Ecological Restoration for Mountain Environments

Worshop in the Australian Alps
by Jennie Whinam

A Workshop on Ecological Restoration for Mountain Environments: Approaches and Techniques was held in the Australian Alps in late April. Some 85 attendees got to hear about problems and techniques being used in mountain restoration projects. The final day included papers and a fieldworkshop on restoration of montane peatlands destroyed or degraded in major fires in 2003, led by Geoff Hope, Jennie Whinam, and Roger Good of NSW National Parks & Wildlife Service.

Below an abstract of one of the presentations.

Mire Rehabilitation Programs in montane Australia

by Geoffrey Hope¹ and Jennie Whinam²

Peat swamps have had a bad press, often hinted at in the names given them by stockmen, e.g. Dismal, Rotten, Wambagugga, etc. These gentry liked the fact that moist soils provided edible sedges and grasses in drought time but resented the bottomless muck peats that could bog their cattle, and the inedible mosses and shrubs. Burning and ditching were the main attack tools and a high proportion of the total area of humic soils has been lost in south eastern Australia from burning and humification, even in montane sites now protected from grazing. During the 2003 fires the only area of peatland in the ACT that kept smouldering for several days had been ditched far in the past. Smaller peat fires consumed ditch and incised channel margins that were dry. By contrast, even after months of drought, fire damage to the peat soils in intact mires was very restricted, even where surface vegetation had burnt fiercely. Although charcoal in bog sediments demonstrates a continuous exposure to fire over the past 8000 years, in their un-ditched state mires were intact and able to regenerate from moisture held in the peats. They were resistant to invasion because pH stayed low and waterlogging discouraged generalists. Damage to swamps has accelerated post-European settlement (Hope 2003).

Many plant taxa in peatbogs (eg epacrids) are fire sensitive and do not regenerate readily except from seed while a key taxon, Sphagnum grows very slowly in the absence of shade. Destruction of peat barriers in streamways allows single channels to form and erode, draining small pond systems (staircase ponds, string bogs). Fire thus alters the floristic composition for decades and also changes the physical characteristics of 100% infiltration and substantial short term water storage in cushions and ponds. Sphagnum bogs have been shown to be in a state of retreat throughout the region (Whinam and Chilcott 2002).

Rehabilitation thus must first restore the maximum water retention to the communities and secondly seek to accelerate the recovery of key species of sedges, restiads such as Empodisma and Sphagnum. Steps taken in the ACT and NSW include:

-         Blocking mire “grips” or drainage with sterile straw bales, or mechanical barriers across slopes.

-         Diverting drainage lines onto bog areas and dispersing stream lines

-         Replanting peat fire burn areas with sedge and tussock to impede flow

-         Providing shade to surviving Sphagnum areas

-         Trialling low release fertiliser on moss areas

-         Transplanting Sphagnum divots into moist peats

¹Dept Archaeology and Natural History, Australian National University

²Nature Conservation Branch, Tasmanian Department of Primary Industry, Water and Environment

Hope, G.S. 2003. The mountain mires of southern New South Wales and the Australian Capital Territory: their history and future. Pp 67-79 in J. Mackay and Assoc. (eds.) Celebrating mountains. Proceedings of an International Year of the Mountains Conference. Jindabyne, Australian Alps Liason Committee.

Whinam, J. and Chilcott, N. 2002. Floristic description and environmental relationships of Sphagnum communities in NSW and the ACT and their conservation management. Cunninghamia 7, 463-500.