Australasian Plant Conservation

Originally published in Australasian Plant Conservation 18(2) Setember - November 2009, p 13-14

Australian National Botanic Gardens: protecting alpine plants in the face of climate change

Roger Good¹, David Taylor¹, Sarah Fethers¹, Craig Cosgrove¹, Joe McAuliffe¹, Adrienne Nicotra², Kathryn Steadman³ and Gemma Hoyle^2
1 Australian National Botanic Gardens, Canberra, ACT. Email Roger Good: rgo03227@bigpond.net.au ² Australian National University, Canberra, ACT. Email: adrienne.nicotra@me.com ³ University of Queensland, Brisbane, Qld. Email: ksteadman@uq.edu.au

Introduction

Australia’s alpine vegetation (see main picture, front cover) is well recognised for its scientific significance, endemism, species diversity, diversity of origins and its morphological diversity. The Australian Alps are recognised as one of Australia’s 11 centres of plant diversity and one of the world’s 187 biodiversity hotspots. The alpine zone is a small, single, high elevation area in a much larger, low elevation, low rainfall continental landscape, which further enhances the significance of its vegetation.

It is predicted that climate change will have a significant effect on alpine plant diversity and on the structure and function of many alpine plant communities by impacting upon their physiology and timing of life cycles, and on their interactions with other species. This will subsequently lead to the redistribution of alpine plant communities and changes in their structure and composition.

There is now documented evidence to suggest that changing climatic regimes in the Australian Alps over the past 10-20 years have already had significant impacts on the distribution, abundance, life cycles and physiology of a number of alpine plant species. Consequently the Alps biome has been identified as a priority for ecosystem, community and species-specific studies in terms of predicted climate change impacts and the responses of plant species to these changes (Australian Greenhouse Office 2005).

The alpine vegetation and climate change impacts

The predicted impacts of climate change and seasonal shift on the Alps vegetation vary with the species’ life-forms, location in the landscape, sensitivity to small changes in micro-environments, dependence on late autumn and early spring snow cover, as well as changes in total and seasonal precipitation, humidity and temperature (Good 1998; Pickering et al. 2004).

The Alps vegetation also has high levels of biodiversity and endemism due principally to the combination of steep altitudinal gradients, the many micro-climatic sites providing a range of microhabitats, and the evolutionary origins of alpine species.

The current alpine flora reflects a long history of colonisation and speciation events. The species found at high elevations are adapted to alpine conditions including a lengthy winter snow cover. It is expected that species’ capacity to migrate or to move further up the elevation range, as a response to predicted warmer climatic conditions and declining or total loss of snow, is going to be limited. Pressure to colonise a smaller area at higher altitudes will be high and competition intense in an ecosystem where the species have colonised all micro-habitats on all aspects, such that existing populations and communities historically have been relatively stable.

An understanding of the impacts of predicted and identified changing climatic factors in the Alps on the plant phenology, seed production, seed viability and longevity and seed germination of indicator species, is therefore central to developing management strategies to ensure the survival and adaptation of the alpine plant species to future predicted and increasing climate changes.

An exciting new collaborative research program between the Australian National Botanic Gardens (ANBG), Australian National University (ANU), University of Queensland, Royal Botanic Gardens Mount Annan, Centre for Biodiversity Research, Canberra and Kosciuszko National Park, is to commence in October 2009 to address these alpine seed and seedling ecology issues.

Figure 1. Checking plant identification prior to collecting seed samples. Photo: ANBG/David Taylor.

Role of the Australian National Botanic Gardens

The Gardens is the premier national organisation with a long history of growing, studying and promoting Australian native plants. Hence it can play a leadership role in studies aimed at ensuring predicted climate change does not lead to extinctions of native plant species and communities.

In their recent report on the impacts and management of the implications of climate change, Hyder Consulting (2008) noted that the Gardens is ‘ideally placed to respond to this challenge and may play an increasingly important role in ex situ conservation’.

