Fig. 1. Height (A) and diameter at breast height (DBH) (B) of fertilized and control Norway spruce in winter of 2012 at the age of 34 years. Line shows median, box represents 1st and 3rd quartile, whiskers mark range (not exceeding 150% of interquartile distance) and circles denote outliers of the datasets.
Table 1. Statistics of treering parameters (minimum (MIN), maximum (MAX) and mean (MEAN) values and their standard deviation (SD) and coefficient of variation (VAR)) of crossdated datasets and pvalues of differences (DIFF) in mean values of mean time series of treering parameters of fertilized and control Norway spruce in Kalsnava, Latvia. 
 MIN  MAX  MEAN  SD  VAR  DIFF 
Maximum density, kg m^{–3} 
Fertilized  258  1087  832  128  0.15  
Control  376  1061  811  116  0.14  < 0.01 
Mean density, kg m^{–3} 
Fertilized  170  713  489  82  0.17  
Control  144  760  495  86  0.17  0.69 
Mean earlywood density, kg m^{–3} 
Fertilized  84  638  400  86  0.22  
Control  39  649  399  96  0.24  0.42 
Mean latewood density, kg m^{–3} 
Fertilized  229  931  692  113  0.16  
Control  276  881  672  108  0.16  < 0.01 
Treering width, mm 
Fertilized  0.59  9.20  3.54  1.65  0.47 

Control  0.37  9.85  3.37  1.54  0.46  0.65 
Proportion of latewood 
Fertilized  0.06  0.88  0.32  0.15  0.49  
Control  0.05  0.94  0.37  0.16  0.45  < 0.01 
Table 2. Pearson correlation (r) and Gleichläufigkeit (GLK) coefficients calculated between mean time series of crossdated datasets of treering parameter of fertilized and control Norway spruce in Kalsnava, Latvia for 1987–2013. 
 r  GLK 
Maximum density  0.40  0.77 
Mean density  0.70  0.81 
Earlywood density  0.66  0.69 
Latewood density  0.53  0.55 
Treering width  0.88  0.81 
Proportion of latewood  0.80  0.58 
Fig. 2. Mean measurement (treering width (A); proportion of latewood in treering (B); maximum (C) and mean (D) wood density of treering; earlywood (E) and latewood (F) density) time series and sample depth (G) of fertilized (black line) and control (grey line) Norway spruce. Asterisks indicate significance (pvalue < 0.05) of differences between fertilized and control trees.