Submission to the Alpine Grazing Taskforce, Victoria

June 2004

Professor David Gillieson
Chair, National Committee for Geography
Australian Academy of Science
Ian Potter House, Gordon Street, 
Canberra 2601

Introduction
The National Committee for Geography of the Australian Academy of Science is pleased to make a submission to the Alpine Grazing Taskforce regarding cattle grazing in the Alpine National Park of Victoria. The Academy made an earlier submission on this and related issues:

Australian Academy of Science (1957). “A report on the condition of the high mountain catchments of New South Wales and Victoria”. Australian Academy of Science, Canberra.

This landmark document distilled the best available scientific evidence at the time, and had influence on legislative change which protected the nature conservation values of alpine areas, as well as mitigating the downstream effects of alpine grazing on water quantity and quality. The issues, in terms of ecology and economy, have not changed, though in 50 years acres have become hectares, miles kilometers and pounds dollars.

The issue of cattle grazing in the Victorian alpine and sub-alpine ecosystems involves three factors: their suitability for livestock production in competition with other land uses; the effects of grazing on the hydrology of these ecosystems, and the downstream effects; and the effects of grazing on nature conservation values. Each is important and needs to be viewed in wider perspective. Over five decades of research has shown that grazing and nature conservation in alpine areas are essentially incompatible land uses. The continuation of grazing within any of the Victorian alpine and sub-alpine national parks is at variance with established concepts and values of nature conservation.
Impacts of cattle grazing in the Alpine National Park
In Victoria approximately 8000 head of cattle currently graze some 60 licenced areas in the Victorian Alpine National Park, between December and March each year. About two thirds of these graze alpine/high subalpine country, principally in the Holmes/Wellington Plains, Bogong High Plains, Dargo High Plains, and Cobberas areas. 

Present and past grazing and trampling by domestic livestock have altered the patterns of disturbance in high mountain ecosystems of Australia. Alpine humus soils and associated vegetation can be disturbed by accelerated erosion due to increases in the proportion of bare ground. Cattle can trample the vegetation, increasing the amount of bare ground within most plant communities. Cattle tracks can also act to channel water flows on slopes, whereas in unmodified communities dense tussock grasses disperse water flows. The grassland, wetland and snow patch communities have been particularly modified (Wimbush and Costin 1979; Wahren et al. 1994; Williams et al. 2003). These demonstrated changes prompted the gazettal of a number of alpine national parks for both nature conservation and catchment protection.

Wetland communities are very susceptible to trampling damage, because both the peaty soils and Sphagnum moss patches are relatively soft. Reduction in the area of Sphagnum moss patches changes the hydrologic regime, releasing large volumes of water in a short time. Stream entrenchment can now be observed in many alpine areas of Australia, with a consequent increase in erosion potential (Wimbush and Costin 1983; Wahren et al. 2001a). Wetland areas excluded from cattle grazing on the Bogong High Plains since 1980 have shown a substantially greater rate of recolonization of exposed soil than areas to which cattle have had continued access (Wahren et al. 2001a). In snow patch herbfields, where slopes are steep and soils remain moist until well into the growing season, cattle grazing and trampling can increase the amount of bare ground substantially, from less than 2% to more than 20% (Wahren et al. 2001b).

Stock grazing has affected the composition of the native alpine and subalpine vegetation because the animals are free-ranging, are fairly selective in both the communities in which they graze and the species upon which they feed (van Rees and Hutson 1983). Cattle prefer to graze within the open grassy communities, as the biomass availability of the more palatable species is greater in these communities than in the closed heaths. Palatable species within grassland and open heath include grasses, e.g. snow grasses (Poa spp.), major dicot herbs such as Celmisia and Craspedia, and some small- to medium-sized shrubs such as Asterolasia trymalioides and Grevillea australis. Long-term exclusion plots established at Pretty Valley in the 1940s have shown clearly that, in the absence of grazing, the abundance of many of these palatable species has increased substantially. In contrast, most shrubs in both open heath and closed heath, such as Hovea longifolia and the taller  shrubs such as Prostanthera cuneata, Phebalium squamulosum and Orites lancifolia are non-palatable. Long-term monitoring of shrub cover in reference heathland areas where these shrubs predominate has shown no effect of grazing on the cover of these shrubs (Wahren et al. 1994; Williams et al. 1997).

The structure of heathlands and grasslands may also be altered by cattle activity. In a number of areas shrubs have invaded grassland and herbfield. Shrub invasion is facilitated by patches of bare ground on which seedlings may establish. Grazing manifestly increases the abundance of bare ground patches, and hence facilitates shrub establishment. Where non-palatable shrubs have established, they have invariably increased in cover because they are not browsed and also resprout vigorously from dormant buds after trampling. Such shrubs are therefore persistent in the alpine landscape. Where palatable shrubs such as Asterolasia have established, their subsequent growth may be inhibited by grazing as they are both browsed and incapable of resprouting if trampled, as they regenerate from seed and lack dormant buds (Williams and Ashton 1987b, 1988; Williams 1990).

