Roots of Australian alpine plant species contain high levels of stored carbohydrates independent of post-fire regeneration strategy

Abstract

The relationships between root morphology, level of stored non-structural carbohydrates and post-fire regeneration strategy were investigated in 37 Australian alpine plant species: 6 reseeders, 14 resprouters and 17 capable of both reseeding and resprouting. High concentrations of stored carbohydrate (up to 61.8% DW) were a feature of most species, with more than half of the 37 species containing non-structural carbohydrate concentrations of more than 10%. Fructan was the major reserve polysaccharide in 32 of the 37 species, with particularly high concentrations in the Asteraceae (up to 43.1%). Herbaceous species stored higher concentrations of carbohydrates and had fleshier roots than did shrub species, but swollen underground storage organs were found in only one species (Microseris scapigera sensu Willis1, Asteraceae). There was no significant relationship between post-fire regeneration strategy and either root morphology or level of carbohydrate storage, contrasting with results from drier, Mediterranean environments. Root storage of high levels of carbohydrate, and especially fructan, in Australian alpine species could therefore result from an adaptation to the alpine environment, such as a need for annual regeneration of leaf tissue in alpine conditions.