Conserving alpine habitats and species challenges, collections and collaboration

Megan J. Hirst, Victorian Conservation Seedbank, Royal Botanic Gardens Victoria

A major challenging and confronting issue in the Australian alpine system is the relatively recent (that is, since European settlement) proliferation of agents of negative change to these areas of high conservation value and biological importance. The consequent impacts of these changes require serious attention to allow the maintenance of ecological connectivity and biodiversity and to halt the continuing demise of biodiversity across these systems.

Meg Hirst

This article explores some of the challenges, the collections underway and collaborations, including those of the Victorian Conservation Seedbank, aimed at conserving alpine ecosystems.

Challenges

Some of the major challenges to the alpine environment include the long-lasting effects of hooved feral animals (Driscoll et al. 2019), infrastructure development (Good 1995), tourism (Pickering et al. 2003), the introduction of numerous exotic species (Johnson & Pickering 2009), increasing fire severity and frequency (Camac et al. 2003) and the effects of increased warming from climate change on plant physiology and community composition (Pickering 2007). These are not equally contributing factors across the entire alpine region, and not all alpine ecological communities are affected equally.

Within the alpine zone there are known threatened ecological communities with limited geographic distribution such as alpine sphagnum bogs and associated fens that are currently listed as endangered under the Environmental Protection and Biodiversity Conservation (EPBC) Act 1999. These specialised habitats are of national interest due to their role in regulating and filtering water flows to major river systems. They are considered an integral part of Australian mainland water catchments, valued at approximately $9 billion to the annual Australian economy (Worboys et al. 2011). These bogs and fens form unique communities that contain many endemic plants and provide habitat to a range of similarly localised native wildlife (for example, the Alpine Water Skink in Victoria, and the Corroboree Frog in New South Wales).

In the Victorian alps, the EPBC-listed vulnerable Lobelia gelida (Fig. 1) and Brachyscome tadgelii occur only in shallow ephemeral pools and depressions associated with the listed sphagnum bog community. Damage to these bogs and fens by feral hooved animals – horses, cattle and deer (Fig. 2) – affects local hydrology and the subsequent ability of the bogs to regulate and filter water. This exposes these vulnerable endemics to continued geographic and environmental range reduction.

Ex situ seed conservation is one of a suite of strategies to support species survival in the wild, and in this case in vulnerable alpine communities. It is considered a complementary approach to ensure biological diversity is conserved while supporting in situ activities such as restoration, reintroduction and/or translocation. Research into germination and seed dormancy strategies using ex situ alpine seed collections provides a greater understanding of how alpine plants grow and establish, especially those confined to small pockets of specialised habitat, and how these species could respond to changes within their isolated niches (Fig. 3).

Figure 1. From left to right: Neville Walsh (RBGV), Andre Messina (RBGV) and Michelle Doherty (Parks Victoria) inspecting plants of the vulnerable Snow Pratia Lobelia gelida, growing in shallow ephemeral pools on Mt Buffalo. Photo: Darryl Whitaker, March 2020.

Figure 2. Feral horses on the Bogong High Plains near Mt Jim within proximity of alpine bogs and associated fens and the vulnerable alpine endemic Brachyscome tadgellii, March 2021. Photo: M. Hirst.

Figure 3. From left to right. Ex situ collection of Lobelia gelida seed under magnification. Photo: B. Hare. The mat forming Lobelia gelida growing at Mt Buffalo. Photo: N. Walsh. Lobelia gelida growing in a container under nursery conditions. Photo: M. Hirst.

Collections

Ex situ seed banking

Globally, botanic gardens make a significant contribution to plant conservation, with a strong emphasis on the preservation of ex situ plant collections of wild origin via whole plants, seed, or tissue culture (O’Donnell & Sharrock 2017). The Australian Seed Bank Partnership (ASBP)3 is an active alliance of 12 institutions across all states and territories, including botanic gardens, that aims to conserve native plant diversity through significant ex situ seed collections at a national scale while building, researching and sharing knowledge of ex situ seed banking. The Victorian Conservation Seedbank (VCS) is a member of the ASBP and is located within the National Herbarium at the Royal Botanic Gardens Victoria (RBGV). The VCS has been in operation since 2005, making long-term ex situ seed collections of Victorian endemics as well as species at risk. There has been a strong emphasis on alpine seed collections by the VCS, with particular reference to species with very limited geographic distributions.

Collaborations

Understanding how species may respond to changes in their environment is an important research area allied to ex situ seed conservation. However, collecting sufficient seed of rare and or threatened species to ensure a quality ex situ collection for long-term storage is not always possible, with further challenges arising when wanting to design research questions around species with limited seed numbers. A collaborative approach in ex situ seed conservation research can provide greater opportunities and support to target specific plant groups as well as ecological communities affected by recent catastrophic events, such as the 2019–20 bushfires in south-eastern Australia. Collaboration across government organisations and within the ASBP has enabled critical work to be funded in fire-affected areas including the in situ assessment of individual species, the collection of critical plant material for ex situ conservation, and germination and viability studies.

Research collaborations with the Victorian Conservation Seedbank

The VCS has recruited new RBGV staff members Dr Rebecca Miller (seed scientist), Simon Heyes and Daniel White (research assistants), making our seed team the biggest it has ever been (currently six members)! We are now in possession of some amazing diagnostic equipment to assist with our work, an x-ray machine (see composite image in Fig. 4), thermogradient plate, a scanning electron microscope and growth cabinets, enabling us to expand seed research as well as to conduct germination and viability studies.

