Fig. 1. The general information of study area. (a) Location of the Mengjiagang Forest Farm (MFF) in the Heilongjiang province, China. (b) Tree species map of MFF. View larger in new window/tab.
Fig. 2. The flowchart of automatic delineation of forest stands based on canopy height model (CHM) and tree species.
Fig. 3. Segments, merged results and final forest stands based on CHM and tree species map. (a) Segments on CHM, (b) Segments on tree species map, (c) The merged segments on CHM, (d) The merged segments on tree species map, (e) The final forest stands on CHM, (f) The final forest stands on tree species map.
Fig. 4. Comparison of delineated forest stands and forest management inventory stands. (a) The final forest stands (red line) and forest management inventory stands (blue line) on CHM. (b) The final forest stands (black line) and forest management inventory stands (blue line) on tree species map.
Fig. 5. The final forest stands of the whole MFF forest farm.
| Table 1. The proportion of Intersection over Union (IoU) > 0.7 and IoU > 0.5 among the stands generated by our stands-delineation method and multiresolution segmentation method with reference stands. | |||||
| Forest stands | Our stands-delineation method | Multiresolution segmentation method | The number of reference forest stands | ||
| The proportion of IoU > 0.7 among the stands (%) | The proportion of IoU > 0.5 among the stands (%) | The proportion of IoU > 0.7 among the stands (%) | The proportion of IoU > 0.5 among the stands (%) | ||
| Forest management inventory stands | 24 | 41 | 46 | 61 | 2285 |
| Logging forest stands | 48 | 67 | 37 | 54 | 148 |
| Forest stands based on Digital Orthophoto Model (DOM) | 64 | 82 | 43 | 55 | 100 |
| Table 2. The explained variance of stand attributes of automatic forest stands and forest management inventory stands. | |||
| Forest stands | Explained variance of mean tree height (%) | Explained variance of mean diameter at breast height (%) | Explained variance of mean canopy height (%) |
| Forest management inventory stands | 96.88 | 97.60 | 74.49 |
| Forest stands by multiresolution segmentation method | 96.77 | 97.61 | 79.67 |
| Forest stands by our method | 97.35 | 97.86 | 81.80 |