Extended Data Fig. 9: An example of decrease in drought resistance with increase in drought severity.

A tree-ring site (32.43°N, 110.79°W, Ponderosa pine) in Arizona, USA presents a decrease in drought resistance with increase in drought severity during three periods (i.e. 1950-1969, 1970-1989, and 1990-2009). The name of the tree-ring site is az598 in the ITRDB tree-ring database. Blue bars (upper panel) denote the mean drought severity during each period and orange bars (lower panel) denote the mean resistance during each period. Arrows show the directions of changes in drought severity (blue) and resistance (orange) over time.