BG3.9 | Natural Disturbances in Forest Ecosystems: managing increasing risk and addressing restoration needs

BG3.9

Natural Disturbances in Forest Ecosystems: managing increasing risk and addressing restoration needs

Natural disturbances are a primary driver of forest dynamics, thus shaping their composition and structure, and determining succession trajectories. Humans have always interacted with natural disturbances, and are in turn affected by the hazards posed by these events.
With the multitude of functions and services simultaneously and increasingly required from forest ecosystems, it is crucial to improve our understanding of the impact of natural disturbances on forests, also in light of the potential alterations introduced by different global change drivers, mostly due to anthropogenic activities.
Further attention is required to the many ways in which multiple disturbances (of biotic, abiotic and anthropogenic origin) interact with each other, thereby modifying the likelihood of occurrence and the effects of one another.
Despite an increasing awareness of the fundamental ecological role of natural disturbances, forest management still requires solid scientific input on how to increase the resistance and resilience of forests, and manage naturally disturbed landscapes to promote forest regeneration.
This complex situation calls for multi-scale, multi temporal, and multidisciplinary studies, taking advantage of field (in-situ) and remote sensing approaches, in order to capture the large heterogeneity and variability of the patterns and processes involved.
In the framework of the UN Decade on Ecosystem Restoration, preventing, halting and reversing forest ecosystems degradation due to lack of disturbances or altered disturbance regimes should become a focus of sustainable forest management.
In this session, we invite contributions from all fields in order to promote knowledge on disturbance ecology and management, aiming at developing methodologies and strategies to mitigate the impact of global change and its consequences on natural disturbances affecting forest ecosystems worldwide.

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Convener: Emanuele Lingua | Co-conveners: Matteo Garbarino, Raffaella Marzano, Tom Nagel, Alexandro B. Leverkus

Orals

| Thu, 27 Apr, 16:15–18:00 (CEST)

Room 2.17

Posters on site

| Attendance Thu, 27 Apr, 14:00–15:45 (CEST)

Hall A

Posters virtual

| Attendance Thu, 27 Apr, 14:00–15:45 (CEST)

vHall BG

Orals: Thu, 27 Apr | Room 2.17

The oral presentations are given in a hybrid format supported by a Zoom meeting featuring on-site and virtual presentations. The button to access the Zoom meeting appears just before the time block starts.

Chairpersons: Emanuele Lingua, Raffaella Marzano, Matteo Garbarino

16:15–16:20

5-minute convener introduction

16:20–16:30

EGU23-5182

ECS

Highlight

On-site presentation

Ecosystem services at risk from disturbances in European forests

Judit Lecina-Diaz, Cornelius Senf, Marc Grünig, and Rupert Seidl

In Europe, forest ecosystems are facing increasing disturbances such as wildfires, insect-outbreaks and windthrows, and the impacts of such events are likely to increase under ongoing climate change. Increasing disturbances can challenge forest resilience and vulnerability, resulting in higher risks of losing forest ecosystem services. However, quantifying risk across large spatial scales such as Europe is still a fundamental research challenge, since it requires understanding and evaluating the main elements of risk. In this study, we aim to assess the risk of losing forest ecosystem services due to the most common forest disturbances in Europe (wildfires, windthrows and insect-outbreaks – mainly spruce bark beetle). To do so, we mapped the risk components across European forests: exposed values, hazard magnitude, susceptibility and lack of adaptive capacity. Exposed values were quantified in terms of the ecosystem services provided by forests (i.e., timber volume, carbon stocks, soil erosion control, protection against gravitational hazards, and outdoor recreation), that could be lost if the disturbance occurs. The magnitude of the hazard and its probability distribution was quantified using integrative hazard indices (e.g., the Fire Weather Index for wildfires). Susceptibility was based on characteristics that modulate the immediate impacts of the hazard, such as tree height for windthrows or forest continuity for spruce bark beetle. Lack of adaptive capacity was assessed using historical post-disturbance canopy recovery of forests. We integrated and harmonized different indicators, datasets and maps for each risk component and disturbance. Then, we combined the risk components to obtain a risk map for each ecosystem service and disturbance considered, which allowed us to identify the areas with the highest risk. This study is the first ecosystem services’ risk assessment of European forests, which provides critical spatial information for these forests. Given that climate change could amplify forest disturbances, the results of this study could be used to anticipate and adapt to future conditions, as well as to guide efficient forest management.

How to cite: Lecina-Diaz, J., Senf, C., Grünig, M., and Seidl, R.: Ecosystem services at risk from disturbances in European forests, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5182, https://doi.org/10.5194/egusphere-egu23-5182, 2023.

