The Database of European Forest Insect and Disease Disturbances: DEFID2

[EN] Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and the conservation of bio-diversity, could be increasingly compromised. Despite the relevance of these detri-mental effects, there are currently no spatially detailed databases that record insect and disease disturbances on forests at the pan-European scale. Here, we present the new Database of European Forest Insect and Disease Disturbances (DEFID2). It comprises over 650,000 harmonized georeferenced records, mapped as polygons or points, of insects and disease disturbances that occurred between 1963 and 2021 in European forests. The records currently span eight different countries and were acquired through diverse methods (e.g., ground surveys, remote sensing techniques). The records in DEFID2 are described by a set of qualitative attributes, including se-verity and patterns of damage symptoms, agents, host tree species, climate-driven trigger factors, silvicultural practices, and eventual sanitary interventions. They are further complemented with a satellite- based quantitative characterization of the affected forest areas based on Landsat Normalized Burn Ratio time series, and dam-age metrics derived from them using the LandTrendr spectral–temporal segmentation algorithm (including onset, duration, magnitude, and rate of the disturbance), and pos-sible interactions with windthrow and wildfire events. The DEFID2 database is a novel resource for many large-scale applications dealing with biotic disturbances. It offers a unique contribution to design networks of experiments, improve our understanding of ecological processes underlying biotic forest disturbances, monitor their dynamics, and enhance their representation in land-climate models. Further data sharing is en-couraged to extend and improve the DEFID2 database continuously. The database is freely available at https://jeodpp.jrc.ec.europa.eu/ftp/jrc- opend ata/FOREST/DISTURBANCES/DEFID2/SIEC Joint Research Centre; European Commission, Grant/Award Number: 101059498; European Research Council, Grant/Award Number: 101039567; Ministry of Research, Innovation and Digitalization of Romania; LifeWatch— POC project, Grant/Award Number: 327/390003/06-11-202

Trhaviny so zvýšenou odolnosťou voči podnetom

Byla zpracována obsáhlá literární rešerše o vývoji LOVA trhavin. Na základě této rešerše byly připraveny modelové trhavinové směsi, u kterých byla pomocí termoanalytických metod určena stabilita, u některých i citlivost ke kompresní rázové vlně.Katedra teorie a technologie výbušninDokončená práce s úspěšnou obhajobo

Who Uses Forest Roads? Has the COVID-19 Pandemics Affected Their Recreational Usage? Case Study from Central Slovakia

Forest roads are necessary to provide access to forests and are also used by users other than forest owners and the timber industry. Their usage for recreation and hiking has been increasing in the last years. From 1/2020 to 12/2020, we performed research on traffic loads and the use of forest roads at an area of the University Forest Enterprise of Technical University in Zvolen. For this purpose, we selected two localities, namely Včelien = A locality and Štagiar = B locality. We monitored transport intensity at selected localities with images obtained from two identical Trail Spromise S308 cameras. We examined the impact of lockdown periods during the COVID-19 pandemics on forest recreation in the year 2020 with the Kruskal–Wallis ANOVA. Multiple comparisons of p values showed there were no differences in the recreational usage of forest roads between the lockdown periods and periods without restrictions. We found that recreation activities peaked in summer and spring. Recreation and transport at selected localities did not have a negative impact on animal occurrence, as the regression and correlation analysis revealed only a low negative relationship with r = 0.029. When considering the number of passages, roads were used for recreation and other non-forestry purposes at approximately 36%. From the perspective of the weight load, recreation accounted for about 10%

Measuring Soil Surface Changes after Traffic of Various Wheeled Skidders with Close-Range Photogrammetry

Soil surface is directly affected by heavy traffic of machinery during harvesting operations. Machine traffic often causes damage to forest soil which is visible on the surface (ruts) and invisible changes in, for example, bulk density, penetration resistance, etc. Close-range photogrammetry is the state-of-the-art method used for recording and evaluation of visible changes. This study aims to analyze soil surface changes caused by traffic of three types of wheeled skidders without a load on Cambisol soil in Central Slovakia. We use the Structure-from-Motion (SfM) close-range photogrammetry to record and evaluate depths of ruts and their volumes after 40 passes of individual skidders. We compared Root Mean Square Errors (RMSEs) of dense point clouds created from various numbers of images taken for individual plots. Rut volume changes calculated by the SfM method and from the manual measurements were compared for one skidder. The final values of RMSE did not exceed 10 mm except for the plot with the lowest number of photos. The final rut depths varied between 0.026 and 0.050 m, and their final volume fluctuated from 0.021 to 0.089 m3. The skidder type and the terrain slope had significant impacts on magnitudes of soil changes. The results of the manual and SfM methods assessing soil changes were correlated. Based on the presented results we can conclude that the SfM method can be applied to detect soil surface changes after traffic of forestry machinery

Deadwood Amount at Disturbance Plots after Sanitary Felling

Deadwood is an important component of forests that fulfils many ecosystem functions. The occurrence, amount and spatial distribution of deadwood in forest ecosystems depend on tree species composition, historical development and past management. In this presented study, we assessed the total amount of deadwood, including fine and coarse woody debris at five areas of predominantly broadleaved forests within the University Forest Enterprise of the Technical University in Zvolen, Slovakia that had been disturbed by windstorm Žofia in 2014. Windthrown wood was salvaged between May 2014 and October 2015. In the year 2018, we performed an inventory of deadwood that remained on-site after salvage logging. The mean volume of deadwood recorded at sample plots fluctuated between 35.96 m3/ha and 176.06 m3/ha and mean deadwood coverage values at individual disturbed areas ranged from 7.27 to 17.91%. In the work, we derived several models for the estimation of deadwood volume based on deadwood coverage and/or diameter, which showed that these characteristics are good proxies of deadwood volume. The tests, involving close-range photogrammetry methods for deadwood quantification, revealed that the number of pieces and the coverage of deadwood recorded in photos was significantly lower than the values derived from field measurements