Can we infer vegetation change from peat carbon and nitrogen content? A palaeoecological test from Tasmania, Australia

We set out to test the ability to detect vegetation change from organic soil nutrient (carbon and nitrogen) composition in the fire-determined forest/non-forest mosaic of western Tasmania, Australia. We find no relationship between organic soil nitrogen and carbon content, despite widely varying local vegetation and fire regimes. Pollen evidence supports the role of fire in driving an initial vegetation state change from forest to non-forest, while carbon and nitrogen analysis of the peat section suggest that factors other than peat nutrient (carbon and nitrogen) content are responsible for the observed meta-stability of non-forest at the site for 7000 years. We find that we cannot validate the use of organic soil nitrogen and carbon content for inferring vegetation type and question the degree of post-European vegetation change inferred from this method.