Radovi, Vol. 48 No. 1, 2022.
Izvorni znanstveni članak
Geospatial analysis of the state of the Marjan Forest Park based on photogrammetric data of the unmanned aerial vehicle
Ivan Balenović
; Hrvatski šumarski institut, Jastrebarsko, Hrvatska
Luka Jurjević
; Geo Unit, Zadar, Hrvatska
Krunoslav Indir
; Hrvatski šumarski institut, Jastrebarsko, Hrvatska
Jasnica Medak
; Hrvatski šumarski institut, Jastrebarsko, Hrvatska
Sanja Perić
; Hrvatski šumarski institut, Jastrebarsko, Hrvatska
Sažetak
In 2017, an intensive wilting and drying of Aleppo pine trees caused by Mediterranean pine engraver (Orthotomicus erosus Woll.) was reported in Marjan Forest Park (Split, Croatia) which intensified and culminated in 2018 and 2019. To prevent further spread of pathogen and decay of trees, sanitary felling of dry and infected trees was conducted in 2019. In order to get a quick and detailed insight into the state of vegetation of the Marjan Forest Park unmanned aerial vehicle (UAV) survey was conducted using a classic photogrammetric and multispectral cameras immediately after the sanitary felling. The main goal was to obtain a current state of vegetation, which will be the basis for the establishment of further monitoring and adoption of timely management activities with the aim to preserve the Marjan Forest Park. Based on UAV data of a very high spatial and spectral resolution, a number of photogrammetric and geoinformation products were created and used for detailed geospatial analyzes of the forest cover of the Marjan Forest Park. This research confirmed the great potential of UAV and used sensors for obtaining quality and reliable information on forests’ state from relatively small areas in a very short time. The results revealed that Marjan Forest Park has satisfactory surface coverage (45%) with vegetation above 5 m in height. However, the surface coverage with vegetation in the range of 2 - 5 m in height is not satisfactory. In the near future this vegetation should take the role of high vegetation (dominant and co-dominant forest layer). Furthermore, two critical areas (13.7 ha) with the highest shares of open areas (areas without vegetation and with low vegetation bellow <5 m in height) were detected. These two areas, therefore, present priority parts of the Marjan Park Forest for rehabilitation and regeneration. Based on calculated NDVI index, it was revealed that 95.5% of canopies of trees above in 5 m in height had satisfactory health condition (NDVI>0.4) in time of UAV survey (August 2019). Visual interpretation of multispectral images revealed a total of 491 remaining dry and chlorophyll-deficient trees. Since these trees are precisely spatially defined, they should be easily find in the field and removed by sanitary felling.
Ključne riječi
tree dieback; Aleppo pine (Pinus halepensis); Mediterranean pine engraver (Orthotomicus erosus); remote sensing; photogrammetry; unmanned aerial vehicle (UAV)
Hrčak ID:
306993
URI
Datum izdavanja:
15.12.2022.
Posjeta: 209 *