Author Archives: zwalker

Bushfire in the Victorian Alps

Bushfire in the Victorian Alps

The 2019/20 Black Summer Bushfires, where significant fires were burning in northern and southern NSW, eastern Victoria, South Australia and Western Australia at the same time, has stretched the nation’s resources and capability to respond to such events. A clue to the reason for the extensive fires can be found in the data recorded by the Bureau of Meteorology. Much of eastern Australia in 2019 was:

  1. The driest on record for the three year period January 2017 to December 2019. Mean national rainfall was 100 mm lower than the previous driest three-year period (1965-67).
  2. 2019 was the warmest year on record for Australia.
  3. Severe fire weather conditions (national annual accumulated Forest Fire Danger Index) throughout 2019 were the highest they have been since national records began in 1950.

In Victoria, >1.5M ha of land was burnt, mostly in the east of the State, with profound impacts on many native animals, plants and landscapes.  Some fires did affect alpine areas, including at Mt Buffalo National Park and the Alpine National Park. The extent of fires (at January 2020) is shown below (in red). Importantly, it is obvious that fires have been frequent, extensive and – in some places – repeated since 2003. It is the frequency of fire (what ecologists call the ‘fire return interval’) that will dictate the likelihood of ecosystem recovery. Looking closely at the map, you can see some high mountain areas have been burnt in 2003 and 2020, while others have been burnt in 2013 and 2020, and others near Hotham Heights have been burnt in 2003, 2013 and 2019.

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Fire history map for the Victorian High Country, produced by Thomas Fairman.

Here’s a selection of photos that document the type of burning that has occurred in the Victorian Alps. The RCAAE will be monitoring the recovery of alpine ecosystems – utilising it’s network of long-term plots – to determine the ecological resilience of these areas.

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Burnt heathland and grassland, north of The Horn, Mt Buffalo

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Alpine heathland, grassland and wetland dominated by Sphagnum cristatum has been burnt at Mt Buffalo, south of The Horn

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Forested slopes have been burnt, south of The Horn, Mt Buffalo

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Obligate-seeding shrubs – like Grevillea australis – are killed by fire

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Hovea is a resprouting shrub, recovering from basal buds, Mt Buffalo

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Not all tussock grasses resprout well after fire. Here, Poa clivicola in an alpine grassland at Buckety Plain appears to have died when the canopy is consumed.

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Snowgum forests near Mt Cope have had their heathy understorey consumed by fire. Note the leaves of the trees have been scorched by the heat of fire rather than consumed by fire.

 

Maisie’s Plots, and Long-term Monitoring in the Victorian Alps

Scientific research in the Australian Alps has a long and rich tradition. In 1945, Maisie Carr (nee Fawcett) and Professor John Turner (from the University of Melbourne) established the first long-term monitoring plots in the Victoria Alps at Rocky Valley and Pretty Valley on the Bogong High Plains.

‘Rocky Valley’ is a 5-ha exclosure that was the first permanent plot to be established by Maisie. In January 1945, she selected a large area (a small catchment) on the upper slopes of Rocky Valley that contained a range of vegetation types—mossbed, snowgrass grassland, open heath, closed heath and a Carex-dominated late lying snowbank. A fence was erected to exclude cattle, and a range of permanent plots established to monitor vegetation recovery inside the fence.

‘Pretty Valley’ is a 0.4-ha exclosure (and adjoining control on the edge of the Pretty Valley catchment) that examined the impacts of cattle grazing on range condition in Poa-dominated grasslands. The State Electricity Commission of Victoria erected the fence in 1946 (using the local snow gums for fenceposts) and permanent transects were established. Point quadrats used to assess changes in vegetation composition, ground cover condition, and bare ground.

Pretty Valley Grassland
Fig 1. Maisie Carr’s ‘Pretty Valley Grassland’ plot in 2009. Note evidence of bushfire in the background.

Both plots have been maintained to the present day and are now an integral component of the La Trobe University led Research Centre for Applied Alpine Ecology’s long-term plot monitoring network. Building on Carr and Turner’s work, RCAAE alpine ecologists have expanded the number of sites over the decades to include the wider Victorian Alps. An ongoing surveillance regime examines the impacts of bushfire, introduced ungulates such as sambar deer, exotic plant invasions and climate change on rare species persistence, plant community dynamics, and landscape function.  With a succession of alpine scientists working on an expanding network of permanent plots (today there are more than 50), the value of the RCAAE Plot Network for documenting environmental change is inestimable.

To curate the long-term data, a purpose-designed database was commissioned. With the assistance of La Trobe University’s Department of Computer Science and (partly) funded by the Terrestrial Ecosystems Research Network (TERN; 2012-2017), the database has become the premier repository for long-term scientific data from the Victorian Alps. Over 70 yrs of monitoring at Maisie’s Plots have been captured in the database, providing a record of the sites’ vegetation change, represented by an exceptionally diverse set of population-related observations totalling over 200,000 records. More than 35 yrs of (near) annual population monitoring of the threatened Mountain Pygmy Possum has been entered into the database, along with data on roadside weed invasions, shrub dynamics in open heathlands spanning multiple decades, snowpatch vegetation change since 1992, and microclimate records (including soil and air temperature) since 2003.

