The bark beetle Taphrorychus bicolor primarily inhabits Fagus sylvatica forests. Its populations increase after periods of drought. Due to the limited knowledge of factors affecting its abundance, we conducted a large-scale sampling. Beetles were captured using three Theysohn traps lured with bicolorin at 26 study sites in mature homogeneous beech forests distributed throughout the Czech Republic. The traps were checked, and beetles were sampled weekly or biweekly in 2022. Using Generalized Linear Mixed Models (GLMMs), the impact of selected environmental and management variables on the abundance of T. bicolor was analyzed. The species occurs at elevations ranging from 150 m a.s.l. to 1300 m a.s.l. throughout the Czech Republic. This represents its entire host range, e.g., beech, although in the lowest elevations it is also found on other deciduous trees. In 2022, the flight activity lasted from late April to early September, and two generations were recorded, with the filial generation starting to fly in late June. In many study sites, more than 10,000 beetles were captured per trap. The number of females trapped was higher than males, consistent with the species' polygamous strategy, where females move toward increasing concentrations of pheromones. The number of beetles in the traps was influenced by elevation, with the highest abundance observed at around 600 m a.s.l. Abundances were higher in areas with more extensive beech forest complexes. Lower beetle abundances were found in stands where the studied forest bordered with meadows, pastures, or crop fields, indicating the species' reluctance to fly outside the forest habitat. The abundance of the filial generation was higher when there was a larger area of beech forests within a 1000 m radius, suggesting a median dispersal flight distance of approximately 1 km for the filial generation.

Forest fires significantly disrupt global ecosystems. Many forecasting techniques predict fire activity and allocate prevention resources, but various factors are missing from the assessments, and multi-criteria decision approaches alone are insufficient. This work introduced a novel methodology combining artificial neural networks (ANN) with the analytical hierarchy process (AHP), fuzzy AHP multi-criteria methods, and spatial data to detect potential forest fire vulnerability areas using twenty variables. The results from AHP or fuzzy AHP, were processed using a multilayer perceptron with a backpropagation algorithm. The final ANN model has two objectives: first, to create a forest fire vulnerability with four classes (low, moderate, high, and very high), and second, to classify burned area sizes in regions highly or very highly vulnerable to fire. Evaluation metrics were also applied for validation. The fire model was tested using both literature review data and in situ observations. Comparative analysis showed that the burned area size model performed better than other machine learning methods, achieving an accuracy score of 89%. Meanwhile, the fire vulnerability model scored 82%. The study addresses the problem of prediction and provides an algorithm for classifying fire risk based on historical data in the Czech Republic, offering a master model for future forest management. Therefore, the ANN model, once trained, validated, and tested, does not require resetting and is effective for estimating forest fire vulnerability. Moreover, it produces results quickly, providing rapid insights into complex forest ecosystems, saving time and enhancing understanding for decision-makers.

Central Europe is not a typical wildfire region; however, an increasingly warm and dry climate and model-based projections indicate that the number of forest fires are increasing. This study provides new insights into the drivers of forest fire occurrence in the Czech Republic, during the period 2006 to 2015, by focusing on climate, land cover, and human activity factors. The average annual number of forest fires during the study period was 728, with a median burned area of 0.01 ha. Forest fire incidence showed distinct spring (April) and summer (July to August) peaks, with median burned areas of 0.04 ha and 0.005 ha, respectively. Relationships between the predictors (climate data, forest-related data, socioeconomic data, and landscape-context data) and the number of forest fires in individual municipality districts were analyzed using Generalized Additive Models (GAM) on three time scales (annually, monthly, and during the summer season). The constructed GAMs explained 48.7 and 53.8% of forest fire variability when fire occurrence was analyzed on a monthly scale and during the summer season, respectively. On an annual scale, the models explained 71.4% of the observed forest fire variability. The number of forest fires was related to the number of residents and overnight tourists in the area. The effect of climate was manifested on monthly and summer season scales only, with warmer and drier conditions associated with higher forest fire frequency. A higher proportion of conifers and the length of the wildland–urban interface were also positively associated with forest fire occurrence. Forest fire occurrence was influenced by a combination of climatic, forest-related, and social activity factors. The effect of climate was most pronounced on a monthly scale, corresponding with the presence of two distinct seasonal peaks of forest fire occurrence. The significant effect of factors related to human activity suggests that measures to increase public awareness about fire risk and targeted activity regulation are essential in controlling the risk of fire occurrence in Central Europe. An increasing frequency of fire-conducive weather, forest structure transformations due to excessive tree mortality, and changing patterns of human activity on the landscape require permanent monitoring and assessment of possible shifts in forest fire risk.

