Victorian Banksias Conservation

• 
  1. Purpose of team-page
• 2. Victorian Banksias workshop - 15th May 2020
• 3. Description and habitats
• 4. Research and management projects
• 5. References
  6. Information sharing

 

 

 

 

These are some of the Banksia research and management projects that are happening in Victoria. To add your projects, contact SWIFFT and provide the following details:

• Project name
• Contact name/s & organisation
• Email address, weblink
• Project type (research, management)
• Location/s
• Timing (years)
• 200 – 300 word summary (include threats, aims, activities, outcomes)

Banksia canei

Mountain Banksia seed production and fire intervals in Gippsland

• Lucas Bluff, Nevil Amos, Annette Muir (DELWP)
• lucas.bluff@delwp.vic.gov.au
• Project type: research, management
• Location: East Gippsland
• Timing: 2017 – 2018

Summary

A single-year project monitored seed production on Banksia canei in relation to fire intervals. The species has life history characteristics that make it vulnerable to decline with short fire intervals – it is killed by fire and has no soil seed bank. There is uncertainty about whether current planned burning regimes are compatible with its time to reproductive maturity time and hence population persistence.

Data were collected on cone production (seeds) in 2017-2018 for 170 individual B. canei plants in Gippsland Region. A lack of variability in fire history in the study area resulted in one time-since-fire class for the seed analysis. Plants originating from fire in 2003 (14 years old) had a median value of 11 closed cones per plant. Further monitoring of seed production is needed to determine reproductive thresholds.

About a third of recorded B. canei sites were burnt in the widespread bushfires at the start of 2020. Ground checking is needed to verify the extent of adult plant death and levels of seedling recruitment in the burnt areas, and comparison with unburnt sites.

Mountain Banksia bushfire recovery in north-east Victoria

• Glen Johnson (DELWP)
• glen.johnson@delwp.vic.gov.au
• Project type: management
• Location: North-eastern Victoria
• Timing: 2017, 2020

Summary

A small isolated population occurs in Burrowa Pine Mountain National Park. Prior to the 2020 bushfires, this population was affected by drought, and inspections of some areas in 2017 revealed almost all Banksia canei plants were lacking mature seed-bearing cones. Given the limited seed source prior to the 2020 bushfires, which were rated as being high severity in Burrowa Pine Mountain NP, there are concerns for its recovery. A number of bushfire recovery works are planned in 2020 by Regional DELWP and Parks Victoria staff. Sites will be inspected to determine: fire severity per stand; presence of re-sprouting or germination or seed collection potential; and level of exotic or native herbivore browsing.

Banksia integrifolia

Water stress, shrub encroachment and declining Coast Banksia

• Contacts: Stefan Gouws, John Morgan (La Trobe University)
• S.Gouws@latrobe.edu.au
• Project type: research
• Locations: Wilsons Promontory
• Timing: 2018 – 2019

Summary

Banksia integrifolia (coast banksia) decline at Wilson’s Promontory National Park has been well documented since the 1970’s, yet no single cause has been found. B. integrifolia is a foundational species in the grassy woodlands at Wilson’s Promontory, providing hollows for nesting sites and floral resources for native wildlife. The coastal grassy woodlands have been subjected to large scale shrub encroachment by Leptospermum laevigatum (coast tea-tree).

This study investigated the decline of B. integrifolia trees due to shrub encroachment. We hypothesised that B. integrifolia can access groundwater resources, that the presence of a shrub layer limits water availability for B. integrifolia individuals and that water stress in B. integrifolia increases when surrounded by a dense L. laevigatum understorey. In a glasshouse experiment we found that B. integrifolia have a dimorphic rooting system that enables them to access groundwater resources. Our natural experiments found that encroachment limits water availability for B. integrifolia, especially at depth, and that B. integrifolia individuals surrounded by shrubs had a higher degree of water stress compared to unencroached banksias.

These results indicate that water stress of shrub encroached B. integrifolia could lead to lower productivity, and that shrub encroachment and long-term low intensity drought is contributing to the decline of B. integrifolia across Wilson’s Promontory National Park.  

