| Table 1. Summary statistics of the datasets (min; mean; max). | |||||
| Dataset | Number of plots | Tree height [m] | Stem diameter [cm] | Stem volume [m3/ha] | Age [yr] |
| Micro stand and LPM approach | 856* | 3.5;19.2;34 | 4;27.1;67.9 | 1;284;2058 | 10;50;168 |
| Systematic design | 216** | 4.9;18.2;31.6 | 5.2;24.1;51.9 | 2;229;655 | 14;51;160 |
| Evaluation plots | 30*** | 15.8;24;32.4 | 20;30.6;42.3 | 157;360;685 | 33;60;112 |
| * 5 m radius ** 10 m radius *** 40 m radius LPM = local pivotal method | |||||
| Table 2. Summary statistics of the different alternatives (min; mean; max). | |||||
| Dataset | Number of plots | Tree height [m] | Stem diameter [cm] | Stem volume [m3/ha] | Age [yr] |
| S500 | 500* | 3.5;19.2;33.7 | 4;27.1;62.3 | 2;287;2058 | 12;50;131 |
| S250 | 250* | 3.5;19.1;32.3 | 4;26.9;59.7 | 2;276;930 | 13;49;131 |
| S91 | 91* | 3.5;19.3;32.4 | 4;27.7;59.4 | 2;301;1510 | 12;50;131 |
| subS91 | 91* | 3.5;19.6;33.7 | 4;27.7;62.3 | 2;303;2058 | 13;50;100 |
| syst5m | 216** | 4.4;18;37.1 | 4.6;23;51.4 | 3;226;748 | 14;51;160 |
| syst10m | 216*** | 4.9;18.2;31.6 | 5.2;24.1;51.9 | 2;229;655 | 14;51;160 |
| * 5 m radius ** 5 m radius extracted from the 10 m radius plots *** 10 m radius | |||||
| Table 3. Summary of the relative root mean square error (RelRMSE) and relative bias (within parenthesis) values, for the forest variables basal area weighted mean tree height (BWH), basal area weighted mean tree diameter (BWD), mean stem volume per hectare (MSV), basal area (BA) and stand mean age (MA), indicating the accuracy of the airborne laser scanning based imputation of the reference plot data to the 40 m radius evaluation plots for the six different estimated alternatives. | |||||
| Alternative | RelRMSE (%) | ||||
| BWH | BWD | MSV | BA | MA | |
| S500 | 9.6(–6.8) | 8.7(5.7) | 24.7(9.9) | 26.8(17.1) | 21.6(–7.7) |
| S250 | 10.8(–7.8) | 9.0(4.7) | 18.6(–2.1) | 16.2(8.1) | 20.4(–9.6) |
| S91 | 13.6(–9.5) | 10.7(3.4) | 23.3(–3.1) | 20.5(8.5) | 28.7(–13.2) |
| subS91 | 10.6(–7.0) | 11.9(5.8) | 38.8(11.9) | 38.2(19) | 25.0(–7.9) |
| Syst10m | 8.4(–5.6) | 8.0(0.0) | 23.8(–10.6) | 18.3(–8.0) | 20.0(–4.0) |
| Syst5m | 10.1(–8.0) | 8.7(–4.2) | 27.3(–14.9) | 18.3(–8.0) | 23.1(–6.2) |
| Table 4. Summary of error indices of the estimated diameter distributions indicating the accuracy of the estimated diameter distributions using the two different sampling methods, local pivotal method and systematic, with different reference plot intensity. The index value 0 indicates a perfect match of the compared distributions. | ||||
| Alternative | Error indices of the estimated diameter distributions - total variation distance index | |||
| Mean | Minimum | Maximum | sd* | |
| S500 | 0.27 | 0.12 | 0.64 | 0.11 |
| S250 | 0.29 | 0.15 | 0.62 | 0.1 |
| S91 | 0.35 | 0.13 | 0.69 | 0.12 |
| subS91 | 0.35 | 0.2 | 0.54 | 0.1 |
| Syst10m | 0.24 | 0.12 | 0.48 | 0.08 |
| Syst5m | 0.28 | 0.15 | 0.53 | 0.09 |
| * sd: standard deviation | ||||