The bark beetle Taphrorychus bicolor primarily inhabits Fagus sylvatica forests. Its populations increase after periods of drought. Due to the limited knowledge of factors affecting its abundance, we conducted a large-scale sampling. Beetles were captured using three Theysohn traps lured with bicolorin at 26 study sites in mature homogeneous beech forests distributed throughout the Czech Republic. The traps were checked, and beetles were sampled weekly or biweekly in 2022. Using Generalized Linear Mixed Models (GLMMs), the impact of selected environmental and management variables on the abundance of T. bicolor was analyzed. The species occurs at elevations ranging from 150 m a.s.l. to 1,300 m a.s.l. throughout the Czech Republic. In 2022, the flight activity lasted from late April to early September, and two generations were recorded, with the filial generation starting to fly in late June. In many locations, more than 10,000 beetles were captured per trap. The number of females trapped was higher than males, consistent with the species' polygamous strategy. The number of beetles in the traps was influenced by elevation, with the highest abundance observed at around 600 m a.s.l. Abundances were higher in areas with more extensive beech forest complexes. Lower beetle abundances were found in stands where the studied forest bordered permanent non-forested areas, indicating the species' reluctance to fly outside the forest habitat. The abundance of the F1 generation was higher when there was a larger area of beech forests within a 1000 m radius, suggesting a median dispersal flight distance of approximately 1 km for the F1 generation.

Forest fires are becoming a more significant problem in Central Europe, but their danger is not as high as that in Southern Europe. The exception, however, is forest fires occurring in disturbed areas (windthrow and bark beetle outbreak areas), which are comparable in severity and danger to the most serious forest fires. In this study, we describe the current situation in Central European countries in terms of fire protection for disturbed areas in managed forests and forest stands left to spontaneously develop (secondary succession). If a country has regulations and strategies in this area, they are often only published in the local language. In this review, we combine information from all Central European countries and summarize it in a unified international language, provide an opportunity for local authorities to express their own experiences, and integrate data from worldwide scientific research. Thus, this paper may be considered a universal guide for managing fire protection and preparedness in disturbed areas and can serve as a reference for the establishment of strict legislative rules at the state level. These laws must be obligatory for all stakeholders in individual countries. The motivation for this study was two large forest fires in an area left to spontaneously develop in the Bohemian Switzerland National Park in the Czech Republic and Harz Mountains in Germany in the summer of 2022. These incidents revealed that fire prevention legislation was inadequate or nonexistent in these areas. The strategy of the European Union is to increase the size of protected areas and spontaneous development areas. Therefore, we consider it necessary to provide governments with relevant information on this topic to create conditions for better management of these destructive events.

Abstract Background The vulnerability of forests to fire results from complex interactions among climate, fuel availability (fuel load and moisture content of the vegetation), and ignition sources. The number of forest fires (FFs) has increased in many regions, therefore, it is necessary to reduce and monitor the fire risk. Based on data from 2006 to 2015, we used Generalized Additive Models to determine the degree to which local climate, the forest–urban interface, the percentage of conifers, the number of overnight tourists, and the number of local human inhabitants (residents) are related to the FF frequency in the Czech Republic (Central Europe). Results On a monthly scale, the FFs incidence showed distinct spring (April) and summer (July-August) peaks. No distinct pattern was identified on an annual scale, yet the highest number of FFs occurred in 2015, the hottest year in our records. The used predictors explained 45 and 46% of the variability in FFs on monthly and summer scales, respectively, and 69% on an annual scale. The number of FFs was related to the number of residents and the number of overnight tourists ha− 1 y− 1 of the forest. The effect of climate was manifested on monthly and summer scales only, with warmer and drier conditions associated with higher FF frequency. A higher proportion of conifers and the length of the forest-urban interface were positively associated with FF too. Finally, FF frequency was associated with the population density and number of overnights, suggesting the importance of human behavior in fire risk. Conclusions The significant relationships between the numbers of FFs and the number of residents and overnight tourists ha− 1 y− 1 of forest suggest that the risk of FFs could be controlled by increasing public awareness and implementing stricter regulations on tourist and local inhabitants’ behaviour.

