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Sensitivities for the damaged trees network. "Wind damage intensity" shows the highest negative sensitivity (Min = −0.078) while "bark beetle damage intensity" shows the highest positive sensitivity (Max = 0.108).
Source publication
In mountain forests of Central Europe, storm and snow breakage as well as bark beetles are the prevailing major disturbances. The complex interrelatedness between climate, disturbance agents, and forest management increases the need for an integrative approach explicitly addressing the multiple interactions between environmental changes, forest man...
Context in source publication
Context 1
... predictions. In general, the sensitivity analysis of the bark beetle damage submodel shows only low to moderate sensitivities for all connected nodes. The highest sensitivity comes with the node "share of N. spruce", followed by "canopy closure". Figure 5 shows the sensitivities of the storm damage submodel (structure not shown here) to allow for an interpretation of the sensitivity effects in the damaged trees network. Figure 6 shows evidence of minimum and maximum sensitivity results for the overall model (damaged trees submodel) where the nodes "bark beetle damage intensity", "wind damage intensity", as well as "wind intensity" are the most influential on the overall results. The domain experts evaluated the plausibility of the BBN models using expert judgment on model response in various scenarios of input gradients within the case study ...
Citations
... Il serait enfin avisé de tester ou valider de façon statistique l'approche de Manion en mobilisant des méthodes modernes d'analyses de données comme les équations structurales (Haynes et al., 2022) ou les réseaux bayésiens (Radl et al., 2017). ...
Les changements globaux, combinant réchauffement climatique et invasions biologiques, menacent de plus en plus les écosystèmes forestiers. Différentes essences forestières ont été victimes de crises sanitaires ces dernières années en Europe. Les agents biotiques (champignons pathogènes, insectes ravageurs, bactéries, nématodes,…) peuvent jouer différents rôles dans ces crises, que ce soit en tant que facteurs prédisposants, déclenchants (primaires) ou aggravants (secondaires) selon le concept de Manion (1981). À la lumière des crises passées et actuelles impliquant des agents biotiques, nous passons en revue les outils et mesures de gestion disponibles afin de prévenir, éradiquer, enrayer ces crises sanitaires ou alors limiter leur impact. Messages clésLes changements climatiques menacent les écosystèmes forestiers.Les agents biotiques jouent souvent un rôle déclenchant ou aggravant dans les crises sanitaires.Des mesures de gestion peuvent être prises pour limiter l'impact des crises sinitaires.
... Various statistical methods, predictive models and expert systems have been applied to detect and prevent outbreaks of bark beetle (Netherer and Nopp-Mayr, 2005;Pasztor et al., 2014), including multi-criteria analysis methods, machine learning algorithms and remote sensing (Bright et al., 2020;Valdez Vasquez et al., 2020;Hollaus and Vreugdenhil, 2019;Radl et al., 2018;Seidl et al., 2016). Understanding the inter-dependencies of forest disturbance agents and involving different stakeholders in decision making considering spatial and temporal aspects of bark beetle outbreaks is challenging. ...
... Fuzzy-AHP and BBN are well known for their strengths in dealing with uncertainties and have proven to be robust in solving complex decision-planning problems (Malczewski and Rinner, 2015;Shao et al., 2020). Radl et al. (2018) studied storm and bark beetle agent disturbances in mountain forests at stand scale applying a BBN, including bark beetle damages as a sub-model, to predict the number of damaged trees. It has been evidenced that an understanding of Bayesian statistics is required for probabilistic analysis (Kokolakis, 2010), and deterministic analysis is useful in many applications. ...
... The fuzzy-AHP model is used to estimate the importance of the predisposition criteria for Ips typographus L. following the procedure described in Tahri et al. (2017). The structure of the probabilistic network of the BBN is set up comparatively to the fuzzy-AHP model following the recommendations of Radl et al. (2018). A geographical information system is used to map the estimated probability of bark beetle damages for both models based on national-scale input data for the Czech Republic. ...