Banksia marginata

Cockatoos and recruitment limitation of Silver Banksia

• Simon Heyes, John Morgan, Susan Hoebee (La Trobe University)
• S.Heyes@latrobe.edu.au
• Project type: research
• Location: Western Victoria
• Timing: 2016 – 2019

Summary

There is much evidence, both historic and contemporary, that Silver Banksia (Banksia marginata) across the Victorian Volcanic Plains were common and widespread. However, historic land clearing has left many stands in a highly fragmented state. Some of these stands of B. marginata suffer from recruitment and fruit set failure.

In our recent publication in Plant Ecology, we tested the hypothesis that populations of B. marginata are experiencing widespread recruitment bottlenecks, by examining tree size-class distribution and production of infructescences (cones) of 15 populations.  We found no evidence of widespread recruitment bottlenecks or a failure to set seeds; most populations were recruiting, though we did find evidence of declining recruitment with population size, suggesting evidence of an Allee effect. The proportion of trees without cones varied between populations; three populations had large numbers of trees (40%) lacking mature fertile cones. Another hypothesis is that this may, in part, be due to excessive seed predation by Yellow-tailed Black Cockatoos (Calyptorhynchus funereus). Recent work has investigated removal of B. marginata cones by cockatoos and what this may mean for B. marginata conservation.

Managers should focus on minimising threats to seedling survival and augment populations below 100 individuals to improve recruitment and maintain stand persistence in the landscape.

Genetics, climatic niche and Silver Banksia

• Adam Miller (Deakin University)
• a.miller@deakin.edu.au
• Project type: research, adaptive management
• Location: South-eastern Australia
• Timing: 2015 – 2019

Summary

Habitat fragmentation imperils the persistence of many functionally important species, with climate change a new threat to local persistence due to climate niche mismatching. Predicting the evolutionary trajectory of species essential to ecosystem function under future climates is challenging but necessary for prioritizing conservation investments.

In a new publication that appeared in the journal Evolutionary Applications, our team used a combination of population genetics and niche suitability models to assess the trajectory of Banksia marginata from south-eastern Australia. We demonstrate significant genetic structuring among, and high level of relatedness within, fragmented remnant populations, highlighting imminent risks of inbreeding. Population simulations, controlling for effective population size, suggest that many remnant populations will suffer rapid declines in genetic diversity due to drift in the absence of intervention. Simulations were used to demonstrate how inbreeding and drift processes might be suppressed by assisted migration and population mixing approaches that enhance the size and connectivity of remnant populations. These analyses were complemented by niche suitability models that predicted substantial reductions of suitable habitat by 2080; ~30% of the current distribution of the species climate niche overlaps with the projected distribution of the species climate niche in the geographic region by the 2080s.

Our study highlights the importance of conserving remnant populations and establishing new populations in areas likely to support B. marginata in the future, and adopting seed sourcing strategies that can help populations overcome the risks of inbreeding and maladaptation. We also argue that ecological replacement of B. marginata using climatically suited plant species might be needed in the future to maintain ecosystem processes where B. marginata cannot persist. We recommend the need for progressive revegetation policies and practices to prevent further deterioration of species such as B. marginata and the ecosystems they support.

Seed orchards for restoration and genetic diversity

• Contact: Bill Weatherly (Friends of Forgotten Woodlands)
• www.friendsoftheforgottenwoodlands.org.au 
• Project type: adaptive management
• Location: Western Victoria
• Timing: 2014 – 2020

Aims

Locating and propagating from all Victorian Volcanic Plains (VVP) remnants to build a network of seed orchards and seed production areas (SPAs) and other plantings. Rebuilding genetic diversity and providing reliable seed sources. Establishing SPAs with climate match genetics incorporated. Hopefully rebuilding a little of a keystone ecological component.

