Laser Scanning and Aerial Photography with UAV in Studying the Structure of Forest-Tundra Stands in the Khibiny Mountains
Journal Title: Lesnoy Zhurnal (Russian Forestry Journal) - Year 2021, Vol 13, Issue 4
Abstract
Studying the structure of stands is a key point in assessing the role of trees in carbon deposition. Information on the spatial structure of ground vegetation at the upper treeline is still insufficiently presented in modern studies. High resolution remote sensing can provide important data to understand the properties and dynamics of vegetation in these conditions. We test the applicability of ground-based mobile laser scanning of the terrain and aerial photography for the rapid and high-precision assessment of the characteristics of tree stands in the forest-tundra ecotone. We obtained canopy height models (CHMs) of the forest and supplemented them with aerial photographs of the research area on the southeastern slope of the Khibiny Mountains. Using CHMs we have delineated boundaries of tree crowns. The height and projection area were determined for each tree. The first characteristic obtained by laser scanning was compared to the heights of the same trees estimated by field measurements. This was done for the purposes of verification. The comparison revealed that laser scanning data allow to set heights closest to field measurements in case the heights are determined by the maximum values of brightness of pixels of CHMs with manual correction of values when outliers are detected (R2 = 0.84). Since manual correction of outliers is time-consuming, we proposed a way to automate the measurements by determining tree heights using the sum of the average value of pixel brightness and the standard deviation multiplied by 2.5 (R2 = = 0.79). We compared the area characteristics of the stands obtained by laser scanning and the unmanned aerial vehicle (UAV) photography. Thus, we obtained detailed information on the spatial location and size of 4424 trees in an area of about 10 ha and compared the results of measuring tree characteristics obtained by different methods. It was also found that with increasing height from 290 to 425 m above sea level on the studied slope, the average height of stands decreases gradually from 4.5–5.0 to 1.1–1.6 m with small fluctuations (0.2–0.4 m), while the density of stands changes from 4620–5860 to 145 m2/ha in a non-linear way. For citation: Nisametdinow N.F., Moiseev P.A., Vorobiev I.B. Laser Scanning and Aerial Photography with UAV in Studying the Structure of Forest-Tundra Stands in the Khibiny Mountains. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 4, pp. 9–22. DOI: 10.37482/0536-1036-2021-4-9-22 Funding: Data collection and analysis were funded by the Russian Science Foundation, grant No. 17-14-01112; preparation of the text and figures was funded by the Russian Science Foundation, grant No. 21-14-00137.
Authors and Affiliations
N. F. Nisametdinow, P. A. Moiseev, I. B. Vorobiev
Wood Microstructure of Pine Plantations with Different Initial Stocking Rate on Drained Peat Soil upon Fertilization and Herbicide Treatments
To secure a steady operation of large wood processing enterprises in north-west of the Taiga zone, accelerated coniferous forest cultivation appears to be the most promising. Treatments with mineral fertilizers and herbi...
The Use of Logging Machinery Sets in the Republic of Bashkortostan
The disintegration of the integrated logging enterprises, as well as of the forestry enterprises and the reduced attention of the authorities to the production of specialized machinery and equipment, the logging producti...
Dynamics of Understory Vegetation Cover in Anthropogenically Disturbed Pine Cenoses of Krasnoyarsk Forest-Steppe
The dynamics of the understorey vegetation cover in anthropogenically transformed cenoses of common pine (Pinus sylvestris L.) in the period 2017â2020 was studied. The studies were conducted in a diverse herbaceous gro...
Changes in Density and Species Composition of Undergrowth at Different Distances from the Forest Edges in Postagrogenic Areas
The work is devoted to the study of changes in density and species diversity of undergrowth at different distances from the forest edges on postagrogenic lands, as well as factors affecting the distribution of undergrowt...
Detritus Inside High Density Pine Stands in the Taiga Forest-Steppe Subzone of Central Siberia
At the present time, certain harmful effects are observed that affect forest ecosystems. They are forest fires, phytopathogenic activities, and invasive influence, in addition to changes in climatic conditions, in partic...