Rocky Valley Bog
Fig 2. Maisie Carr’s “Rocky Valley Bog’ plot in 1999, showing the distribution of Sphagnum moss (grey), interspersed with steams and pools (black).

These exceptional data provide an invaluable source of information. “The RCAAE database allows scientists to answer questions about long-term alpine ecosystem dynamics and their vulnerability to changing patterns of climate, fire and land-use pressure,” says Dr John Morgan, member of La Trobe University’s Research Centre for Applied Alpine Ecology. “Getting data into a database is a fantastic achievement, and one that needs ongoing support.”

Long-term research also needs to be supported to provide an evidence base for management decisions. The type of detailed monitoring undertaken in the Victorian Alps allows the RCAAE to anticipate environmental change and to inform how best to manage the land for sustainable use.  According to Dr Dick Williams of Charles Darwin University, and an inaugural RCAAE member, the understanding gained from this research has also highlighted its current limitations. “70 years is a short time in the Alps, and there are still many things we don’t understand. Long-term monitoring will always be vital for increasing our understanding, anticipating change and managing the alpine environment for sustainability.”

Mt Magdala Summit Survey
Fig 3. An example of one of the new plots maintained by the RCAAE – “Mt Magdala Summit Survey Plot’. A network of 14 alpine summits are monitored at 5-yr intervals to assess the effects of climate change, fire disturbance, and exotic organisms on plant community composition and abundance.

The value of long-term research is often under-recognised. But sometimes being present in a landscape and taking repeat measures through time is the most innovative and important thing one can do to understand that landscape, how it is changing, and how it is likely to change in the future. The Australian Alps – small and vulnerable as they are to climate change and exotic invasions – are among Australia’s best monitored ecosystems, and it is from this evidence that trends, trajectories and change can be placed into context. Maisie Carr and John Turner could never have imagined such an enduring outcome of their work when the first fence-post was sunk at Rocky Valley in 1945.

 

For more information on the Victorian Long-term Alpine Plots, please contact Dr John Morgan at alpine.ecology@latrobe.edu.au

 

Maisies Sign

Fig 4. Still going strong. Maisie’s ‘Pretty Valley’ plots are due to be monitored again in 2023. Documenting the ongoing changes in the vegetation inform managers about successional dynamics in alpine rangelands, ongoing effects of drought, as well as providing a means for the early detection of new invasive plant species.

Honours research into the impact that a decline in bogong moth has on mountain pygmy possums

Claire Hutton is a new honours student at at La Trobe University studying with Dr Dean Heinze and Dr John Morgan. Below, Claire has written about her project and motivations for working in the alps.


My interest in the alps originates from two different aspects. Firstly, from a great appreciation for the beauty of mountains. And secondly, from the belief that the management of alpine environments should balance tourist access and the preservation of its ecosystems. My honours project focuses on two major species which rely on the perseverance of Australia’s unique montane conditions: bogong moth and mountain pygmy possum.

Bogong moth migrate in large numbers to the peaks of the Snowy Mountains and the Victorian Alps, including the Bogong High Plains and Mount Buller, every spring. This, in itself, delivers a huge influx of prey to many species, such as mountain pygmy possum. These possums need to gain sufficient weight in the space of only a few months to carry them through their winter hibernation. Traditionally, they do this by capitalising on the extensive bogong moth availability, particularly in October and November; therefore these possums are believed to be dependent on the bogong moth. Over the last two summer, however, there have been anecdotal reports indicating a crash in bogong moth population, raising concern over the impact this decline could have on mountain pygmy possum, among other species.

This study aims to determine both the abundance of bogong moth and the composition of mountain pygmy possum diet, specifically the proportion of bogong moth to other carnivorous and herbivorous prey in faecal samples. This will give insight into the degree of specialisation of these species’ predator prey relationship.

Data collection will take place through field surveys at Mount Little Higginbotham and Mount Buller across the coming snow free season. Specifically, collections will be monthly from October to February capturing the traditional peak in bogong moth alpine population in Spring and allowing for comparisons across early and late summer. Environmental moth abundance will be measured using light traps; diet composition will be assessed through scat collection from possum trapping and subsequent laboratory analysis.

This research may find that moths are not arriving in large numbers. This may reflect the recent drought or agricultural changes in their lowland breeding grounds. This may lead to a reduced proportion of bogong moth being consumed. This study will be able to determine if other arthropods are predated upon in lieu, given that alternative species are available. However, there may be significant impacts on possum health and reproduction if bogong moth cannot be substituted with species which are both available in high numbers and rich in energy.

This study will contribute to records of bogong moth populations as there is currently very limited published data. It will also highlight an additional, potential threat to mountain pygmy possum and the importance of maintaining these ecosystems for supporting the species comprising them.

