Table 1. Basic characteristic of analysed stands.
Stand Latitude, longitude
Age
(year) 		Upper stand height
(m) 		Average
(Min – max.) number of trees
(pcs ha-1) 		Mean basal area
(m2 ha-1) 		Average DBH
(±SD)
(cm)
Altitude
(m)
Tipecek 49°19´N, 16°44´E 4 4 42 890
(2000 – 95 000) 		2.8670 0.72
(0.57)
510 5 43 670
(4000 – 99 000)		 4.7680 0.97
(0.66)
Breziny 49°69´N, 18°19´E 8 7 18 720
(6400 – 48 000) 		7.2328 1.89
(1.18)
285 9 18 720
(6400 – 48 000)		 9.8538 2.24
(1.40)
Dubska 49°88´N, 18°10´E 17 15 4720
(2800 – 6400) 		22.0204 7.00
(3.23)
324 18 4720
(2800 – 6400) 		23.3443 7.18
(3.40)
Skrchov 49°59´N, 16°55´E 22 17 2800
(2000 – 3600) 		25.7693 10.20
(3.66)
475 23 2800
(2000 – 3600) 		26.4830 10.33
(3.74)
1

Fig. 1. Location of the experimental stands in the Czech Republic.

Table 2. Estimated parameters (a, b) of biomass equations (Eq. 1) for individual tree components of above-ground dry biomass (AB) of birch. Abbreviations: N – number of sampled tree; R2 – coefficient of determination, SE – standard error of parameter.
      ABtotal ABstem ABbranch
Stand Age N a
(SE) 		b
(SE) 		R2 a
(SE) 		b
(SE) 		R2 a
(SE) 		b
(SE) 		R2
Tipecek 5 37 0.14107
(0.00946) 		2.18716
(0.07429) 		0.980 0.11431
(0.00672) 		2.01210
(0.06639) 		0.981 0.02511
(0.00518) 		2.78590
(0.21770) 		0.917
Breziny 9 36 0.10941
(0.00832) 		2.40663
(0.04607) 		0.993 0.10189
(0.00813) 		2.24554
(0.04897) 		0.990 0.01422
(0.00139) 		2.87939
(0.05751) 		0.993
Dubska 18 8 0.22062
(0.06674) 		2.15318
(0.12325) 		0.993 0.22533
(0.08166) 		2.08008
(0.14806) 		0.989 0.00872
(0.00439) 		2.68412
(0.20206) 		0.989
Skrchov 23 7 0.11792
(0.06954) 		2.40272
(0.23525) 		0.971 0.12251
(0.07621) 		2.35227
(0.24854) 		0.966 0.00192
(0.00104) 		3.05616
(0.21198) 		0.987
Table 3. Mean dry above-ground biomass for individual tree components (AB) (t ha–1) for analysed birch stands (MAI – mean annual increment, CAI – current annual increment).
Stand Tipecek Breziny Dubska Skrchov
Age 4 5 8 9 17 18 22 23
ABbranch 1.39 2.38 3.51 5.54 11.38 12.18 9.07 9.44
ABstem 4.41 6.98 12.23 17.37 75.43 77.92 97.05 99.36
ABtotal 5.80 9.36 15.73 22.91 86.81 90.10 106.12 108.80
MAIABtotal 1.45 1.87 1.97 2.55 5.11 5.01 4.82 4.73
CAIABtotal 3.55 7.18 3.29 2.67
2

Fig. 2. Variability of total above-ground biomass (AB) and its components (stem and branches) within analysed birch stands.

3

Fig. 3. Stem/branch mean AB proportion (%) within analysed stands and ages (numbers inside bars – AB in t ha-1).

4

Fig. 4. Proportion of stem and branch above-ground biomass (AB) of sample trees of analysed stands according to DBH (stem AB – below curves, branch AB – above curves).

5

Fig. 5. Total above-ground biomass (ABtotal) and total dry above-ground biomass mean annual increment (MAIABtotal) in relation to basal area on plots in young and old stands (points represent values on each inventory plot: full circles – ABtotal of young stands, empty circles – ABtotal of old stands, full triangles – MAIABtotal of young stands, empty triangles – MAIABtotal of old stands).

6

Fig. 6. Observed data and models of total above-ground biomass (ABtotal), current annual increment (CAIABtotal), and dry above-ground biomass mean annual increment (MAIABtotal) (points represent values found in observed years).