16:30–16:40

EGU23-8928

ECS

On-site presentation

Cumulative Effects of Beaver Ponds and Forest Harvest on Streamwater Chemistry in Boreal Watersheds

Wai Ying Lam and Carl Mitchell

Canada’s boreal forests provide many important ecosystem services, including but not limited to biomass production, habitat provisioning, and soil and water protection. As forests are an important part of Canada’s economy and landscape, it is crucial that they are managed sustainably. In the province of Ontario, sustainable forest management is largely based on emulating natural disturbances. With respect to stream biogeochemistry, beaver ponds are one of the most common and significant disturbances against which to compare.

Thus, there is a need to further our understanding of how beaver ponds and forest management interact and modify the effects of one another. This study examined a suite of surface water chemistry variables, with a focus on the bioaccumulative neurotoxin methylmercury, in 28 headwater catchments across 3 years in northwestern Ontario. Some were undisturbed; some were impacted by active or abandoned beaver ponds; some were undergoing active harvest, while others were harvested previously; and some were impacted by active or abandoned beaver ponds and new or previous harvest.

Forest harvest impacts on organic carbon, suspended sediments, and mercury fell largely within the range of natural variation seen at undisturbed sites, except where significant soil and water disturbance from stream crossings occurred upstream. Pond impacts were highly variable, but more strongly related to catchment characteristics (such as mean slope and channel length) than to pond characteristics (such as shape and in-pond vegetation cover). Though downstream impacts were found to be greatest at a new pond in a catchment undergoing active harvest, pond and harvest impacts were not consistently additive in catchments where both occurred. Understanding the impacts of beaver ponds in conjunction with forest harvest is important for predicting the ultimate effectiveness of management decisions aimed at protecting terrestrial-aquatic ecosystems commonly affected by both disturbances.

How to cite: Lam, W. Y. and Mitchell, C.: Cumulative Effects of Beaver Ponds and Forest Harvest on Streamwater Chemistry in Boreal Watersheds , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8928, https://doi.org/10.5194/egusphere-egu23-8928, 2023.

16:40–16:50

EGU23-8478

On-site presentation

Large-scale remote sensing exploration of the resilience of Iberian holm oak woodlands to extreme droughts

Mariano Moreno de las Heras, Esther Bochet, Sergio Vicente-Serrano, Tiscar Espigares, María José Molina, Vicente Monleón, José Manuel Nicolau, Jaume Tormo, and Patricio García-Fayos

The organization and function of forest ecosystems is changing at an unprecedent rate under the influence of external drivers, such as climate change and human uses. In this context of change, the increasing frequency, intensity and duration of droughts that affect the Mediterranean basin urges to evaluate forest vulnerability to drought and their effects for the long-term stability of these ecosystems. In this study, we explore the responses and factors that control the resilience of holm oak (Quercus ilex) woodlands to recent extreme droughts during 2000-2019, using a remote sensing approach over a broad scale climate aridity gradient that extends from sub-humid to semi-arid climate conditions over 100,000 km² in eastern Spain. Overall, our results indicated that climate aridity and forest structure largely control the resistance, recovery and resilience of the studied holm oak woodlands to drought, which are also affected by drought intensity and both pre- and post-drought hydric conditions. We found that Q. ilex woodlands located in the dry edge of the explored climate aridity gradient showed a high sensitivity to extreme drought. Their resistance, assessed as the capacity of the woodlands to maintain primary production during drought, was low. They also showed a poor resilience, characterized by a low capacity to fully recover their pre-drought production levels. Contrarily, holm oak woodlands in sub-humid areas of the study region, where wetter climate conditions may alleviate water stress during dry periods, showed a high resistance and resilience to the effects of droughts. Drought vulnerability was particularly high for dense holm oak stands developed under semi-arid climate conditions, where strong competition for scarce water resources largely increased the negative effects of extreme drought on landscape-level ecosystem production. We also discuss the implications of these results for adaptive management of holm oak forests in the present context of climate change.

How to cite: Moreno de las Heras, M., Bochet, E., Vicente-Serrano, S., Espigares, T., Molina, M. J., Monleón, V., Nicolau, J. M., Tormo, J., and García-Fayos, P.: Large-scale remote sensing exploration of the resilience of Iberian holm oak woodlands to extreme droughts, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8478, https://doi.org/10.5194/egusphere-egu23-8478, 2023.

