013; Biosis 2014).

The Recovery Team has developed a protocol for Spiny Rice-Flower Translocation (Pimelea spinescens Recovery Team 2013). The protocol includes guidelines for recipient site selection, monitoring requirements, management of a translocated population.

Biosis (2014) conducted the translocation reviews across 11 translocation sites at Altona Nature Conservation Reserve, Burns Road Altona, Ravenhall Grasslands Nature Conservation Reserve (East), Christies Road Ravenhall, Mt Cottrell Nature Conservation Reserve, Gourlay Road Caroline Springs, and Williams Landing A, B, and C. The review has highlighted ways to improve future translocation activities. The review found that translocation survival rate across the sites was 33% on average. Damage to Spiny Rice-flower’s long taproot system during translocation often results in mortality. Notably, the translocation method determines the survival of translocated plants. The review recommendation includes undertaking plant extraction using a tractor-mounted tree spade and transplanting the individual into the prepared recipient site as soon as practicable followed by intensive watering to reduce transplant shock (Figure 9; Biosis 2014).

6.4                 Threats management

Management prescriptions for sites containing Spiny Rice-flower have been developed, however most of them have not been critically assessed on their effectiveness. The Recovery Team identified that the management plan at Lake Borrie site developed by Melbourne Water is an excellent example of an effective plan. Spiny Rice-flower population at Lake Borrie has increased in size by approximately 30% following rabbit and weed control and improved ecological burning. Progresses and changes in the management strategy were also documented in a series of annual reports.

6.5                 Information on key biological traits

An evaluation of reproductive biology, including germination requirements, seed dormancy, seed bank status, fecundity and recruitment have been completed through a PhD project at Victoria University by Debbie Reynolds – who is also the coordinator of the Recovery Team. This PhD project also assessed various supplementary planting methods including direct seeding and strategies for seed sourcing (Reynolds 2013). Building on this knowledge, the Recovery Team has developed guidelines on: Spiny Rice-flower translocation protocol (2013), Spiny Rice-flower monitoring protocol (2015), and Spiny Rice-flower seed collection protocol (2018). Further, an examination of Spiny Rice-flower’s genetic diversity and population structure to better inform conservation actions has been conducted by the Royal Botanic Gardens Victoria (James & Jordan 2014).

Figure 7 Prescribed burning at Pioneer Park conducted with Brimbank Council and contractors in attendance.

Photo © Debbie Reynolds

6.6                 Population growth rate and viability

Although the state-wide database is incomplete and population data are of variable accuracy, monitoring effort on Spiny Rice-flower populations has greatly increased since 2006 and this has improved our knowledge of population structures and trends (also see 6.5 Information on key biological traits). Building on this knowledge, Arthur Rylah Institute developed a population viability analysis (PVA) that is critical to inform management actions related to maintaining population viability and the long-term persistence of Spiny Rice-flower (Figure 3 and Figure 5) (Regan et al. 2021).

Figure 8 Left–The Recovery Team and Mt Korong Eco-Watch Association conducted population monitoring. Right– Supplementary planting and population monitoring at Skipton Common supported by Glenelg Hopkins CMA, Ballarat Environment Network, Pimelea Conservation Trust, Skipton Primary school, Wadawurrung Traditional Owners Aboriginal Corporation, Field Naturalist’s Club Ballarat and the Snake Valley CFA Brigade. Spiny Rice-flower recovery is part of the Glenelg Hopkins CMA’s Victorian Volcanic Plain Recovery Project.

Photo © Debbie Reynolds

Figure 9 Collecting seeds from multiple populations for supplemental planting. Using seeds from different populations help promote genetic diversity within the often isolated and small remnant populations.

Photo © Debbie Reynolds (top) and Aus Eco Solutions (bottom).

6.7                 Community support

The Recovery Team has liaised and built a strong collaboration with Country Fire Authority (CFA), Catchment Management Authorities (CMAs), and key local conservation groups including Skipton CFA, Skipton Landcare, Ballarat Environment Network, Glenelg Hopkins CFA, Corangamite CMA, Glenelg Hopkins CMA, Mt Korong Eco-Watch Association, and Field Naturalists’ Club of Ballarat.

