We evaluated the effectiveness of using the isotopic ratio of 13C to 12C stored in wood, referred to as δ13C, and stem basal area increments (BAI) as indicators of drought in European trees. Using tree ring data from over 3000 trees, we found that while δ13C responded strongly and consistently to drought across a diverse group of tree species and environmental conditions, droughts have small effects on BAI. The results indicate that while δ13C provides a powerful indicator of past drought occurrence, by themselves carbon isotope ratios tell us little about how carbon sequestration and allocation to wood are affected by droughts since most tree species were able to sustain growth even under conditions of low soil water availability.
Jucker, T.; Grossiord, C.; Bonal, D.; Bouriaud, O.; Gessler, A.; Coomes, D.A.
Forest Ecosystems 4 (1), 24