16:50–17:00

EGU23-3682

ECS

On-site presentation

Climate-smart forest management may decrease vulnerability of forest carbon to disturbances

Natalie Piazza, Edoardo Nevola, and Giorgio Vacchiano

Natural disturbances like windthrows or forest fires have an effect on the provision of ecosystem services like timber production, protection from natural hazards or carbon sequestration. After a disturbance, forests release large amounts of carbon and therefore change their status from carbon sinks to carbon source. However, forest management may improve the forest capacity to absorb carbon by decreasing the vulnerability to disturbances. In this study we used simulation tools ForestGALES (windthrow) and FlamMap (forest fire) to model the vulnerability to the two disturbances. We analysed forest stands prone to windthrow (in the Carnic Alps) and forest fire (in the Apennines) and proposed forest management in the most vulnerable forest stands, increasing their resistance to the respective disturbance. We simulated the future carbon stock and sink under two scenarios: (1) business-as-usual management, and (2) forest improved using climate-smart forest management to decrease the vulnerability to disturbances. Forest under business-as-usual management led to a decrease in total carbon. Using climate-smart management compared to business-as-usual resulted to an increase of carbon stocks (with additional increase in case of no disturbance). We showed that using disturbance simulation tools may help in decision making process to analyse the most vulnerable forest stands. In combination with simulations of future scenarios of carbon we may be able to direct the climate-smart forestry.

How to cite: Piazza, N., Nevola, E., and Vacchiano, G.: Climate-smart forest management may decrease vulnerability of forest carbon to disturbances, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3682, https://doi.org/10.5194/egusphere-egu23-3682, 2023.

17:00–17:10

EGU23-13264

ECS

On-site presentation

Novel indices for analysis of protection against snow avalanches in wind-disturbed forest

Tommaso Baggio, Natalie Piazza, Alexander Bast, Peter Bebi, and Vincenzo D'Agostino

Windthrows are natural disturbances affecting the structure of forests. Such events are predicted to increase in magnitude and frequency due to climate change. The altered forest structure influences forests’ protection capacity against the release of snow avalanches. Previous studies investigated windthrown forest characteristics and their recovery time in study areas smaller than 10 ha, not accounting for larger spatial scales. In this study, we developed a new method for the spatial assessment and monitoring of forests affected by large-scale windstorms to evaluate the protection against the release of snow avalanches. We propose the use of two indices: (1) stored volume height, assessing the uniformity of the biomass on the ground, and (2) adapted tree parameters, evaluating the characteristics of the standing trees. We implemented the algorithm in the R environment and published the scripts on https://github.com/TommBagg/Wind-disturbed_forest_analysis.

The developed indices were applied in two unmanaged windthrow areas periodically surveyed with photogrammetric techniques (deriving dense point clouds) to investigate the long-term changes in protective effects (Disentis, Switzerland) and the short-term influence of snow cover (Franza, Italy). The first area was affected by the storm Vivian in 1990 and four surveys have been performed (1991, 2001, 2009 and 2019), while the storm Vaia hit the Franza area in 2018 and three surveyed were performed (October 2019, October 2020 and December 2020). Analyzing the Disentis area, over 29 years, the minimum level of protective capacity was observed ten years after the storm event. As forest recovery proceeded, forest protective capacity increased again and natural regeneration has progressively provided an anchoring effect against the release of snow avalanches, 29 years after the windthrow event. However, a careful evaluation of the gaps between growing trees (outcome of the adopted tree parameters index) should be performed, as deadwood in these gaps decays, facilitating the potential avalanche formation. The stored volume height was further used to evaluate the forest protection in relation to the snow cover height in the Franza (IT) area, evaluating the necessary snow amount to smooth the rough surface created by the biomass on the ground. This study provided new insights into the long-term protective efficiency of windthrow forests, introducing two new indices to spatially assess and monitor their development over time.

How to cite: Baggio, T., Piazza, N., Bast, A., Bebi, P., and D'Agostino, V.: Novel indices for analysis of protection against snow avalanches in wind-disturbed forest, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13264, https://doi.org/10.5194/egusphere-egu23-13264, 2023.

17:10–17:20

EGU23-13775

ECS

On-site presentation

Canopy gap creation and closure in temperate mountain forests identified from multi-temporal lidar data

Kirsten Krüger, Dirk Pflugmacher, Cornelius Senf, Tommaso Jucker, and Rupert Seidl