The Recovery Team has undertaken various types of community outreach for Spiny Rice-flower including:

• The production of the Pimelea and Her Grassland Friends children’s book (2015)
• Chapter in Recovering Australian Threatened Species (Garnett et al. 2018) “Spiny Rice-flower: small, unassuming but with many friends” Chapter 6, authors – V Craigie, D Reynolds, N Walsh, S Mueck, L James & P Rudolph
• Digging (up) the Spiny Rice-flower on Soundcloud and on YouTube (2021)
• Doyle et al. (2022) Threatened Plant Conservation for Mitigation: Improving Data Accessibility using Existing Legislative Frameworks. An Australian Case Study. Published in Frontiers in Conservation Science (January 2022)
• Conservation information on State-Wide Integrated Flora and Fauna Teams (SWIFFT) website
• Presentations and talks at community group’s meetings, community education days, and workshops.

Overall, there has been substantial efforts that have been undertaken for the recovery of Spiny Rice-flower. Despite the achieved outcomes to date, there is still an urgent need for recovery actions that put a strong emphasis on protecting key sites as well as managing habitats from threats and gather further knowledge to better inform on-ground management of the species and habitat (Recovery Actions Table 2 and Table 3). It is also evident that continuing the ongoing collaboration with land managers and conservation groups and Traditional Owners, is paramount to progress the species recovery (Recovery Actions Table 4).

Figure 10 Spiny Rice-flower translocation. Top–A tree spade mounted on a tractor is used to extract plant to minimise root damage. Bottom–When the recipient site and salvage site are in a close distant, individual plant is transplanted directly after extraction.

Photo © Debbie Reynolds (top) and © Steve Mueck (bottom).

7               Recovery Plan

The long-term vision for Spiny Rice-flower recovery is to ensure Spiny Rice-flower can survive, flourish, and retain its potential for evolutionary development in the wild through the continuation of threats abatement and maintained or enhanced viable in situ populations.

The first Recovery Plan for Spiny Rice-flower has provided a foundation to further promote the ongoing recovery effort needed to meet the vision through enhancing habitat protection, improving habitat quality and connectivity, and improving Spiny Rice-flower’s population trajectory.

Within the lifespan of this Recovery Plan (10 years), the objectives for Spiny Rice-flower are:

• A maintained or increasing positive trend in the area of occupancy
• A maintained or increasing number of viable populations (compared to 2021/22 baseline counts).
• All populations of the Spiny Rice-flower are identified, managed and protected from key threats to ensure its persistence.
• Community and institutional support are maintained and enhanced.

7.1                 Performance criteria

This Recovery Plan will be deemed successful if by 2032, all the following have been achieved:

1. The number of known viable 2021/22 populations (both wild and translocated) has been maintained or increased from 2021/22 baseline counts.
2. The number of individuals in each population has been maintained or increased from 2021/22 baseline counts.
3. All known populations records are surveyed and accurately and mapped in 2028 and every 5 years thereafter.
4. All known populations are identified, protected and managed to support recovery and persistence.
5. The area of occupancy of Spiny Rice-flower has increased through the establishment and protection of new viable populations.
6. The number of populations subject to formal protection measures has increased by at least 10%.
7. Knowledge of Spiny Rice-flower ecology, recruitment and seedling survivorship, genetic variation, and ecological requirements has increased, and this information has been incorporated into the adaptive management plans.
8. Participation in recovery planning and actions by key stakeholders and Traditional Owners has increased.

7.2                 Actions

The recovery actions will respond to on-ground threats to stop the decline of Spiny Rice-flower.  The recovery actions are designed to meet these objectives within the lifespan of this Recovery Plan and can be categorised under the following strategies.

• Strategy 1: Protecting and managing all populations and habitats (Table 2).
• Strategy 2: Increasing knowledge of reproductive ecology, population and habitat extent, and disturbance ecology, and incorporate this knowledge into adaptive management plans (Table 3).
• Strategy 3: Increasing community awareness and involvement and support of and managers, community, and Traditional Owners to include adaptive habitat management planning in their work which will ultimately support the recovery of Spiny Rice-flower (Table 4).

Strategy 1: Protecting and managing all populations and habitats

This strategy mainly consists of two dimensions – to secure populations or habitat from incompatible use and catastrophic loss (protect); and to appropriately manage threats to all populations and habitat to maintain or improve extent and condition of habitat and genetic integrity (manage) at local, regional and landscape scales

Table 2 Actions to ensure all Spiny Rice-flower populations and habitat are adequately protected and managed (Strategy 1).