The European spruce bark beetle ‘Ips typographus L.’ is the most serious disturbance agent for European forests. The complex interactions of many influencing factors need to be integrated into a model-based decision-support system to reduce the potential loss of forests. This paper compares two methodological approaches for spatially-explicit prediction of the predisposition for bark beetle infestations. The fuzzy analytic hierarchy process and the Bayesian belief networks were used in combination with a geographical information system to manage uncertainties. Using available data resources, the two approaches were evaluated to produce robust results for forest practitioners and to support measures to minimize the spread of bark beetles. The findings revealed that nearly 32% of the sites investigated in a case study were moderately-high or high risk categories. It is concluded that BBN is more efficient. Both methods can easily be used to analyze environmental problems involving complex interactions among various criteria.
... (e.g. Krejci et al., 2018;Netherer and Nopp-Mayr, 2005;Temperli et al., 2013), stand age, tree height, density, and growing stock (Díaz-Yáñez et al., 2017;Radl et al., 2017;Seidl et al., 2011b;Stadelmann et al., 2013). ...
... Trees are likely to reach large heights in dense stands, where competition for light is strong. A higher canopy cover thus contributes to higher disturbance susceptibility(Netherer and Nopp-Mayr, 2005;Radl et al., 2017). Our findings confirm this effect for spruce-dominated forests, but not in stands with a heterogeneous species composition (Figure 6.5). ...
... (e.g. Krejci et al., 2018;Netherer and Nopp-Mayr, 2005;Temperli et al., 2013), stand age, tree height, density, and growing stock (Díaz-Yáñez et al., 2017;Radl et al., 2017;Seidl et al., 2011b;Stadelmann et al., 2013). ...
... Trees are likely to reach large heights in dense stands, where competition for light is strong. A higher canopy cover thus contributes to higher disturbance susceptibility (Netherer and Nopp-Mayr, 2005;Radl et al., 2017). Our findings confirm this effect for spruce-dominated forests, but not in stands with a heterogeneous species composition (Fig. 5). ...
Mountain forests provide a wide range of ecosystem services, including carbon sequestration and protection from natural hazards. Forest cover in the European Alps has increased over the last century, but in recent years, these forests have experienced an increasing rate of natural disturbances by agents such as windthrow, bark beetle outbreaks, and forest fires. These disturbances pose a challenge for forest management, making it important to understand how site and stand characteristics, land use legacies and recent management influence disturbance probability. We combined a dataset of forest disturbances detected from space with in-situ forest management records, allowing us to differentiate between different types of disturbances for the Canton of Graubünden, Switzerland, in the years 2005–2018. The resulting dataset of over 28′000 attributed disturbance patches (corresponding to a disturbed forest area of ca. 23′600 ha) was combined with information on topography, forest structure, and historical forest cover. A machine-learning approach was used to investigate the non-linear and interacting relationships between potential drivers and disturbance occurrence. Natural disturbances (especially windthrow and bark beetle outbreaks) were most common at lower elevations, on shallow and south-facing slopes, and in even-aged, spruce-dominated stands with a closed canopy. Forests established in the 20th century were significantly more susceptible to natural disturbances than forests that were already present before 1880, which may be due to the uniform age and vertical structure of secondary forests, as well as legacy effects of former agricultural use. On the other hand, forest management more often took place in forests present before 1880. Management interventions (such as thinning) in turn increased the susceptibility to natural disturbances in the short term. This finding emphasizes the need to balance short-term increases in disturbance susceptibility with long-term benefits in forest resilience when planning management interventions in mountain forests. Our findings highlight the importance of considering multiple interactive drivers, including management and land-use history, for understanding forest disturbance regimes.
... additive effects, [53 ]), positive or negative [52 ]. Theoretical prediction could be even trickier when considering interactions with other climate-driven pressures like snowstorms and wild fires [54,55]. Emergent studies examining three or more drivers simultaneously show an even more complex picture. ...
Climate change is a multi-faceted phenomenon, including elevated CO2, warmer temperatures, more severe droughts and more frequent storms. All these components can affect forest pests directly, or indirectly through interactions with host trees and natural enemies.
