The vulnerability of peatlands in the Australian Alps

Peatlands are coupled to earth's wet climates (Whinam et al. 2003). They are formed when inundated plant material decomposes slowly relative to production, causing partially decayed organic matter to accumulate as soil. A high water table allows non-vascular Sphagnum moss species to prevail in many peatlands. Peatlands promote acidic soil conditions, produce decay-resistant biomass, reduce surface runoff and have an exceptionally high water holding capacity, features which stimulate further peat development. Lowering of the peatland water table can accelerate decomposition and cause a shift away from Sphagnum to shrubs or grass. Hence climatic drying or disturbance causing drainage can compromise organic soil accumulation. Hydrological disturbance from activities such as cattle or horse grazing can also damage peatlands through compaction of peat, increased drainage and runoff and soil erosion.