Tree Crowns Cause Border Effects in Area-Based Biomass Estimations from Remote Sensing

The estimation of forest biomass by remote sensing is constrained different uncertainties. An important source uncertainty the border effect, as tree crowns are not plot borders. Lidar systems record canopy height within a certain area, while ground-truth commonly aboveground inventory trees geolocated at their stem positions. Hence, reaching out or into observed area contributing to in canopy-height–based estimation. In this study, data and simulations tropical rainforest’s were used quantify amount incoming outgoing volume surface sizes (10, 20, 50, 100 m). This was performed with bottom-up approach entirely based on allometric relationships, from which idealized lidar heights simulated representing 3D voxel space. space, position each known, it also known belongs where located. knowledge analyze role crowns. contribution effects quantified for case small-footprint (a model, CHM) large-footprint (simulated waveforms footprint 23 65 m, corresponding GEDI ICESat GLAS sensors). A strong effect spatial scale found: e.g., 20-m plots, average, 16% CHM belonged located outside 100-m plots fraction only 3%. accounted 40% scale, but had no scale. For GEDI- GLAS-based estimates, contributions 23% 6%, respectively. study presents novel disentangling sources structures using virtual modeling.