Canopy gaps are the fingerprint of forest disturbances, with forest disturbances being the driving force of forest dynamics. Forest gaps can substantially vary in size, from small groups of trees to several hundreds to thousands of hectares being disturbed by windthrow, outbreaks of tree-killing insects or fire. Gap creation is a complex process, because individual disturbance agents can interact, eventually forming larger gaps from linked disturbance events. We still know little about the emergence of gaps: I.e., do small gaps beget large gaps by continuously growing larger, or are small gaps staying small, and large gaps are created large? Furthermore, in order to understand the effect of gaps on forest dynamics, it is equally important to consider gap closure, as the interplay between gap creation and closure determines how persistent gaps are. To address these issues, we here investigated natural patterns of canopy gap creation and closure in an unmanaged temperate mountain forest ecosystem in the Berchtesgaden National Park. Three repeated lidar acquisitions from 2009, 2017 and 2021, covering 3543 ha of closed forest enabled the analysis of gap creation, pervasiveness and closure rates. We delineated gaps from lidar derived Canopy Height Models by thresholding vegetation < 5m and applying a minimum gap size of 400 m² (i.e., approximately the size of one large canopy tree). The identification of gap creation, expansion and closure was done by subtracting each year’s individual gap layers. New and expanding gaps were classified by the presence of gaps in the same geographical location in the previous time step. Crown plasticity leading to lateral closure of gaps vs. ingrowth of regenerating trees are differentiated by the distance to the forest edge and a maximum vertical vegetation height gain during the respective observation period. First results indicate a higher annual gap closure rate (0.66% per year) than annual gap creation rate (0.38% per year), reducing the total gap area across the study area from 22.8% in 2009 to 19.1% in 2021. With increasing elevation, both gap creation and closure increase. Gap expansion is the dominant process of gap creation, underlining the spatially contagious nature of the dominant disturbance agents in the area, such as bark beetles and windthrow. Wind creates edges, which are again more susceptible to wind and provide abundant breeding material for bark beetles that can infest neighboring stands, again creating edges susceptible to wind. Regeneration is the dominating process of gap closure, while lateral crown expansion plays a crucial role mainly in broadleaved forests dominated by European beech. Smaller gaps close disproportionally faster than larger gaps and mixed forests close gaps faster than pure forests, likely due to niche complementarity. Overall, our study presents the first landscape-scale assessment of canopy gap creation and closure in temperate mountain forests and adds to our understanding of forest dynamics.

How to cite: Krüger, K., Pflugmacher, D., Senf, C., Jucker, T., and Seidl, R.: Canopy gap creation and closure in temperate mountain forests identified from multi-temporal lidar data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13775, https://doi.org/10.5194/egusphere-egu23-13775, 2023.

17:20–17:30

EGU23-11707

On-site presentation

Modeling post-fire regeneration patterns under different restoration scenarios to improve forest recovery in degraded ecosystems

Giulia Mantero, Nicolò Anselmetto, Donato Morresi, Fabio Meloni, Paola Bolzon, Emanuele Lingua, Matteo Garbarino, and Raffaella Marzano

Applied nucleation (AN) is a nature-based solution alternative to traditional regular plantations. It is a cost-effective technique that integrates artificial seedlings and natural regeneration dynamics to enhance forest recovery, mimicking successional processes. Given the current shift of disturbance regimes caused by global change, this technique will likely be a valuable active restoration approach for many forest ecosystems affected by extreme disturbance events. Indeed, AN is suitable for ecological restoration after stand-replacing events, improving seed availability and microsite conditions supporting natural regeneration. AN has been mostly applied in tropical forests, but its use in Mediterranean forests should be increasingly considered since a higher occurrence of large and severe fires has been observed over the last decades and further increases are expected in the future. These changes are raising concerns about regeneration recruitment, particularly for obligate seeders in mountain ecosystems. In these ecosystems, it is crucial to reconsider current post-fire policies to identify strategies that promote and maintain the ecosystem services of degraded forests, particularly when natural regeneration is ineffective. The main aim of this study was to define the best methodology for implementing AN in a mountain area affected by a large stand-replacing fire that occurred in 2005 in the Aosta Valley Region (North-Western Italy). After the fire salvage logging was performed, increasing ecosystem degradation, and, 16 years later, natural regeneration is still scarce and struggling to settle. Hotspots for AN were identified based on post-fire natural regeneration response to a series of site characteristics, such as topography, fire severity, and distance from seed trees. We assessed the drivers of post-fire regeneration through a machine learning correlative model (Bayesian Regression Tree, BART). The probability of regeneration presence across the landscape was then predicted under the current situation and a set of AN scenarios. Starting from the current scenario, we reclassified the prediction raster into three levels, according to the probability of presence and uncertainty. Polygons with low uncertainty and probability (< 0.3) were included in level one and considered hotspots for AN. From these predictions, it was possible to assess the most efficient active management scenario to speed up the regeneration process. Our results showed that AN could be a promising post-fire management technique for promoting natural regeneration while limiting anthropic interventions and their related economic and ecological costs.