Activities

Friends of the Forgotten Woodlands (FoFW) is a volunteer group, and includes leading researchers in ecology and genetics, and their advice and contribution informs all our activities. FoFW also enables discussion and facilitation of research work within the group. The immediate focus was location of all remnants and propagation, as considerable decline and loss was occurring, and in parallel building and adding to our knowledge base. FoFW has been supported with several grants, including a 3-year Biodiversity and Community Action Grant, which have greatly increased our effectiveness and scope.

Outcomes

Adam Miller (Deakin University) undertook investigation of levels of genetic diversity of the fragmented remnant populations, and also advised on design of SPAs incorporating climate adaptation. Since then we have encouraged and supported research investigating population structure and status (Simon Heyes, La Trobe University), genetic movement within populations (Adam Miller), and pollination (Graham Jury, La Trobe University).

Since 2014 we have planted orchards of VVP Banksia marginata, and Sheoak and Bursaria. This has been on public and private land at 16 locations – a total of 5880 plants growing, GPS recorded with provenance. We have also distributed 7000 trees to 28 landholders, several locations with GPS records. 

Our group has a wide range and depth of experience, and we work to best practice with best advice. As well as the knowledge and experience that members of FoFW brought to the group, we have added to this collective experience through what we have learned in building the project and implementing it. We have successfully set up large SPAs and learned to manage the logistics. We will always be happy to share information with others working to build their projects.

Seed orchards and climate change

• Contact: Cathy Olive (Euroa Arboretum)
• cathy.olive@euroaarboretum.com.au
• Project type: adaptive management
• Location: North-eastern Victoria
• Timing: 2004 – 2019

Summary

The goal of the project has been to establish large, self-sustaining populations of Banksia marginata, with a broader genetic base, that could be used as seed orchards in the future.

Euroa Arboretum Seed Production Area

The SPA was set up in 2004. Around 350 plants were planted over a number of years, from 9 provenance sources in the Strathbogies and Tooborac areas. In 2015, 80 trees remained, with 6 provenances represented. 

The work of Dr Linda Broadhurst (CSIRO) has shown that the Euroa Arboretum Banksias are genetically more robust than the wild populations, but still show inbreeding depression. Since 2015, plants from Chiltern, Ararat, and Pastoria have been added to enhance genetic robustness.  We are also adding drier climate adapted plants.

A large irrigation system was installed in 2017 to irrigate the site from early summer until April. There have been large losses of Banksia after extreme heat waves over 40 degrees, with at least 40 mature trees dying per year for the past 2 years. This has also happened at the Benalla Seed Production site.

Goulburn Broken CMA Silver Banksia project

This project was started in 2012, with funding from the Victorian Biodiversity Fund for 6 years. The purpose is to build a landscape of Silver Banksia woodlands.

Initially there was a shortage of seed to meet demand. Banksia plants were grown and given to landholders to establish seed production sites. Sites are ideally large scale, with several hundred plants per site. Landholders need to commit to summer watering in the first year. There is an average success rate of 50 –60%.

Over 8 years, 18,000 Silver Banksias have been planted across the GBCMA areas, but survival rates are yet to be measured.

Banksia ornata

Demographic shift in fire-killed serotinous Desert Banksia

• Neal Enright, Joe Fontaine (Murdoch University)
• N.Enright@murdoch.edu.au
• Project type: research
• Location: Grampians & Little Desert National Parks
• Timing: 1990’s, 2017

Summary

The aims of this work were to investigate:

• Banksia ornata population viability in relation to fire regime, and critical minimum fire interval (and optimum) for population persistence.
• Evidence for climate change impact on seed production and accumulation by plant age, by comparing 2017 data with 1990’s data.

Field data collection was undertaken across the available range of ‘time since fire’ (tsf) sites in the Grampians and Little Desert. Plant size (height, canopy width) and total cone crop per plant were measured for a minimum of 60 plants per fire age area. Follicle counts were made on burned cones to assess if there were changes in follicles per cone over time.

Monthly rainfall, temperature and SPEI (Standardised Precipitation – Evaporation Index) data was obtained for the nearest climate stations. Cumulative rainfall deviation from mean/median was compared for populations of similar tsf age in 2017 vs 1990’s.

