Effects on stem growth of Scots pine 33 years after thinning and/or fertilization in northern Sweden

Figures & data

Table 1. Starting values before the treatments were executed in 1983 and number and proportion of trees cut during the 1983–2017 period.

Variable	Treatments
	T0F0	T0F1	T1F0	T1F1
DBH 1983, cm	13.6a	13.8a	13.7a	13.8a
Number of stems ha^−1 1983 before treatment execution	1368.5a	1350.9a	1355.6a	1334.3a
Number of stems ha^−1 after treatment execution 1983	1368.5a	1350.9a	738.0b	738.9b
Number of trees ha^−1 cut between 1983 and 2017	210.2a	179.6ab	138.0b	121.3b
Volume cut between 1983 and 1995, m^3	24a	25a	22a	19a

Note: Values not followed by the same letter are significantly different (p < .05).

Figure 1. Volume (m³) as a function of DBH (mm).

Table 2. Values for the calculated variables measured in May (spring) 2017, i.e. after 33 years of growth following the treatments thinning and fertilization, singly and in combination.

	Treatments
Variable	T0F0	T0F1	T1F0	T1F1
Mean DBH, cm	19.4a	19.8a	22.4b	22.7b
Diameter growth 1983–2017, cm	5.8a	6.0a	8.7b	8.8b
Basal area 2017, m^2ha^−1	35.7a	37.3a	24.1b	25.7b
Height 2017, m	20.1a	20.4a	20.1a	20.1a
Crown height, m	12.5a	12.6a	11.2b	11.6b
Standing volume, m^3	257.8a	269.0a	182.7b	195.0b
Volume growth 1983–2017, m^3	142.1a	151.7a	112.2b	124.7b
Volume per tree, m^3	0.14a	0.15a	0.21b	0.23b
Annual growth, m^3ha^−1yr^−1	4.3a	4.6a	3.4b	3.8b
Self-thinning 1995–2017, %	1.4a	1.1a	1.7a	1.5a

Note: Values not followed by the same letter are significantly different (p < .05).