Vegetation Effects on the Isotope Composition of Oxygen in Atmospheric CO2

Nature 363, 439-443 (1993) SUBSCRIBERS to Nature in the United States and Canada will have received an incorrect version of this letter, in which colour Figs 2 and 3 have been transposed. In copies of Nature received by the rest of the world, the figures are correct as shown. Also, the symbol á£e used in the first sentence of the second new paragraph on page 442 should be á£r, the oxygen isotope composition of respired CO2.