– Claire Hutton

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Honours student investigating the diet of sambar deer on the Bogong High Plains

Matthew Quin is an honours student currently investigating the diet of Sambar Deer on the Bogong High Plains in Victoria. Although it is recognized that introduced deer cause significant detrimental changes to natural ecosystems, the ability of Sambar deer to aid or limit native and exotic plant species through dietary foraging and endozoochory (the process of moving plant seeds via faecal matter) is still relatively unknown.

Matt is investigating Sambar deer diet through DNA metabarcoding of faecal pellets, an advancing technology used for distinguishing multiple plant species within a sample. Additionally, the role of Sambar deer as plant-seed dispersers will be assessed through glasshouse germination trials of faecal pellets, providing insight into which plant species, whether native or exotic, are capable of surviving the digestive system and prospering from the endozoochory processes of Sambar deer.

Considering threats currently faced by the Victoria Alps as a result of climate change, this project has great importance for understanding additional Sambar deer browsing effects on Bogong High Plains ecosystems, and the prospect of plant species invasion as a result of endozoochory.

Matt Quin and plants germinating from deer pellets

Student Experience: Suzie’s alpine summer studentship

As someone who has grown up surrounded by hills, beautiful views and lush native bush, I thought I knew what I was in for in terms of landscape going into this cadetship despite having spent only a few brief moments in the Australian Alps and barely at all in Summer. I anticipated the beauty, but driving up that endlessly winding road, although reminiscent of the one I grew up on, I realised I had not prepared for just how wondrously captivated I would become over the next five weeks as a cadet with the Research Centre for Applied Alpine Ecology.

The remarkable beauty of the alps added a sense of magic to my entire experience. From long days collecting data for fascinating projects, to shared meals at sunset with some of the most intriguing and quirky (in the best way) people I’ve ever met, to stomping around looking for very discreetly marked plots and weeding Hypochaeris. It was truly extraordinary and influential for me and I am so grateful to have had this opportunity.

I was inspired by every person I met, their passion, knowledge and love for what they do combined with their openness and desire to share that with anyone keen to listen created such a positive environment to learn in. I learnt so many things this summer that it wouldn’t be possible to include them all, but I think one of the most valuable things I learnt was to always ask questions, regardless of whether you’ve asked the same thing 20 times before… usually a bizarre species name. I also learnt the importance of being adaptable when a study design wasn’t suitable or wasn’t going to plan and how crucial a good data sheet can be. This I learnt the hard way, ruling page after page and trying to follow pages crammed with tiny numbers without getting lost.

Another incredible thing I learned was what it is really like to be a researcher, something that I have always been interested in but honestly never thought I would have the opportunity to do. This was really eye opening for me. I always thought that I would love it, and boy was I right. The interactions, intelligence, dedication and genuine fun I observed from this lifestyle was infectious. As a mature age student who swayed from course to course in the past and really struggled with knowing what I wanted to do, this cadetship brought me a sense of clarity and direction that I hadn’t experience before. Although as expected, there were times when I was thoroughly exhausted and even went a little crazy, I quickly realised that this was a quality I shared with my alpine community.

I worked on several different projects, most of which were part of long-term ecological research studies concerned with different aspects of how the alps are changing over time. Some of the main projects being surveys of snow-patches, significant wetlands, populations of invasive weeds and rare species. While data entry and collection are ongoing and analysis is yet to be done, I am enthralled to see what the data we collected tells about the processes happening in this environment, and to get back out there and do whatever I can to help protect this captivating place.

See you soon alps!

– Suzie Moss

Surveying invasive species at Mt Hotham

Suzie surveying the effect of the invasive Ox-Eye Daisy on native flora in subalpine vegetation at Mt Hotham

Snowfence re-visitation studies

 

RCAAE members John Morgan and Susanna Venn recently re-sampled the world’s oldest snowfence experiment at Old Man Range, South Island in New Zealand. Established in 1959 by Sir Professor Alan Mark (University of Otago), the snowfence structure changes the extent and duration of snowcover on a small area of windswept cushionfield. Over time, species composition has changed, as well as species cover. The cushionfield has re-assembled into a snowpatch community dominated by herbs that are rare in the broader cushionfield landscape.  While the accumulation of snow is counter the prediction for many alpine areas (such as Australia – where loss of snowcover is predicted to occur over the coming century), this experiment beautifully illustrates the importance of growing season length and moisture on the distribution of alpine plants. In the Australian context, the loss of snow is likely to lead to the range contraction of species that are restricted to such areas.

Susanna and John will analyse the changes in species composition over time using a plant functional trait approach. What is it about plants – their height, specific leaf area, leaf nitrogen – that allows them to increase in late-lying snowbanks compared to the exposed cushionfields. They will then compare the findings of the Old Man Range snowfence experiment with changes they have been observing at Niwot Ridge in Colorado, USA where a similar experiment has been running since 1994.

snowfence

You can read more about the changes in vegetation at the Old Man Range at:

Mark et al. (2015) Ecological responses to 52 years of experimental snow manipulation in high-alpine cushionfield, Old Man Range, south-central New Zealand. Arctic, Antarctic, and Alpine Research 47, 751-772.