Century-scale environmental reconstruction by using stable carbon isotopes: just one method from the big bag of tricks

Abstract

The field of 'historical ecology' is coming to maturity at a time when we, in Australia, are reflecting on our relationship with, and place in, the land. After an essentially ahistorical approach to land use we are now attempting to place land management into the context of environmental change since and immediately preceding Western European settlement. This volume reflects an emerging concern that, collectively, non-indigenous Australians have no 'environmental history'. One component of 'living in' rather than 'battling against' the land is developing a sense of our history. Without an oral narrative that is commonly shared, attempts to develop the story of environmental change have to be based on retrospective and reconstructive research. This volume captures part of this movement to develop an environmental narrative and context for our future relationship with the land. There are many methodological approaches to reconstructing a story of the past, from local knowledge and oral history to the 'high-tech' and hard sciences. This paper reviews methods that apply stable carbon isotope techniques to reconstruct environmental change. Although well suited to environmental history, carbon isotope techniques remain under-utilised in the Australian context. Here I review applications to highlight the strengths and limitations of carbon isotope techniques in the reconstruction of century-scale vegetation change. There have been two dominant applications of carbon isotope techniques to environmental reconstruction. These applications fall broadly into either stable carbon isotope analysis of organic matter in soils and sediments, or inferences of environmental states have been drawn from carbon isotope analysis of animal tissues and residues. The main strength of stable carbon isotope techniques is that they can be spatially precise while integrating a range of environmental information into one isotopic signal. This integrative strength is at the same time one of the major limitations of carbon isotope techniques because floristic (taxonomic) resolution is low.