Fig. 5. Mean-variance portraits are quantified in terms of characteristics of ecological resilience, particularly by malleability, which is the degree of recovery toward initial conditions (in 1972) after a disturbance. Malleability is calculated by subtracting the mean of the transformed normalized difference index (TNDVI) variance for 1986 and 1987 from the mean of the TNDVI variances for 1984, the disturbance (drought) year.