Fire in the bog: responses of peatland vegetation in the Australian Alps to fire

Abstract

Context Peatlands in the Australian Alps are important ecologically and recognised in national environmental legislation. Increasing fire frequency over the past 40 years has put the community at greater risk of degradation. Aims Using published studies of fire effects in peatlands and new data, we investigate general responses of peatlands to fire so that risk can be evaluated and appropriate management adopted. Methods We present four case studies that employ repeated measures of floristic composition or chronosequences to assess fire-related changes. Key results Cover of frequently-occurring species declined after fire but most had returned to pre-fire cover after 10 years. Recovery of the obligate seeder shrub Dracophyllum continentis (B.L.Burtt) S.Venter and the dominant moss Sphagnum cristatum Hampe was much slower, but variable for the latter, apparently depending on fire intensity and post-fire moisture availability; both species favoured less frequently burnt peatlands with high soil moisture. Some herbs (including non-native species) benefitted from fire, briefly becoming abundant soon afterwards. Overall species richness and diversity were unaffected by fire. Conclusions Peatlands in the Australian Alps tend to be resilient to single fires with effects on species composition being short-lived. However, species cover (especially Sphagnum cristatum) requires perhaps 20 years between fires for full recovery. Fire can cause localised community extinction and this is likely to be exacerbated by other pressures such as trampling and drought. Implications Fire will be difficult to manage in peatlands but resilience might be built by removing other pressures such as trampling by feral animals.