Over the last decades, the natural disturbance is increasingly putting pressure on European forests. Shifts in disturbance regimes may compromise forest functioning and the continuous provisioning of ecosystem services to society, including their climate change mitigation potential. Although forests are central to many European policies, we lack the long-term empirical data needed for thoroughly understanding disturbance dynamics, modeling them, and developing adaptive management strategies. Here, we present a unique database of >170,000 records of ground-based natural disturbance observations in European forests from 1950 to 2019. Reported data confirm a significant increase in forest disturbance in 34 European countries, causing on an average of 43.8 million m3 of disturbed timber volume per year over the 70-year study period. This value is likely a conservative estimate due to under-reporting, especially of small-scale disturbances. We used machine learning techniques for assessing the magnitude of unreported disturbances, which are estimated to be between 8.6 and 18.3 million m3 /year. In the last 20 years, disturbances on average accounted for 16% of the mean annual harvest in Europe. Wind was the most important disturbance agent over the study period (46% of total damage), followed by fire (24%) and bark beetles (17%). Bark beetle disturbance doubled its share of the total damage in the last 20 years. Forest disturbances can profoundly impact ecosystem services (e.g., climate change mitigation), affect regional forest resource provisioning and consequently disrupt long-term management planning objectives and timber markets. We conclude that adaptation to changing disturbance regimes must be placed at the core of the European forest management and policy debate. Furthermore, a coherent and homogeneous monitoring system of natural disturbances is urgently needed in Europe, to better observe and respond to the ongoing changes in forest disturbance regimes.

This paper presents a new analysis of how global warming may affect the size of forest fires through its effects on air temperature, relative humidity, and wind speed. The effects of attack time on the size of the final burned area were also determined simultaneously in the statistical analysis. Two nonlinear functions determining the size of fires in the Prague-East District of the Czech Republic were estimated, based on a set of explanatory variables including air temperature, relative humidity, wind speed, and attack time. The functions were determined by multiple regression analysis combined with logarithmic transformations. The effects of climate change scenarios on future forest fires were calculated using the estimated fire-size function. The results show that if global warming leads to increased air temperature, reduced humidity, and stronger winds, we can expect larger fires. According to climate change scenarios, an upturn in the size of fires is predicted over this century. While we can control the fire by reducing the attack time, the results also show that if firefighters can reach a fire more quickly, the size of the fire will be reduced. If forest management methods, infrastructure, and fire brigade capacity are not adapted to the new climate, larger areas can be expected to be destroyed by fire.

This paper presents a new approach to identifying the climate variables that influence the size of the area burned by forest wildfires. Multiple linear regression was used in combination with nonlinear variable transformations to determine relevant nonlinear forest wildfire size functions. Data from the Prague-East District of the Czech Republic was used for model derivation. Individual burned forest area was hypothesized as a function of water vapor pressure, air temperature and wind speed. Wind speed was added to enhance predictions of the size of forest wildfires, and further improvements to the utility of prediction methods were added to the regression equation. The results show that if the air temperature increases, it may contain less water and the fuel will become drier. The size of the burned area then increases. If the relative humidity in the air increases and the wind speed decreases, the size of the burned area is reduced. Our model suggests that changes in the climate factors caused by ongoing climate change could cause significant changes in the size of wildfire in forests.

