Vegetation around the ‘Petit menec’ the easternmost menhirs, has reverted to woodland in the absence of biomass reduction.
Ecological burning of grasslands to reduce biomass is an important management tool. Photo: Merri Creek Management Committee.
Intrigued by visual similarities between grasslands in Brittany (France) and near Melbourne, Pascale Pitot and Brian Bainbridge present part deux of an investigation into parallel worlds.
We were captivated by resemblances between people’s traditional relationship to ecosystems, the collapse of these relationships in recent times and counterparts in the emerging recognition and partial revival of traditional practices for the purpose of ecological restoration.
The grassy ecosystems of Brittany and the Victorian Volcanic Plain have been shaped by traditional land management practices of their respective long-term residents. Both grassy ecosystems transform or degrade without periodic intervention such as biomass removal and activities causing soil disturbance. At some stage in the respective histories, human interaction became essential to create the niches required by their characteristic diversity of delicate wildflowers and fauna.
Without slashing or grazing, the heathlands and pastures of Brittany revert to forest, usually via stages of ‘Eagle-fern’ and gorsedominated shrubland. Examples of this process can been seen around the archaeological sites of Carnac in southern Brittany. Traditional techniques (See box 1) prevented this progression and maintained the heathy or grassy cover preferred for grazing. In Carnac, State protection of the archaeological sites dates from 1848 yet traditional grazing among the stones continued through to the later decades of the twentieth century.
Comparable to the grazing and slashing in Brittany, fire was used to reduce biomass of grasslands by the Aboriginal custodians of the Volcanic Plains. It appears to have encouraged food plants and animals but the full sophistication of traditional fire management may never be known due to the swift near-annihilation of the people and their way of life. In the traditional knowledge systems of the Northern Territory, we can get a sense of the many aspects to managing a landscape with fire that may once have been applied in Victoria (for instance see Russell-Smith, Whitehead & Cooke 2009).
Soil disturbance, both human and animal, has also been recognised as integral to the regeneration of plant species at these two ecosystems. In Victorian grasslands, digging for roots and bulbs by Aboriginal people is thought to have fostered establishment plants, including favoured food plants such as Murnong, Microseris spp. In the absence of such fine scale disturbance, regeneration of many forbs has become a rarity. In a parallel example from Brittany, the maintenance of ephemeral wetland areas among heathlands was promoted by ‘etrepage’ (collection of clay for repair of houses) and by the watering of cattle at these wetland areas. The resulting pugging of the soil and retention of open vegetation appear to have been essential for the survival of the (now extremely rare) ‘Panicaut nain vivipare’, Eryngium viviparum.
Over the last two decades there has been emerging recognition of the need to reinstate traditional practices for ecological restoration. After the main archaeological site at Carnac was fenced out in 1991 (officially, to protect the menhirs from erosion due to increasing tourist pressures) the search began to identify an ecological management regime for the vegetation that would both protect the historical values and allow/ guide visitation. For aesthetic, practical and ecological reasons, a low ‘Landes’ (heathland) vegetation was chosen as the target vegetation type. An ecological research project over 10 years carried out by ecologists from l’Université de Rennes trialled different slashing and grazing regimes, with the use of the endangered local breed of sheep. The result was essentially a return to the traditional agricultural management model.
In our grasslands, reintroduction of fire management has been recognised as critical since the early days of modern grassland restoration. More recently investigations at Victoria University have trialled reintroducing the small-scale kinds of soil disturbance that can foster native grassland forbs to re-establish, (relax, it doesn’t involve cows!).
Wherever ecological restoration is being practiced, we have an opportunity to compare practices and perhaps discover new angles of our own.