How to cite: Mantero, G., Anselmetto, N., Morresi, D., Meloni, F., Bolzon, P., Lingua, E., Garbarino, M., and Marzano, R.: Modeling post-fire regeneration patterns under different restoration scenarios to improve forest recovery in degraded ecosystems, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11707, https://doi.org/10.5194/egusphere-egu23-11707, 2023.

17:30–17:40

EGU23-16997

On-site presentation

Mosaic landscape restoration after wildfire under Mediterranean-continental conditions

José Manuel Nicolau Ibarra and Ramón Reiné

Wildfire is a natural disturbance in the Iberian Range, often caused by lightning. After the 7,600 ha fire in the Cuencas Mineras de Teruel region in 2009, a restoration project is being carried out on 1,234 ha with the aim of developing a forest adapted to challenges as a) new climate scenario; b) future fires; c) wild ungulate expansion/livestock management. Four ecosystem services have been prioritized: water supply, carbon storage, livestock feeding, and biodiversity.

Forest recovery has been promoted by means of plantations as well as spontaneous revegetation (26% and 11,5% respectively of the pre-fire forest surface). Plantation has been made in scattered stands in order to create fire discontinuity. Trees density has been lowered (750-1.100 trees/ha) to reduce fuel in the forest and increase water availability per tree. Resprouting and seeding species have been introduced. Pinus halepensis has been planted above 1,000 m of altitude because conditions are getting drier and warmer. Since 2014 71,75 ha have been planted with a survival rate of around 63,5%. The least successful species has been Pinus sylvestris (50% on average) with the lowest records in sunny exposures and convex landforms due to the new climatic scenario. The sustainable stocking density has been estimated at 700 ewes to promote livestock activity. In order to enhance the sheep flock activity a livestock pen has been built that allows the grazing season to be extended over time. We assume that in planted stands, rainwater will be consumed by the vegetation (evapotranspiration: green water). In non-planted areas, livestock activity is encouraged, thus acting as firebreaks and as producers of blue water, since part of the rainwater will recharge aquifers and watercourses.

Biodiversity results favored by spontaneous revegetation as well as by the protection of the Natura 2000 habitat 6210 “Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia)”, which has not been planted. In practice, a mosaic landscape has been constructed.

The water supply (blue/green water ratio) has been estimated by applying Zhang's hydrological model. Barandica and Berzosa model was used for carbon storage estimation. Four scenarios have been considered: a) traditional land uses before rural depopulation (the year 1956); b) pre-fire landscape (the year 2009); c) post-fire landscape (the year 2012); d) restored forest (the year 2050). Results show an increase of about 4,5% in water supply and a decrease of about 40% in carbon storage when comparing the pre-fire scenario with the restored forest. An integrative approach including the management of water, carbon, livestock, and biodiversity is necessary in order to develop mosaic landscapes resilient to the main disturbances in the Mediterranean-continental environments.

How to cite: Nicolau Ibarra, J. M. and Reiné, R.: Mosaic landscape restoration after wildfire under Mediterranean-continental conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16997, https://doi.org/10.5194/egusphere-egu23-16997, 2023.

17:40–17:50

EGU23-17298

On-site presentation

Monitoring European beech leaf phenology along its southern extreme of range distribution in different years in relation to site characteristics and silvicultural treatments

(withdrawn)

Maria Cristina Monteverdi, Roberta Proietti, Serena Antonucci, Marco Di Carlo, Sebastian Marzini, Vittorio Garfì, and Ugo Chiavetta

17:50–18:00

EGU23-15197

Virtual presentation

Ditch Erosion Processes triggered through Strong Precipitation Events: Implications for Forest Ecosystem Stability and Water Resources Protection

Roland Koeck, Franz Suppan, and Eduard Hochbichler

Within the forested karstic alpine water protection zones of various water suppliers in Austria like e.g. those of the Cities of Vienna and Waidhofen/Ybbs, strong precipitation events have triggered erosion processes in ditch sites, causing forest decline and turbidity in the related karstic aquifers. Both processes are intended to be mitigated or avoided, as forest cover and water supply are negatively influenced by these natural disturbances. As response strategy an outstanding precipitation event from the year 2013 on Mount Rax was analyzed both on the level of (A) the meteorological characteristics of this event and (B) it’s impacts on ditch sites and forest cover within the part of the water protection zone affected by this rainfall event (WPZ).

The meteorological characteristics of the event from 9^th of August 2013 define it as outstanding strong precipitation event, yielding 79,2 mm of rainfall within the first 2 hours and 119,2 mm within the whole event (10 hours). It was a thunderstorm event including hail, which became visible by soil temperature analysis. The inclusion of hail lowered the temperature of the water moving in and on the forest soils, by the way increasing its erosive potential through boosting its drag force for any given substances, in our context soil materials. The data stem from high temporal resolution hydro-meteorological stations (10 minutes measurement interval) within the WPZ. The precipitation event caused major impacts on ditch sites, like deep v-notch erosion or erosion of the upper soil substances and forest roads.