Strategy 2: Research on population and management requirements

Closing the knowledge gap strategy involves actions to acquire accurate information for conservation status and assessments of populations’ growth rate and viability; to rigorously define habitat that is critical to the survival; and to identify key biological functions, ecology and management requirements with emphasis on seed and seedling ecology, fire-recruitment dynamics, pollinator and dispersal ecology and impacts of drastic climate change.

Table 3 Actions to address knowledge gap to better inform adaptive management plans for the Spiny Rice-flower (Strategy 2).
 

Strategy 3: Enhanced local community, land managers and Traditional Owners engagement

The actions under this strategy focuses on community or site-based collaboration to ensure the practice of Spiny Rice-flower conservation is adaptive and integrated into local management routines.

Table 4 Actions to support community-based collaboration for the recovery of Spiny Rice-flower (Strategy 3).

7.3                 Implementation and evaluation

This Recovery Plan guides recovery action for the Spiny Rice-flower, its implementation to be coordinated by the national recovery team with identified partners working collaboratively to achieve positive and lasting conservation outcomes for the species. The technical, scientific, habitat management or education components of the Recovery Plan will be referred to specialist groups for research, in situ management, or community education as required.

The Recovery Plan will guide recovery effort for 10 years and will be reviewed within 5 years from the date it’s made under the EPBC Act. Actions and recovery progress will be regularly reviewed by the Recovery Team through a structured review process throughout this period. This will include compiling all information, assessing progress against the performance criteria and objectives to allow adaptive management for the species consistent with national reporting guidelines for recovery teams. The review outcome will determine:

• whether the plan continues unchanged, is varied to remove completed actions, or varied to include new conservation priorities; or
• whether a Recovery Plan is no longer necessary for the species, as either conservation advice will suffice, or the species is removed from the threatened species list.

As part of this review, the listing status of the species will be reviewed to determine whether it needs to be reassessed (down listed) against the EPBC Act species listing criteria.

7.4                 Priorities, timeframes and funding

Spiny Rice-flower requires interventions including control and mitigation of threats, habitat protection, and better understanding of its ecology to support its recovery. Significant progress in recovering Spiny Rice-flower populations is likely to occur if the actions outlined in this Recovery Plan are comprehensively funded and implemented over the next 10 years. The cost of implementing this plan should be incorporated into the core business expenditure of partners, including funding, bodies, to ensure those partners who are responsible for implementing relevant actions can effectively collaborate, prioritise and implement actions to protect the species and ensure its long-term persistence (Garnet et al. 2018). Anticipated funding sources include the Commonwealth, state, and local governments and the Pimelea Conservation Trust fund.

Table 5 outlines the action priorities, timeframes, partners, primary funding sources and costs (where estimable) required to achieve the objectives of the Spiny Rice-flower Recovery Plan. It is expected that Commonwealth and state agencies will use this plan to prioritise investment and actions to protect the species and enhance its recovery, and that projects will be undertaken according to agency priorities and available resources. All actions are considered important steps towards ensuring the long-term survival of Spiny Rice-flower. The recovery process of Spiny Rice-flower is anticipated to be continually evolving and therefore recovery actions of the species may still be required beyond the 5-year review of the Recovery Plan.

Table 5 Priorities, actions, timeframes, estimated costs for Spiny Rice-flower recovery within the 5-year reviewa.

a The action and corresponding priority and cost will be assessed at the 5-year review and adjusted accordingly for the remaining lifespan of this Recovery Plan.

b Values 1-3 are in decreasing order of priority with 3 being lowest priority. The action’s priority was based on the threat risk (Table 1) and implementation of the previous Recovery Plan Appendix Table 2

c Year of the new Recovery Plan. Recovery Plan commencement year = Year 1.

d Indicative amount, based on assumption that this task would be undertaken by a dedicated officer or a number of officers with part of their role dedicated to this specific task (the figure is the approximate costs for the 5 year period based on an estimated percentage of person’s full time equivalent (FTE).

e Indicative amount for one site only.

7.5                 Interactions with existing plans, policies and programs

This Recovery Plan is influenced by, responds to, complements and/or overlaps with a range of other strategic policies and plans. The Recovery Plan seeks to identify common approaches and actions between these existing plans and programs to provide an integrated and efficient approach to the management and recovery of the species. In addition to Commonwealth, State and local government plans and policies, there are protocols that have been developed and/or endorsed by the Recovery Team to guide the recovery actions for Spiny Rice-flower.