Long periods of drought and mild winters have significantly affected the forests of the Czech Republic in recent years. If this trend continues, forest stands will be weakened and dehydrated, which will increase the probability that forest fires will occur and spread. It is essential that fire managers prepare for this possibility. A main requirement for extinguishing large forest fires is the availability of water supply points. In this study, we determined if the Czech Republic has enough water to fight forest fires and whether these water supply points are distributed so that all forest stands will have enough water nearby to fight fires. We analysed forests, water supply points and forest roads in three study areas. One reservoir is sufficient to cover tens to hundreds of hectares of forest. We found that there are currently enough water supply points in the studied areas of the Czech Republic to extinguish forest fires. The results indicate that any shortage in water availability can be eliminated by using water supply points that are useable but that are not currently part of the database used by Fire Rescue Service of the Czech Republic. A thorough and regular update of the database of water supply points is therefore essential.

The Czech Republic has a fragmented terrain and a dense network of forest paths, making it an area where forest fires seldom cause catastrophic damage. As a result, forest fires causes in the Czech Republic have been considered by only a few authors. Foresters, scientists, and the public, however, are increasingly concerned about understanding and controlling forest fires in the country. Although the term "forest fire" is defined in the Regulation no. 2152/2003 of the European Parliament and Council and in a number of professional publications, the Czech literal translation is inaccurate and terminologically obsolete. Because basic terms relating to forest fires are lacking in the Czech language, we herein propose suitable Czech alternatives to the stable foreign terminology. In particular, we provide a new definition of "forest fire" and describe the main types of fires that occur in the Czech Republic. The numbers of forests fires varied between 444-1,398 per year in the period of 2006-2015, an average of 725 per year. The burned area is not commonly large, in average around 0.35 ha, and about 70% of all forest fires are smaller than 0.05 ha. The incidence of forest fires in the Czech Republic is not uniform, in some municipalities with extended powers there was no single forest fire, while in some municipalities there were more than ten forest fires. Estimated ratio between types of forest fires showed percentage superiority of surface forest fire (99.57%). Percentage of crown forest fires (0.04 %) and ground forest fires (0.39%) were almost negligible.

Abstract In the Czech Republic and Slovakia, the term “hollow tree fire“ was first used in a publication in 1956 without being well defined and was then uncritically used in other publications. The term refers to fires occurring in the rotted, inner trunks of trees. The main aim of the current study was to determine whether the term should be considered a useful category for the statistical analysis of forest fires. The nature and causes of fires from 2006–2015 were assessed by performing a detailed analysis of the Fire Rescue Service of the Czech Republic (FRS CR) database. The database included a total of 7,256 fires in the natural environment, but only 18 of these were hollow tree fires. Most hollow tree fires were initiated by human carelessness, and only three were initiated by lightning. Based on our critical consideration of fire attributes, hollow tree fires should not be considered a category of forest fire. The presence of rotten trees is, however, a serious problem because such trees represent long-lasting sources of fire in forest stands and because they complicate firefighting. The numbers of rotten trees in forests is increasing, and firefighters should be made aware of the complications of extinguishing fires involving rotten trees in forests.

Forest fires are complex physico-chemical phenomena. They involve burning, gas exchange, and heat transfer, and these processes change in space and time. An understanding of the spatial and temporal dynamics of these processes is necessary to prevent or extinguish forest fires. The Czech Republic attempts to prevent forest fires by educating the public about how forest fires occur, by requiring foresters and forest owners to report the burning of harvest residues, and by supporting the Air Fire Service. Forest owners can now monitor drought severity via internet sources and are able to estimate the risk of fire in their forests. In the period 2006-2015, most forest fires occurred between 14:00 and 17:00. The highest number of fires was recorded during weekends (+ ca 400), probably because of higher forest visitation by people on weekends; such visitation has been demonstrated to be positively correlated with forest fire occurrence. How firefighters respond to fires depends on the number of firefighters available, i.e. firefighters focus on attacking the fire when sufficient numbers of personnel are available but focus on defending people and property when numbers are insufficient. Determining whether the use of aviation technology or other approaches are appropriate for fighting a forest fire depends on the correct identification of the main parts of the fire.