Seeing the wood for the trees: using hazelnuts to reconstruct ancient woodlands

This is based on the fact that hazelnuts which grew in closed environments, such as thick shady forests, have very different carbon isotopes to hazelnuts growing in open, sunny environments. 'Neolithic Nutella'Humans in northern Europe have been using hazel trees as a source of materials and food for thousands of years. The proportions of the different carbon isotopes are altered by the ratio of carbon dioxide concentrations between leaf cells and in the surrounding environment. Where there are fewer other trees to compete for the sunlight and rates of photosynthesis are higher, the hazels will have higher carbon isotope values. Growing changesThe scientists found that nuts from the Mesolithic had been collected from more closed environments, while nuts from more recent periods had been collected in more open environments.