Most of the responses of forest insect herbivores to climate change are expected to be positive, with shorter generation time, higher fecundity and survival, leading to increased range expansion and outbreaks.
Forest insect pest can also benefit from synergistic effects of several climate change pressures, such as hotter droughts or warmer storms.
However, lesser known negative effects are also likely, such as lethal effects of heat waves or thermal shocks, less palatable host tissues or more abundant parasitoids and predators.
The complex interplay between abiotic stressors, host trees, insect herbivores and their natural enemies makes it very difficult to predict overall consequences of climate change on forest health. This calls for the development of process-based models to simulate pest population dynamics under climate change scenarios.
... Forest management regimes were optimized while potential fire effects were simulated in this decision-support system that facilitated an examination of budgetary constraints. Radl et al. [8] describe the development of a Bayesian model designed to inform management planning processes that recognize natural disturbances (wind events and insect outbreaks). The model was applied in a case study to forests of southern Austria in an effort to analyze the trade-offs among management options of Norway spruce (Picea abies). ...
Climate and social changes place strong demands on forest managers. Forest managers need powerful approaches and tools, which could help them to be able to react to the rapidly changing conditions. However, the complexity of quantifying forest ecosystems services as well as the complexity of current decision theories, technologies and operation research methods, complicate the creation of one general tool. The continuous research and development in this area is an indispensable part of the success of adaptive management as well as the sharing of knowledge and information between research teams around the world. The Community of Practice of Forest Management Decision Support Systems provides a platform for broad discussion among scientists, researchers as well as forest professionals. This special issue provides papers which resulted from a conference session of the International Union of Forest Research Organizations’ (IUFRO) 125th Anniversary Congress in Freiburg, Germany in 2017. The joint sessions and other meetings (and resulting publications) are appropriate opportunities for knowledge sharing on these important methods and systems for protecting and managing forest ecosystems in the future.
In modelling human behavior during a fire, one has to deal with uncertainties regarding the psychological response due to limited or incomplete knowledge database. The purpose of this paper is to develop a new fuzzy Bayesian Network framework to model causal relationship of psychological response at the initial stage of fire events. Firstly, a new conceptual model namely the PRiF (Psychological Response in a Fire) is developed through the literature of human behaviour in fire evacuation modelling and expert opinion approach. Then, the expert elicitation using fuzzy linguistic concept was adapted in quantifying the PRiF model. Finally, an example of expert elicitation study is demonstrated to illustrate the practical application of the proposed methodology. Results show that the proposed methodology is not only able to capture the sequence of psychological reactions in line with the theory of human behavior in a fire but also can quantitatively measure the likelihood of circumstances of possible undesired scenario, and identify the most influential factors or prioritize the root causes of unsuccessful safe evacuation.
Context
Forest landscapes worldwide are shaped by abiotic drivers such as fire, windstorms, and drought, but also by biotic drivers like insect pests and pathogens. Although the effects of such drivers on forest dynamics have been studied extensively, knowledge of the interactions between insect pests and other drivers of change is still coarse and fragmented. Indeed, new invasive insect species and global change may lead to novel interactions and produce impacts on forest ecosystems never before experienced.
Objectives
We aimed to review the mechanisms underlying interactions between insect pest outbreaks and other forest disturbances, identify interactions emerging from current disturbance dynamics, and highlight the role of simulation models in exploring these interactions in a dynamic, mechanistic, and spatially explicit manner.
Methods
We reviewed the state of the science regarding interactions between insect pests and other forest disturbances, collecting a set of 216 scientific articles.
Results
Most studies focused on the interaction between insect outbreaks and fire, whereas interactions between insect pests and drought, forest management or forest diseases received much less attention. Although we identified some trends in how interactions were manifested, interactions were not more commonly found at particular spatial or temporal scales. Relatively few studies used simulation models to explore interactions between disturbances and very few studies explored multiple interactions.
Conclusions
Interactions between pests and other forest disturbances play critical roles in driving forest dynamics. The effects of these interactions are likely to increase in the face of continuing global change.