Commonwealth government:

• Commonwealth listing advice on Pimelea spinescens subsp. spinescens (Plains Rice-flower, Spiny Rice-flower, Prickly Pimelea) (TSSC 2003)
• Commonwealth listing advice on the Natural Temperate Grasslands of the Victorian Volcanic Plain (TSSC 2008)
• EPBC Act policy statement - translocation of listed threatened species - assessment under chapter 4 of the EPBC Act (DSEWPAC 2013).
• Environment Protection and Biodiversity Conservation Act 1999 Environmental Offsets Policy (DSEWPAC 2012).
• Strategic assessments: policy statement for EPBC Act referrals (DSEWPAC 2013)
• Significant impacts guidelines 1.1 - Matters of National Environmental Significance (DEWHA 2013).
• Significant impact guidelines for the critically endangered Spiny Rice-flower (Pimelea spinescens subsp. spinescens)–EPBC Act policy statement 3.11 (DEWHA 2009b)
• Significant impact guidelines for the critically endangered Spiny Rice-flower (Pimelea spinescens subsp. spinescens)–Background Paper to EPBC Act Policy Statement 3.11 - Nationally Threatened Species and Ecological Communities (DEWHA 2009c)
• Commonwealth Conservation Advice on Natural Grasslands of the Murray Valley Plains (TSSC 2012)
• Conservation Advice Pimelea spinescens subsp. spinescens (Spiny Rice-flower) (TSSC 2016)
• Threat abatement plan for competition and land degradation by rabbits (Department of the Environment and Energy 2016b)

Victoria government:

• Spiny Rice-flower Pimelea spinescens subsp. spinescens: A nationally threatened species of the grassland community (DELWP 2005)
• Flora and Fauna Guarantee Action Statement 132 (revised 2008)–Spiny Rice-flower Pimelea spinescens subsp. spinescens (DSE 2008)
• Melbourne Strategic Assessment Biodiversity Conservation Strategy (2010)
• Melbourne Strategic Assessment–Spiny Rice-flower prescription [Management plan] (DSE 2010)
• Victorian Auditor General’s Office report into Protecting Critically Endangered Grasslands (2020)

Protocols and other guidelines relevant to the recovery actions:

• Spiny Rice-flower translocation protocol (Pimelea spinescens Recovery Team 2013)
• Spiny Rice-flower long-term monitoring protocol (Pimelea spinescens Recovery Team 2014)
• Spiny Rice-flower guidelines for monitoring (Pimelea spinescens Recovery Team 2015a)
• Management in a fire control line for Pimelea spinescens (Pimelea spinescens Recovery Team 2015b)
• Burning Pimelea spinescens (Pimelea spinescens Recovery Team 2017)
• Spiny Rice-flower seed collection protocol (Pimelea spinescens Recovery Team 2018)
• Guidelines for the translocation of threatened plants in Australia–third edition (Commander et al. 2018)
• Plant germplasm conservation in Australia–third edition (Martyn Yenson et al. 2021)

7.6                 Ecological co-benefit

Spiny Rice-flower is a significant flagship species for the conservation of the Critically Endangered Natural Temperate Grassland and other TECs (Figure 10; Table 6). Temperate grasslands and grassy woodlands of the Victorian Volcanic Plain are identified as one of Australia’s most threatened ecosystems where more than 99% and 95%, respectively, have been lost and the remaining pieces are in poor condition (Kirkpatrick et al. 1995; VAGO 2020). Protection of Spiny Rice-flower habitats on public land have contributed to the conservation of multiple TECs supporting the subspecies, i.e., the Endangered Buloke Woodlands of the Riverina and Murray-Darling Depression Bioregions (Cheal et al. 2011), the Critically Endangered Grassy Eucalypt Woodland of the Victorian Volcanic Plain (DEWHA 2009a, b, c); the Endangered Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-eastern Australia (DEWHA 2010); the Critically Endangered White Box-Yellow Box-Blakely's Red Gum Grassy Woodland and Derived Native Grassland (DECCW 2010); the Critically Endangered Natural Temperate Grassland of the Victorian Volcanic Plain (TSSC 2008); and the Critically Endangered Natural Grasslands of the Murray Valley Plains (SEWPAC 2012; TSSC 2012).