Therefore, the ditch sites within the WPZ were analyzed both through interpretation of aerial orthophotos and a field mapping survey leading to the GIS-based processing of the yielded data. It was possible to show that especially ditch sites beneath rock areas showed strong erosion dynamics affecting both forest vegetation cover and soil substances. Deep v-notch erosion occurred in such ditch types. Also totally new ditch sites were created through the analyzed event. In the course of the mapping survey, the soil type, vegetation cover and percentage of the site affected through erosion processes were analyzed.

The only chance to mitigate the impacts of the natural disturbance category “outstanding strong precipitation events” is a stable, vital and dense vegetation cover on ditch sites, including both ground vegetation and tree cover. Especially stable tree species like Sycamore Maple (Acer pseudoplatanus) or European larch (Larix decidua) can facilitate the stability of vegetation cover on ditch sites. The mitigation of the erosion processes has positive effects on forest cover, and above all, on water supply systems, as increased turbidity is one of the main causes for water quality issues in karstic alpine watersheds. Because of this fact it is necessary to avoid processes which damage the natural regeneration dynamics of forest ecosystems, like e.g. browsing damages on tree species. Strategical efforts of forest management have to focus on the stabilization of vegetation cover on such ditch sites. Those are supported through the Forest Hydrotope Model (a forest site model) data base which was elaborated for the WPZ.

How to cite: Koeck, R., Suppan, F., and Hochbichler, E.: Ditch Erosion Processes triggered through Strong Precipitation Events: Implications for Forest Ecosystem Stability and Water Resources Protection, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15197, https://doi.org/10.5194/egusphere-egu23-15197, 2023.

Posters on site: Thu, 27 Apr, 14:00–15:45 | Hall A

The posters scheduled for on-site presentation are only visible in the poster hall in Vienna. If authors uploaded their presentation files, these files are linked from the abstracts below, but only on the day of the poster session.

Chairpersons: Raffaella Marzano, Emanuele Lingua, Matteo Garbarino

A.226

EGU23-15667

ECS

Highlight

On-site presentation

Microsite amelioration by post-fire deadwood in a Pinus nigra planted forest in central Italy

Flavio Taccaliti, Davide Marangon, Alessandro Vitali, Carlo Urbinati, Raffaella Marzano, and Emanuele Lingua

The widespread role of fire in shaping ecosystem composition and distribution, as well as its evolutionary importance, are nowadays fully recognized by scientists. In contemporary ecosystems, forest fires can induce different kinds of effects, depending on species characteristics, with the presence of fire-related traits often allowing full ecoystems recovery also after stand replacing or high severity events.
By modifying growing space conditions (e.g. exposed bare soil, reduced competition), forest fires may trigger ecological processes such as forest regeneration. In the absence of specific fire adaptations, biological legacies persisting after the event have been proven crucial to drive regeneration dynamics. Indeed, deadwood can create safe sites and favourable microsite conditions for seedling establishment and survival. Despite the potential increase in coarse dead fuel load resulting from post-disturbance deadwood, its removal (e.g. through salvage logging activities) can cause long lasting negative effects on the ecosystems and the services they provide, often delaying or altering forest recovery.
Studies are needed to assess the importance of facilitation mechanisms in different post-fire conditions, in order to provide suitable information on deadwood management and Assisted Natural Regeneration approaches to forest planners and managers.
In a xeric Pinus nigra planted forest in central Italy (Marche Region) affected by a large crown fire in 2017, soil temperature and moisture were measured in the topmost 5 cm of soil at various distances (n = 5) from downed logs (n = 14). Values were recorded in nine time steps during the summer of 2022.
A significative positive effect of downed logs on microsite conditions (lower summer temperature, higher soil moisture) was observed. Based on these first results, a long-term monitoring project has been set up to evaluate if regeneration has actually a better performance in the identified microsites. An extensive natural regeneration sampling was performed in the burnt area, and artificial regeneration, both from seeds and trasplanted seedlings, was placed at different positions around the deadwood, trying to mimic the patterns of natural regeneration.
The preliminary otuputs of this study will be integrated with other case studies and further field sampling campaigns, but they suggest that post-fire deadwood can facilitate natural regeneration and should not be completely removed from burnt areas.

