Table 3 Comparisons of mean productivity (t ha−1 yr−1) and final total biomass (t ha−1) at the stand level between mixed stands and pine monocultures and between pines in the mixed stands and pine monocultures, according to plot density, and net biodiversity effect (NBE) calculated for each density. The calculation description uses the terminology presented in Fig. 1: M1500 and M750 (mixed stand at 1500 and 750 stems/ha density respectively); P1500, P750, and P375 (pine monoculture at 1500, 750, and 375 stems/ha respectively); P mix1500 and P mix750 (pine trees in mixture at 1500 and 750 stems/ha respectively with a pine density of 750 and 375 respectively). The net biodiversity effects (NBE) NBE1500 and NBE750 correspond to the yielding calculated for mean productivity at 1500 and 750 stems/ha respectively. TY transgressive yielding. Please note that yielding (TY, NBE) values are not usually calculated for biomass
Initial mixture total density | 1500/ha | 750/ha | Â | |||||
|---|---|---|---|---|---|---|---|---|
Calculation | M1500-P1500 | M1500-P750 | Pmix1500-P750 | NBE1500 | M750-P750 | M750-P375 | Pmix750-P375 | NBE750 |
Substitution (TY) | Addition (plot) | Addition (pine) | Substitution (NBE) | Substitution (TY) | Addition (plot) | Addition (pine) | Substitution (NBE) | |
Mean productivity (t/ha/year) | − ;1.14/− ;9.5% | + ;0.19/+ ;1.6% | − ;0.04/− ;0.1% | + ;3.9 | − ;2.43/− ;25.9% | + ;0.72/+ ;7.7% | + ;0.41/+ ;4.5% | + ;2.8 |
Total biomass (t/ha) | − ;3.94/− ;0.9% | − ;0.59/− ;0.1% | − ;1.71/− ;0.4% | + ;168.6 | − ;63.69/− ;18.4% | + ;27.99/+ ;8.8% | + ;21.44/+ ;6.3% | + ;122.1 |