There was a marked decrease in total cones per B. ornata plant at both Grampians and Little Desert tsf chronosequence sites in 2017-18 as compared to 1990’s. Declines in cone store per plant correlate with decreased rainfall and increased SPEI.

Populations will be more vulnerable to decline and loss under short interval fire, and in fact will need longer inter-fire intervals to accumulate seed stores sufficient to best guarantee future persistence. Even with longer time to accumulate a sufficient seed bank, the increasingly dry climate will reduce the number of years when post-fire conditions for recruitment are favourable.

Dieback of Desert Banksia in Little and Big Deserts

• Rachel McIntosh (La Trobe University)
• R3MCINTOSH@students.latrobe.edu.au
• Project type: research
• Location: Little and Big Deserts
• Timing: 2019 – 2020

Summary

As part of a plant community fire study in Little and Big Deserts in western Victoria, we are collecting demographic data (height, life-stage, presence of flowers and fruits) for key fire response species including Banksia ornata. Data has not been analysed as yet. During our field season in 2019 we observed a high number of senescing and dead Banksia ornata. Senescence appeared to begin at a single stem and then radiated as it progressed. We visited 96 sites in the Little and Big Deserts and observed dead or senescing Banksia ornata at almost every site. Further investigation is needed into the extent and causes of this dieback.

Banksia serrata

Drought and dieback in Saw Banksia in Gippsland

• John Morgan, Aleyna Firat (La Trobe University)
• J.Morgan@latrobe.edu au
• Project type: research
• Location: East Gippsland
• Timing: 2019

Summary

As temperatures and drought become more extreme, ecological thresholds for survival may be increasingly exceeded. In this study, we observed extensive dieback of Saw Banksia (Banksia serrata) in central and east Gippsland. This likely occurred in 2017/8 following a period of record high temperatures and very low rainfall.  At one large stand, we found substantial mortality (biased towards larger sized plants) and extensive dieback (across all sizes of plants). We hypothesise that water-stress thresholds were exceeded, contributing to a landscape-scale response. If extreme climate trends continue, further declines of B. serrata populations might be envisaged

Banksia spinulosa var cunninghamii

Hairpin Banksia demography and fire management

• Contacts: Annette Muir, Lucas Bluff (DELWP)
• annette.muir@delwp.vic.gov.au
• https://www.ari.vic.gov.au/research/fire/fire-regimes-for-banksias
• Project type: research, adaptive management
• Location/s: East of Melbourne, East Gippsland
• Timing: 2014 – 2020

Summary

Research by Arthur Rylah Institute (ARI, DELWP) on the life cycle of Banksia spinulosa var cunninghamii (Hairpin Banksia) is being used by fire managers in DELWP and Parks Victoria to help maintain plant diversity in forests when applying fuel reduction burns.

Hairpin Banksia typifies plants that decline if burnt too often: because they don’t resprout after fire; take a long time before producing seed; and have no soil seed banks. It’s important to determine the minimum time between fires needed for these plant types to produce sufficient seed for recruitment.

Seed production and seedling recruitment in response to fire were studied at two Hairpin Banksia populations; just east of Melbourne, and in far east Gippsland. Results indicate that fire intervals of at least 15 years enable Hairpin Banksia populations to maintain an adequate seed source for renewal. Very low numbers of seedlings were recorded at almost all sites, and it’s unclear as to the relative influences of fire severity, climate change or other factors on germination and survival.

Guidelines to maintain Hairpin Banksia populations have been produced by ARI in collaboration with operational burn planners in DELWP and Parks Victoria. These include: checking cone production prior to burning; varying burn intensity; patchiness within burns; and delaying burns in drought conditions.

However, the huge bushfires across East Gippsland at the start of 2020 have impacted almost all of the Hairpin Banksia populations there. DELWP spatial data indicates that about 30% of the species range in East Gippsland was also burnt in the ten years prior to the bushfires. Seed production in Hairpin Banksia under ten years of age is likely to be insufficient for replacement recruitment. Ground verification in Spring 2020 is needed to confirm the effects of different fire severity, and levels of seedling recruitment.

