*3.1. D Ray Launching Simulations*

The specific scenario under analysis is shown in Figure 12a, and it corresponds to the zoomed area shown in Figure 10 (i.e., measurements zone). The scenario has been created for simulations by the 3D Ray Launching tool. All the materials as well as the real distances and sizes of the surrounding trees have been taken into account in order to obtain accurate estimations of the RF power distribution and therefore, the path loss. Both the material properties and simulation parameters are the same as those used for the isolated tree case, and can be seen in Tables 1 and 2, except the transmitted power, which in this case was 8.35 dBm.

**Figure 10.** Location of the Orgi Forest and its different zones, including the measurement zone (zoomed). Extracted from Google maps.

**Figure 11.** Picture of *Tomaszelaieta* zone within the Orgi Forest.

**Figure 12.** (**a**) Picture of the measurements zone. (**b**) The scenario created for the simulations. (**c**) Detail of the position of the dense vegetation wall.

Figure 12b shows the schematic view of the created scenario for simulation purposes. As can be seen, the morphology and size of each of the single trees surrounding the tree under analysis have been taken into account. In the same way, a specific wall has been created in the scenario in order to model the thick in-leaf trees background that exists behind the tree under analysis (the wall in green in Figure 12c). This wall has been defined with the material Foliage (see Table 1), while the rest have been defined as air.