How to cite: Taccaliti, F., Marangon, D., Vitali, A., Urbinati, C., Marzano, R., and Lingua, E.: Microsite amelioration by post-fire deadwood in a Pinus nigra planted forest in central Italy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15667, https://doi.org/10.5194/egusphere-egu23-15667, 2023.

A.227

EGU23-11425

ECS

On-site presentation

Forest fires simulation in the Alpine region. New data and innovative approaches needed

Luca Mauri, Flavio Taccaliti, and Emanuele Lingua

Among the predominant natural disturbances affecting Mediterranean regions, nowadays forest fires frequently occur in Central and Northern Europe, potentially leading to several issues in ecological, geomorphological, economic and social terms. In this regard, local authorities are becoming gradually confident with their management even where forest fires were historically scarce. In this context, semi-empirical models are particularly useful in estimating fire behaviour, in order to predict key factors related with wildfires risk (e.g., flames length, fire type, rate of spread). At the same time, accurate estimation of models inputs actually represents the principal limitation to outputs reliability, mainly due to the difficulty in retrieving specific data like canopy fuel characteristics or fire behaviour fuel models. In light with the above, there is a growing need to find new methods able to infer such simulation variables, for example starting from remote sensing data acquisition and elaboration, as well as by adapting already existing equations and workflows to European specific contexts. The project RETURN aims therefore to enhance the spatial mapping of fire simulators inputs layers within the Alpine region by coupling an extensive field data collection with high-resolution Light Detection and Ranging (LiDAR) and Unmanned Aerial Vehicle (UAV)-based data collection. The results of the Project could be useful in increasing the amount of information available for local administrations of the Alpine region, aiming to ease the application of fire behavior simulators to manage such a natural disturbance increasingly frequent in this mountain area.

How to cite: Mauri, L., Taccaliti, F., and Lingua, E.: Forest fires simulation in the Alpine region. New data and innovative approaches needed, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11425, https://doi.org/10.5194/egusphere-egu23-11425, 2023.

A.228

EGU23-11708

ECS

On-site presentation

Assessment of the impact of the Italian National Forest Strategy on carbon sequestration in the Lazio region up to 2030

Ekaterina Tarasova, Maria Vincenza Chiriacò, and Lucia Perugini

The sustainable policies and practices such as agricultural, forestry and land management are crucial for ensuring the long-term provision of ecosystem services. According to the European Green Deal strategy, at least 3 billion more trees should be planted in the European Union by 2030. In support of this target, the Italian National Forest Strategy proposes actions aimed at reforestation, afforestation and agroforestry. Enhancing forest density and cover enhances the capacity to remove CO₂ and store it as organic carbon in the global terrestrial biosphere. Spatial decision support tools can support policy makers in addressing these challenges and relevant assessment of land-based mitigation options to reduce emissions in the land sector. Despite the specific goal set in the European Green Deal strategy, there is still no clear understanding of which territory in Italy will be involved in the planned actions. Therefore, there is a need to build suitability maps to determine the future change of the land cover in connection with the European strategies and planned actions up to 2030. This study suggests not only possible future land cover maps for the Lazio region, compiled in accordance with the land use policy, but also an assessment of the planned carbon sequestration based on the proposed maps.

How to cite: Tarasova, E., Chiriacò, M. V., and Perugini, L.: Assessment of the impact of the Italian National Forest Strategy on carbon sequestration in the Lazio region up to 2030, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11708, https://doi.org/10.5194/egusphere-egu23-11708, 2023.

A.229

EGU23-14563

ECS

Highlight

On-site presentation

Reconstructing forest dynamics in the European Alps through a high-dimensional analysis based on Landsat time series

Donato Morresi, Hyeyoung Maeng, Raffaella Marzano, Emanuele Lingua, Renzo Motta, and Matteo Garbarino

