Silver Fir Defoliation Likelihood Is Related to Negative Growth Trends and High Warming Sensitivity at Their Southernmost Distribution Limit

Table 1

Basal area increment (BAI) mean values and trends measured in declining (defoliation > 50%) and non-declining (defoliation < 50%) trees in the studied stands. Trends values are calculated as the slope of the time series, estimated by least squares regression. Growth reduction percentage is calculated as GRP = 100 × ((mean BAI of the last decade included in the compute) − (mean BAI of the first decade included in the compute))/(mean BAI of the first decade included in the compute). The coefficient of variation (CV) is defined as the ratio of the standard deviation to the mean multiplied by 100. Different letters indicate significant differences based on for one-way ANOVAs.

Tree type	1960–1999 BAI (cm^2)		1960–1999 trend (cm^2 yr −1)		1960–1999 GRP (%)		1960–1999 CV (%)
Nondeclining trees	19.25 ± 1.91	b	0.12 ± 0.11	b	39.11 ± 15.07	b	43.53 ± 2.31	a
Declining trees	15.59 ± 1.79	b	−0.47 ± 0.09	a	−40.74 ± 11.96	a	48.07 ± 3.02	b