Grazing and fire
In the wake of the 2003 bushfires in southern Australia there were numerous claims in the media that fires burnt less intensely in grazed alpine areas, and that grazing is essential to protect the alpine landscape from the effects of fire. Does the existing body of scientific data support these claims? Moreover, what are the effects of introduced livestock on burnt alpine country? The existing research base on interactions between grazing and vegetation dynamics, and preliminary observations of the patterns of burning on the Bogong High Plains, shed light on these questions.

A study on the diet and behaviour of cattle (van Rees & Hutson 1983) showed that cattle prefer open grassy communities, but avoid the dense, closed heath communities. By avoiding the closed heaths, cattle are avoiding the most flammable components of the alpine landscape.

Heathlands clearly burnt more severely and extensively than the grasslands in the 2003 fires (Williams, 2003). Moreover, the general pattern of burnt heath abutting unburnt grassland, and evidence of fires having jumped, sometimes one hundred meters or more, between patches of closed heathland, over grassland, appear to be just as common in grazed areas (e.g. Rock Valley) as ungrazed areas (e.g. Heathy Spur). Minimum twig diameter of burnt shrubs is a measure of fire intensity/severity – the bigger the minimum diameter of burnt twigs, the more severe/intense the fire at the site of the shrub (Whight and Bradstock 1999). Two species were examined -  Grevillea australis within open-heath and Orites lancifolia  in closed heathland -  at a number of burnt locations on the Bogong High Plains (both grazed and ungrazed). The data – some 2000 individual twig measurements - showed no difference between grazed and ungrazed sites for either species in this indicator of fire severity (Williams, 2003).

Therefore, any fuel reduction effect of grazing within grasslands is likely to be occurring in the least flammable part of the landscape (Williams 2003). While reductions in grass cover and biomass will naturally result in localized reductions in fire intensity, all other factors affecting fire behaviour being equal, it is not known whether such localized effects would necessarily translate increased suppression capacity at a landscape scale. Given the inherently lower flammability of grasslands compared with heathlands, and the apparent capacity of fires such as the 2003 fires to jump between patches of heath, over bands of grassland tens and even hundreds of meters wide, then there must be doubts about the effectiveness of alpine grazing as a fire management tool at the landscape scale.

The primary effects of stock grazing on burnt alpine landscapes are to slow the rate of vegetation regeneration, and thus increase the risk of land degradation following thunderstorm rains. Natural values of the alpine region are maintained by a high level of dense vegetation cover and fixed litter, and minimum levels of bare ground. The risk of land degradation increases as vegetation cover declines and the proportion of bare ground increases. Grazing by its nature reduces vegetation cover and increases bare ground. The effects of fire and grazing by introduced livestock as determinants of land degradation in Australian alpine ecosystems have been well known for many decades (Australian Academy of Science 1957; Costin et al. 1999; Williams et al. 2003).

Climate change
Global warming has a great potential capacity to cause unwanted change in the Australian Alps. Warming of the alpine landscapes is very likely, yet the potential impacts are very poorly understood. Globally, the potential impact of rising temperatures is predicted to be strongest at both higher altitude and latitude (IPCC 2001). The alpine vegetation zone in Australia is small in extent compared with that of most high mountain areas of the world, with limited high altitude refugia (Costin et al. 1999). Hence, the impact of climate warming on Australian alpine ecosystems could be greater than elsewhere, as the alpine zone may retract substantially, or simply disappear (Hughes 2003). A plausible climate change scenario for south-eastern Australia is a 1-2o C rise in mean annual temperature, and decreased winter precipitation (Hughes 2003). This will cause the snowline and the upper treeline to retreat upwards by several hundred metres (Galloway 1988), and alpine grassy vegetation will be more susceptible to invasion by woody species.

There is some evidence that climate change and associated ecological responses have already commenced in the Australian Alps. Snow cover has declined in the past 10 years (Osborne et al. 1998). Seedlings and saplings of snowgum (E. pauciflora) from the subalpine woodland zone are encroaching on alpine and subalpine treelees herbfields (Wearne & Morgan 2001), and there have been significant contractions in the range of some rare and threatened vertebrates such as the Corroboree Frog (Green & Pickering 2002).
Conclusions
The alpine and subalpine ecosystems of Victoria are restricted in area but constitute a valuable resource for nature conservation, ecotourism and ecosystem services. All the ecosystems are important for catchment protection. The alpine vegetation is a patchy mosaic of woody and grassy communities, whose persistence is determined by complex interactions between microclimate, natural and human disturbance, and the reproductive strategies of plant species  
Grazing by domestic cattle may alter the composition and structure of most vegetation types. Fire is naturally rare in these environments, and there is little scientific evidence that grazing reduces fuel loads in the most flammable parts of the landscape. Current and continued grazing by cattle in the alpine vegetation, especially where burnt, is incompatible with the maintenance of nature conservation values and ecosystem services. Global warming will have potentially serious effects on all Australian alpine landscapes, yet the ecological responses to warming and options open to land managers to mitigate the effects of rising temperatures, are very poorly understood. Research into the effects of climate change on Australia's fragile apline environments should receive increased and urgent attention under the federal government's national research priority for an environmentally sustainable Australia.
Acknowledgements
We are grateful to the following individuals for publications and scientific advice: Dr Dick Williams, CSIRO Sustainable Ecosystems; Professor Jamie Kirkpatrick, University of Tasmania.

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