A collaborative project is currently under way involving the VCS, Dr Adam Cross of Curtin University and Professor Ary Hoffmann of the University of Melbourne. They are examining the thermal optima of rare and threatened species with an emphasis on alpine endemics. Temperature is a critical abiotic factor affecting germination. Understanding how species may respond to increasing temperatures can provide insight into the optimal temperature range for germination to occur and help illuminate the complex issues around seed dormancy. This study is especially interested in how populations of the same species may respond to temperature differences and what this may tell us about their ecology. It is also attempting to unravel questions relating to ecological communities such as the threatened bogs and fens on the Bogong High Plains and the seed ecology of species such as Brachyscome tadgellii (Fig. 5).

Figure 4. A composite x-ray image of various ex situ seed collections made possible by the acquisition of an x-ray machine at RBGV, a key diagnostic piece of equipment. Image: A. Robinson, 2020.

The Raising Rarity project is a collaborative effort involving the VCS, colleagues from the RBGV Cranbourne and two honorary academics at the University of Melbourne (Dr Susan Murphy and John Delpratt). It seeks to raise awareness of the plight of our flora in ecosystems that are severely threatened by habitat loss, fragmentation and climate change by growing and displaying rare and threatened Victorian species in an accessible horticultural setting. Plants are grown by seed in containers and transplanted to the Research Garden located within the Australian Garden at RBGV Cranbourne. We are working with rare plants that we believe have the potential for use in horticulture and so far have tested 16 species. We record germination rate, growth and time to flowering as well as their overall performance. Species tested include Lobelia gelida (Fig. 4) and Brachyscome tadgellii (Fig. 5) as well as other interesting alpine species, Argyrotegium nitidulum, Podolepis laciniata and Wahlenbergia densifolia.

Figure 5. From left to right. Ex situ collection of Brachyscome tadgellii seed under magnification. Image: B. Hare. Brachyscome tadgellii growing in different container sizes under nursery conditions. Photo: M. Hirst.

Continuing our focus on the Australian alps, the RBGV will be involved in an exciting Australian Research Council Linkage project, ‘Mountain champions: Building resilient alpine environments with less snow’, led by Dr Susanna Venn of Deakin University and in collaboration with a large group of partners including colleagues from the Australian Mountain Research Facility and La Trobe University, beginning in June 2021.

Within the ASBP, specialist knowledge often exists, and this is freely shared among partners to aid in the germination of ‘nuts that prove particularly hard to crack’ – supplying essential leads that allow the puzzles of seed behaviour to be explored. Now, more than ever, a collaborative approach in ex situ seed conservation is necessary to combat species decline and the aftermath of recent catastrophic events that know no state boundaries. Through the ASBP, greater access to expert knowledge, and techniques, is provided to help seedbanks with the challenges ahead. As we welcome our new VCS team members, we are building more collaborative projects, some of which are now off and running – but stay tuned as there is more to come!

Now, more than ever, a collaborative approach in ex situ seed conservation is necessary to combat species decline.

For more information on ex situ conservation and the Australian Seed Bank Partnership please follow this link: https://www.seedpartnership.org.au/

References

Camac, J., Williams, R.J., Wahren, C.H., Morris, W.K., & Morgan, J.W. (2013). Post-fire regeneration in alpine heathland: Does fire severity matter? Austral Ecology, 38, 199–207.

Driscoll, D.A., Worboys, G.L., Allan, H., et al. (2019). Impacts of feral horses in the Australian Alps and evidence-based solutions. Ecological Management and Restoration, 20, 63–72. https://doi.org/10.1111/emr.12357

Good, R. (1995). Ecologically sustainable development in the Australian alps. Mountain Research and Development, 15(3), 251–258. doi:10.2307/3673932.

Johnston, F., & Pickering, C.M. (2009). Alien plants in the Australian Alps. Mountain Research and Development, 21, 284–291.

O’Donnell, K., & Sharrock, S. (2017). The contribution of botanic gardens to ex situ conservation through seed banking. Plant Diversity, 39(6), 373–378.

Pickering, C.M., Harrington, J., & Worboys, G.L. (2003). Environmental impacts of tourism on the Australian Alps protected areas. Mountain Research and Development, 23(3), 247–254.

Pickering, C.M. (2007). ‘Climate change and other threats in the Australian Alps’ in M. Taylor & P. Figgis (eds), Protected areas: Buffering nature against climate change. Proceedings of a WWF and IUCN World Commission on Protected Areas symposium, 18–19 June 2007, Canberra. WWF Australia, Sydney.

Worboys, G.L., Good, R.B., & Spate, A. (2011). Caring for our Australian Alps catchments: A climate change action strategy for the Australian Alps to conserve the natural condition of the catchments and to help minimise threats to high quality water yields, Australian Alps Liaison Committee, Department of Climate Change and Energy Efficiency, Canberra.

The Gardens

I have a small confession, and I swear that it is true –I would rather visit gardens than visit to the zoo. ( There is nothing wrong with animals, let that be my first remark ), But nothing can compare, for me, with walking in the park. The types of trees are endless, a brilliant splash of scenery, Whether Palms or Ferns or Pines, all dressed in shades of greenery. Grass Trees, Lacebarks, Kapok Trees, all different as can be, And Bottlebrush and Magnolia, and the lovely Chestnut Tree. The blossoms and the flowers, and the Frangipani blooms –The perfumes and the colours would brighten any rooms. Impatiens ( Busy Lizzie ), and Daisies add their flair, And the massed display of Gauras will make you stop and stare. You don’t have to be a botanist to enjoy a garden walk, You don’t need to know the Latin names of horticultural talk. Just look around, and see the plants, and revel in their aura –For nothing could be better when you’re surrounded by the Flora.

Written by: Rod, retiree

Butterfly Bush, or Gaura, at Bundaberg Botanic Gardens.