Table 1. Comparison of stand characteristics measured in formerly managed beech coppices at the end of the rotation period (27 years) in 1972. The two plots have been started of being converting since 1972 to high forest following two management options: natural evolution (unthinned control) and periodic thinning. For the thinned plot, data are reported, either before (bt) or after (at) each thinning. The reduction in stools and basal area (%) is also reported (brackets); dg: quadratic mean diameter; ddom: top diameter; hdom: dominant height.
ID Inventory Stools Basal area dg ddom hdom
Control 1972 7518 27.4 6.8 18.6 11.2
1982 6846 38.2 8.4 23.0 15.7
1987 3920 40.9 11.5 29.0 20.1
2002 2580 45.3 15.0 33.0 25.1
2012 2046 48.15 17.3 35.2 26.7
Thinned 1972 bt 7407 27.5 6.8 18.6 11.2
1972 at 2222 (–70%) 17.3 (–37%) 9.6 15.9 10.7
1982 2182 29.4 12.8 22.1 15.7
1987 bt 2076 35.2 14.1 24.9 17.6
1987 at 706 (–66%) 19.7 (–44%) 18.8 24.8 17.6
2002 bt 702 33.5 24.6 33.6 24.2
2002 at 414 (–41%) 23.8 (–29%) 27.1 33.5 24.2
2012 412 29.8 30.4 37.5 25.6
Table 2. (Top): Statistics on annual litter production and its partitioning (measured during1992–2014), leaf area index (LAI4; 1999–2014) and canopy transmittance (Trasm; 1999–2014) in control and thinned plots. The number of sampling points in both plots was 9 for litterfall and LAI4 measurements and 36 for canopy transmittance measurements. (Bottom): Growth efficiency estimates obtained after comparison of inventories (1987–2002; 2003–2014) at stand (Estand) and individual tree level (Etree). ∆G: basal area increment between the considered inventories.
Stand ID Litter components (Mg ha–1) LAI4
(m2 m–2)
Trasm.
%
Leaves Woody Nuts Husks Other Total
Control Average 3.785 0.858 0.135 0.331 0.127 5.237 6.1 1.2
SE 0.089 0.081 0.041 0.079 0.031 0.159 0.1 0.2
Min 2.760 0.278 <0.001 0.010 <0.001 3.757 4.5 0.3
Max 4.403 1.640 0.888 1.672 0.481 6.631 7.0 3.0
CV 11.3 45.1 144.5 114.6 116.4 14.5 10.9 59.5
Thinned Average 3.341 0.544 0.115 0.294 0.049 4.346 5.0 4.0
SE 0.132 0.086 0.044 0.085 0.019 0.189 0.2 0.9
Min 1.889 0.097 <0.001 <0.001 <0.001 2.619 2.3 0.4
Max 4.709 1.671 0.982 1.780 0.321 6.311 6.7 16.7
CV 18.9 76.0 183.3 137.9 186.8 20.8 21.1 108.5
 
Stand ID 1987–2002 2003–2014
∆G LAI4 Estand Etree ∆G LAI4 Estand Etree
Control 4.4 5.9 0.74 0.0003 2.9 6.1 0.46 0.0002
Thinned 13.8 5.6 2.47 0.0035 6.0 4.8 1.26 0.0030
1

Fig. 1. Time pattern of total litter (triangles), leaf (squares) and woody (circles) litter production in the beech coppices under conversion to high forests following two management options: periodic thinning (black) and unthinned control (grey). The vertical dashed line indicates the last thinning undertaken in the thinned stand. View larger in new window/tab.

2

Fig. 2. (Left): Time pattern of leaf area index calculated from LAI-2000 PCA (LAI4, excluding the outer ring) in the beech coppices under conversion to high forests following two management options: periodic thinning (black) and unthinned control (grey). The vertical dashed line indicates the last thinning undertaken in the thinned stand. (Right): Time pattern of canopy transmittance in thinned (black) and unthinned (grey) stands from 1992–2014. The vertical dashed line indicates the last thinning undertaken in the thinned stand. View larger in new window/tab.