The Victorian Volcanic Plain bioregion is also one of 15 biodiversity hotspots in Australia and home to more than 65 threatened species listed nationally and 173 threatened species listed in Victoria (DSEWPAC 2011; VAGO 2020). Threatened plant species co-occurring with Spiny Rice-flower in the Natural Temperate Grasslands of the Victorian Volcanic Plain include: Dianella amoena (Matted flax-lily, Endangered), Diuris basaltica (Small Golden Moths, Endangered), D. fragrantissima (Sunshine Diuris, Endangered), Lepidium hyssopifilium (Basalt Pepper-cress, Endangered), Leucochrysum albicans var. tricolor (Hoary Sunray, Endangered), Prasophyllum diversifolium (Gorae Leek-orchid, Endangered), P. frenchii (Maroon Leek-orchid, Endangered), P. suaveolens (Fragrant Leek-orchid, Endangered), Pterostylis basaltica (Basalt Greenhood, Endangered), Rutidosis leptorrhynchoides (Button Wrinklewort, Endangered), Dodonaea procumbens (Trailing Hop-bush, Vulnerable), Glycine latrobeana (Clover Glycine, Vulnerable), Lepidium aschersonii (Spiny Pepper-cress), Senecio macrocarpus (Large-fruit Groundsel, Vulnerable), Xerochrysum palustre (Swamp Everlasting, Vulnerable) (DSEWPAC 2011). Spiny Rice-flower grasslands habitat also support a wide range of threatened fauna including the Synemon plana (Golden sun moth, Vulnerable), Delma impar (Striped Legless Lizard, Vulnerable) and Litoria raniformis (Growling Grass-frog, Vulnerable). Incorporating threats mitigation and habitat management for Spiny Rice-flower into the current recovery actions will provide broader and continuous biodiversity benefit and will culminate in the formulation of best practice for the management of grassland ecosystems and the associated species.

Figure 11 Spiny Rice-flower plant growing in its grasslands habitat.

Photo © Debbie Reynolds

Table 6 Threatened Ecological Communities (TECs) known and likely supporting the Spiny Rice-flower

7.7                 Social and economic impacts

Land on which the grasslands and grassy woodland occur, where Spiny Rice-flower habitats are predominantly situated, is fertile and productive. It now supports a diversity of agricultural industries, which are essential to the economic and social viability of towns and communities across Victoria. Many populations are found within Melbourne growth boundary. The expansion of the urban will also bring substantial economic and social benefits to Melbourne but will potentially impact Spiny Rice-flower. Where conflict occurs between actions outlined in this Recovery Plan and the interests of others, consultation between parties must occur. Any development actions must consider that Spiny Rice-flower is listed as Critically Endangered under the EPBC Act, and actions that have or likely have significant impacts on the entity must be referred for an assessment under the EPBC Act (see also Guidance for decision makers).  

Social Impacts

Numerous social benefits will flow from building and maintaining relationships with a diverse array of stakeholders through the implementation of this Recovery Plan:

• Fulfilment of broad community expectations for the maintenance of biodiversity, and the long-term protection of grasslands and grassy woodlands for the enjoyment of present and future Australians.
• Informing and supporting community groups like Traditional Owners and Custodians, environmental-based and agricultural-based networks with a passion for protecting and restoring natural landscapes, while fostering a sense of pride in their contribution to conservation programs.
• Acknowledgement and respect of the various Indigenous communities and their history, with on-going connections to traditional lands and cultural practices including natural resource management.
• Identification of landholder motivations and the range of extension measures required to effectively educate landholders in wider conservation issues (i.e., a consistent message across various sources); that inspires positive changes in landholder perceptions and actions regarding biodiversity conservation.
• Demonstrating sustainable farm practices and the value of ecosystem services, while enhancing the long-term productivity of agricultural systems to hand to following generations of farmers.
• Addressing landholder/farmer concerns about the control of weeds and other pests.
• Negotiating with private landholders to adopt voluntary conservation measures for sites with populations of threatened species and ecological communities.
• Negotiating with public land managers such as the Victorian Catchment Management Authorities (CMA), local government areas, and various water, road, rail, and cemetery authorities to adopt best practice management guidelines, or supported by legal instruments such as PAMAs, for the protection of key sites and populations.
• Promoting the work of community-based organisations, such as the Country Fire Authority (CFA) who by conducting fuel reduction burns are helping to protect local communities from fire, as well as providing ecological benefits for grasslands.
• Any protection measures required at sites (e.g., fencing, signage, track closures) will generally have minimal impact on current recreational activities; the way some reserves are managed in relation to public recreational activities may also be affected.
• Improving the intrinsic natural values and visual amenity enjoyed by visitors to such areas and increasing opportunities for tourism and education.