Goal 3 of the National Strategy and action plan for the role of Australia’s botanic gardens in adapting to climate change (CHABG 2008) is ‘to establish a long-term monitoring program of plant responses to environmental change’. The focus of this goal is ‘To monitor the effects of climate change across Australia’s wide variety of ecosystems using the established network of botanic gardens across Australia’. The strategy further states that the Gardens has significant expertise and knowledge of plant flowering and seasonality studies and is well placed to develop methodologies for monitoring the impact of climate change. Goal 4 of the strategy—‘to increase national community awareness of climate change and facilitate effective responses’—gives further support to the Gardens’ role in climate change studies and has specifically been built into the aims of the project (see below).

The Gardens is ideally located to undertake phenological and seed germination trials of alpine species and the subsequent growth of ex situ plants for further morphological and genetic studies. Its staff have already collected seed of some 80 alpine species (Figure 1) and are well placed to commence germination and seed viability studies, as well as the storage of a seed reserve for use in the event of species decline or at worst, species extinctions in the Alps.

Gardens staff already have a close working relationship with management and research personnel in the project’s partner institutions. The Gardens thus is in an ideal situation to co-ordinate the initial collaborative alpine seed viability and germination trials, ex situ plant conservation studies and in situ field plantings for climate change/plant morphology studies, with these institutions.

Seed and seedling ecology project

Currently, there is little knowledge or appreciation of the resilience of alpine plants and plant communities to changes in climatic regimes and seasonal shifts in weather conditions. The purpose of this new collaborative project on seed and seedling ecology is to use detailed ecological and genetic analysis to identify a range of alpine species that may act as indicator species in the Australian Alps, and to determine the impact of future climate change on alpine species and communities.

The project is to commence in October 2009 and will support an ARC postdoctoral fellow program based at the ANU and ANBG and working in collaboration with other partners. The project will also involve post-graduate and honours student research programs. The project will receive funding from a Commonwealth ARC grant and from the Friends of the ANBG, and additional support from the participating organisations. The Friends of the ANBG will also contribute to field activities and assist with laboratory studies.

Links have been established with the Millennium Seed Bank in the United Kingdom to which alpine seed will be supplied for long-term storage.

The aims of the project are:

1. To investigate the germination and dormancy patterns of alpine plant seeds and determine how germination methods can be enhanced; whether physiological dormancy is prevalent among alpine seeds and whether mimicking natural alpine environments can alleviate this dormancy in alpine seeds. This will enable protocols to be developed for the propagation of alpine plants ex situ.
2. To investigate variation in quality and longevity of seeds from alpine plant species in order to optimise protocols for their ex situ conservation.
3. To determine how seed production, seed quality, seedling vigour and recruitment in common alpine species vary along a natural altitudinal gradient and how these traits will be affected by climate change.
4. To assess the role of the maternal environment in determining alpine seed quality, germinability (including dormancy status) and seedling vigour under current and predicted alpine climatic conditions.
5. To develop outreach and interpretive materials including an alpine garden showcasing results and providing opportunity for the general public to learn more about the ecology and management of the Australian Alps flora.

Studies into the maternal effect of environmental factors such as ambient temperature, soil moisture and UV radiation upon seed set, quality and germination will make use of facilities at CSIRO and ANU. The propagation of plants for ex situ conservation and field plantings for in situ plant morphology and growth studies will be carried out at the ANBG nursery.

To compliment the project the Gardens will feature a publicly accessible display and interpretive element as the shopfront for the work. This will be a tool for connecting and engaging people with this and similar projects and more broadly with biodiversity and climate change.

References

Australian Greenhouse Office (2005) Living with climate change. Department of the Environment and Heritage, 36 pp.

Council of Heads of Australian Botanic Gardens (CHABG) (2008). National strategy and action plan for the role of Australia’s botanic gardens in adapting to climate change, Commonwealth of Australia.

Good, R.B. (1998) Changing snow regimes and the distribution of alpine vegetation. In: K.Green (ed.) Snow. A natural history, an uncertain future. Surrey Beattie & Sons, Sydney, 252 pp.

Hyder Consulting (2007) The impacts and management implications of climate change for the Australian Government’s protected areas. Report to Australian Government, 311 pp.

Pickering, C., Good, R.B. and Green, K. (2004) Potential effects of global warming on the biota of the Australian Alps.  Report to the Australian Greenhouse Office, Canberra, 48 pp.

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