Fire has considerable impact on vegetation and organic soils properties. As we observed that the differences between vegetation of burnt and unburnt areas on the rich fen are visible 11 years after the fire, we assumed that the post-fire changes are long lasting, yet limited exclusively to the burnt areas. In order to check this hypothesis we studied spatial differentiation of physical and chemical properties of soils, and productivity capacities of burnt and unburnt areas in the fen in Biebrza National Park. We took soil samples from the neighboring burnt and unburnt areas, from the depth of 0–30 cm and 30–50 cm. We analyzed 21 parameters of the soils including: pH, ash content, moisture, bulk density, exchangeable K, Na, Ca, available P, N-NH4+, N-NO3−, total N, C, K, Na, Ca, Mg, Fe, P; and calculated C:N, C:P ratios. Surface layer of the burnt soils differed significantly from the unburnt soils in respect of 17 out of 21 parameters. The most pronounced difference was observed for available phosphorous (on average 6 times higher for the burnt soils). The differences in the deeper layer were mostly insignificant. The burnt areas were also characterized by twofold higher plant productivity than recorded for the unburnt areas. The influence of fire on peaty soils was long lasting but mostly limited to the surface layer of the soils. In the case of particular soil features, the post-fire differences were modified by advanced muck formation (moorshing) processes in the unburnt areas. Since the fire led to long lasting increase of fertility, the recovery of fen vegetation is unlikely.

This study proposes the LoRa-Based Mesh Sensor Network without relying on LoRaWAN connection sending the communication data in the form of Star-to-Star, it can be sends the data in the form of peer-to-peer without the gateway. In the case that a longer distance is needed, the system is connected by a means of multi-hop presenting the hardware and software model through the use of low voltage power. Then, the testing is done using point to point and the received signal is measured by a gauge and compared with the model in accordance with the theoretical principle.