The negative social impacts are mostly associated with the restriction of rural and residential, agricultural and infrastructure development on land containing threatened populations or ecological communities:

• Where any alteration or rejection of development proposals will prevent or reduce the delivery of essential services that are required by the community, although the extent of this impact will vary from site-to-site and will depend upon the type of proposed development and the availability of alternatives.
• Where there is a need to conserve remnant grasslands on cemeteries, this may limit the availability of burial plots.

Economic Impacts

The recovery actions stated in this Recovery Plan primarily related to the establishment of a network of reserves or managed lands for the long-term conservation have various economic implications. Any land acquisitions or rejection or alteration of proposed developments will have economic impact on government authorities, land holders, developers and parties serviced by the land and/or development. Some economic and conservation trade-offs potentially emerge from the actions includes the following:

• Habitat conservation may increase restrictions on particular land-uses such as reduced grazing opportunities or prevent some agricultural enterprises from converting to cropping or introduced pastures.
• Adequate protection and conservation of habitat critical for the survival of the Spiny Rice-flower, that is also prime land for development, will be expensive to acquire for the parks and reserve system. The need to establish buffer zones around habitat critical for the survival of the species may also cause a trade-off in economic returns.
• Population protection and threat mitigation can be expensive due to the extent of threats (e.g., weed diversity and coverage), and the on-going need for management.
• Reserve management costs are likely to be much higher per unit area due to the patchy quality and degraded condition of many remaining sites. Remnants are often isolated and present logistical issues, such as the distance and time to travel to sites.
• Surveying for the presence of threatened species can be costly and time consuming, and access to private lands for this purpose is sometimes problematic. Therefore, it may not be practical to survey all potential sites and habitats within the time frame of this Recovery Plan. Conservation agencies should use all other means at their disposal for obtaining this information, including the survey work undertaken by consultants and students, and then incorporate this information into relevant databases.
• Some of the costs of retaining native grasslands on farms include lower economic returns, a decrease in pasture production over winter, under-employed resources, and research and marketing needs to establish and run new enterprises.
• There are also considerable investment costs involved in establishing a grasslands restoration industry, including the need to purchase or retire farmland, develop specialist equipment for soil bed preparation, sowing and harvesting, along with procuring sufficient seed and the skilled labour required. But this initial significant investment would reduce the long-term costs of restoration, which are required if large tracts of grasslands and grassy woodlands are to be created.

However, there are considerable economic benefits to also take into account:

• Many populations of threatened species or remnants of the ecological communities are at sites (e.g. parks and reserves) where management for biodiversity conservation is already a high priority.
• An asset-based approach is normally taken by natural resource management agencies, where a cost-benefit analysis can reveal the greatest biodiversity outcomes for the least investment. Management efforts that take a whole-of-ecosystem perspective naturally tend to benefit numerous co-existing species.
• Protection measures such as providing information to managers, installation and maintenance of fencing and signposts can generally be achieved at minimal cost.
• Financial and other incentives are available through various schemes run by regional natural resource management authorities to assist conservation measures. These funds provide assistance and help offset costs associated with protection (e.g. fencing and signage), and/or reduced grazing opportunities. Some councils also have rate rebate schemes for landholders who undertake weed control.
• Visitors to these natural areas provide economic benefits for the local districts, and the landscape amenity can also help increase property re-sale values.
• Other economic benefits of maintaining native grasslands on farms include: their low use of inputs such as fertilisers, enhanced response to summer rain, improved animal health, reduced need for supplementary feeding, production of finer wool, reduced drought risk, reduced fire risk, enhanced land and water protection, improved human health through reduced use of chemicals and reduced stress, opportunities for new farming enterprises such as seed collection and native plant harvesting, and enhanced opportunities for recreation, tourism, and biodiversity conservation.
• Finally, any investment in the protection and enhancement of grasslands and the grassy woodlands will be more than compensated by the value of the ecosystem services provided, including: habitat for beneficial native species, maintenance of soil structure, fertility and prevention of erosion, maintenance of water quality, prevention of soil and water salinity, provision of a carbon sink, shade and shelter for crops and livestock, drought resistant low-input grazing resources, provision of resources for the apiary industry, a source of seeds for regeneration, and maintenance of wild gene pool.

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Appendix 1

Table A1 Population information for the Spiny Rice-flower (November 2021)