Natural Radiocarbon Measurements in Brazilian Soils Developed on Basic Rocks

Abstract

This paper presents 14 C, 13 C and chemical data of soil organic matter (SOM) in three soil profiles under native forests from Brazil: Londrina (southern), Piracicaba (southeastern) and Altamira (northern). The main objective is to use carbon isotopes in tropical and subtropical soils of Brazil to provide information about vegetation changes that occurred in relation to climate changes during the Holocene. 14 C data from SOM indicate that the organic matter in the soils studied is of at least Holocene age. 13 C data indicate that C 4 plants probably provided the dominant vegetation in Londrina and Piracicaba during the early and mid-Holocene and that C 3 plants provided the dominant vegetation in the Altamira region during the Holocene.