Hairpin Banksia seed set and pollination constraints

• Madison Hughes, Susan Hoebee (La Trobe Uni)
• M.Hughes@latrobe.edu.au, S.Hoebee@latrobe.edu.au
• Project type: research
• Location: Dandenong Ranges
• Timing: 2018 – 2019

Summary

In the greater Melbourne region of Victoria, reproductive success in several small populations of Banksia spinulosa var. cunninghamii is minimal, even though plants are of reproductive age and successfully develop inflorescences. Possible reproductive constraints limiting seed set within one of these small populations (Dandenong Ranges) were assessed during the 2018 flowering period and contrasted against a larger, more fertile population (Gembrook area). Pollen viability, florivory and floral visitation were compared between the two sites.

Pollen viability was high in both sites, although flowers opened later at the Dandenongs site. Florivorous larvae within Banksia inflorescences were found at both sites and may impact reproductive success. The two sites had different proportions of mammals and birds visiting inflorescences; with a greater number of species recorded from the Gembrook site. It remains unclear if differences in pollinating guilds between the two sites is impacting reproductive success.

Future studies would benefit from assessing pollen loads and pollinator effectiveness, whilst also extending the study to observe more populations of B. spinulosa var. cunninghamii. Overall, these results suggest that a variety of factors could be impacting reproductive success in small, reproductively poor populations of B. spinulosa var. cunninghamii.

Banksia croajingolensis

Facilitating the conservation of Banksia croajingolensis

• Susan Hoebee (La Trobe University); Abigail Wills (Envite Environment); Max Elliott (Friends of Mallacoota)
• s.hoebee@latrobe.edu.au; abigailw@envite.org.au; friendsofmallacoota@gmail.com
• Project type: monitoring, research, citizen science, management
• Location: East Gippsland, Corajingolong National Park
• Timing: November 2021 – 2022

Summary

This project brings together researchers from La Trobe University, ecological restoration practitioners from Envite Environment, and local community members through the Friends of Mallacoota in an initiative to secure the future of East Gippsland’s Banksia croajingolensis.  This endangered species is known only from a single drainage line South of Shipwreck Creek in the Croajingolong National Park, a site that was severely burnt in the 2019/2020 megafires. Very little is known about the biology of B. croajingolensis. There is even a question about its origin, with Flora of Victoria suggesting that it may be a hybrid between other species with which it co-occurs. We are undertaking surveys to assess the post-bushfire response of B. croajingolensis and combining this with genomic assessment of diversity and structure of the resprouting or emerging plants.  The genomic uniqueness of the species will also be assessed relative to putative parental taxa (B. marginata and B. integrifolia), along with another taxon that is thought to be closely related (B. paludosa).  The genomic outcomes will lead to practical management recommendations including, for example, ex situ collections. In this space, propagation of seed and cuttings by the Friends of Mallacoota is underway to serve as an insurance population in case of future environmental catastrophes.

Seaford Banksia Arboretum

• Mornington group of Australian Plant Society, Victoria
• Ross Shepherd co-ordinator Seaford Banksia Arboretum.   
• Planting of Banksia species
• Corner of Seaford Road and Wells Road in Seaford, Victoria 3198
• Commenced February 2022 (ongoing planting and maintenance) Updates on Banksia Lovers facebook

Summary

This community project is aimed at planting out approx. 2 Ha of VicRoads roadside land exclusively with Banksia species. At present the project is expecting to plant some 2000 or so Banksias.

Plants are to be about 2-3M high and in this instance be as floriferous as possible. Species include; B. prionotes, B. praemorsa (three shades), B. serrata of which a local form stay around 3.5M in this location, B. Robur for the swampy areas along with B. occidentalis, B. ‘Giant Candles’, B. ericifolia, B. spinulosa forms, possibly B. marginata and many others.