Natural disturbances are increasingly threatening forest ecosystems due to climate change globally. In
Europe, disturbance regimes have intensified over the last decades, leading to increased size, frequency
and severity of disturbance events. Satellite remote sensing data acquired over the past decades are crucial
for assessing changes in disturbance regimes as they provide wall-to-wall spatial information from the
landscape to the global scale. In particular, Landsat imagery has been continuously acquired since 1984,
and it offers an unprecedented opportunity for mapping land cover changes thanks to its spatial and
spectral consistency. Following the opening of the USGS Landsat archive, dense time series have been
exploited through automated algorithms for targeting forest dynamics. Currently, the most widely used
algorithms aim to detect abrupt and gradual changes by performing a temporal segmentation of Landsat
time series at the pixel level. The sensitivity of automated algorithms has been enhanced by including
multiple spectral and spatial information in the time series though their combined usage is still limited.
Here, we present an automated algorithm for detecting forest dynamics named High-dimensional detection
of Land Dynamics (HILANDYN), which exploits the temporal, spatial and spectral dimensions of inter-annual
Landsat time series. We tested HILANDYN to map forest disturbances that occurred during the last four
decades in the European Alps. HILANDYN builds upon a statistical procedure for detecting changepoints in
high-dimensional time series through a bottom-up segmentation procedure. Our results showed that the
algorithm is sensitive toward a wide range of disturbance severities and can detect stand-replacing events,
e.g. windthrows and wildfires, and non-stand-replacing ones, e.g. insect outbreaks and drought-induced
dieback. Moreover, we were able to map disturbances occurring in consecutive years, such as windthrows
followed by salvage logging. We obtained the best results in terms of accuracy metrics using a combination
of original bands and indices that included the heterogeneous spectral information provided by the
multispectral sensors of the Landsat missions. In particular, we achieved an F1 score equal to 83% for the
disturbed class, corresponding to a user’s accuracy of 84,3% and a producer’s accuracy of 82%. Accurate
disturbance maps of the European Alps will enable a thorough analysis of the shifts in the disturbance
regimes over the last four decades, alongside the assessment of forest recovery patterns under different
management practices and environmental conditions.

How to cite: Morresi, D., Maeng, H., Marzano, R., Lingua, E., Motta, R., and Garbarino, M.: Reconstructing forest dynamics in the European Alps through a high-dimensional analysis based on Landsat time series, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14563, https://doi.org/10.5194/egusphere-egu23-14563, 2023.

A.230

EGU23-9351

ECS

On-site presentation

Vulnerability assessment to wind damage in a protective forest stand in the Alps.

Maximiliano Costa, Barry Gardiner, Tommaso Locatelli, Tommaso Baggio, Niccolò Marchi, and Emanuele Lingua

The risk of wind damage to European forests is expected to increase due to the changed climate. Therefore, research efforts in forestry have been focussing on the development of analytical and modelling tools to improve the prediction of forests' susceptibility to wind damage, and ultimately to support forest management decisions in increasing wind resistance in forest stands. Recent catastrophic wind damage to European forests has shown that wind damage risk applies also to montane forests. Some of them are of particular importance for the various ecosystem services they provide, including protection from gravitational hazards and defence against soil erosion. At present, the available forest wind risk models have been tested and used mainly on production or planted forests in different countries, but never in the complexity of mountainous terrains. The aim of this study is to introduce a methodology for the validation of a new parametrization of ForestGALES wind risk model for the alpine environment. The parameterisation was developed through field tests (e.g., pulling tests on trees) and validated based on the observed wind damage caused by the storm Vaia, which occurred in northern Italy in October 2018, and the pre-disturbance forest characteristics. The use of this parameterisation can allow the construction of wind vulnerability maps starting from LiDAR data. Mapping vulnerability to natural disturbances, in this case, wind, is an essential tool for forest planning and management. The frequency of natural disturbances is expected to increase, as is their severity and forest management needs to target interventions to obtain more resistant and resilient forest stands. Management should aim to apply strategies to prevent future damage in a way that ensures continued protective effectiveness, guaranteeing the preservation of local communities and infrastructures.

How to cite: Costa, M., Gardiner, B., Locatelli, T., Baggio, T., Marchi, N., and Lingua, E.: Vulnerability assessment to wind damage in a protective forest stand in the Alps., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9351, https://doi.org/10.5194/egusphere-egu23-9351, 2023.

A.232

EGU23-12981

ECS

On-site presentation

Overall analysis of protective effects of forest on shallow landslides triggered by storm Vaia in Agordino (Italy)

Lorenzo Faes, Andrea Rizzi, Maximiliano Costa, Paul Richter, and Emanuele Lingua

Shallow landslides are one of the most frequent gravitative natural hazards in the Alpine region that could affect human infrastructures. Forests can play a direct protective function, preventing the triggering of such events thanks to the role they play in water regulation and mechanical effects, in particular with root reinforcement. Few studies, however, report empirical assessments, based on after-events shallow landslides inventory, of the protective effects given by the presence of the forest on this natural hazard. With this study, an attempt was made to assess the possible influence of the presence of the forest on the topographic triggering conditions and the magnitude of the landslides respect to those triggered in open lands. A comparison was then developed between the structural characteristics of forest stands, in which landslides were recorded, and the reference parameters of the protection forests guidelines. In addition, it has been evaluated how root reinforcement can have an influence at a local scale on the location of shallow landslide triggering. Finally, a subsample of the forest landslides was selected for field surveys, in order to analyze the influence of stand structure on the magnitude of landslides. The study area corresponds to the territory of upper Agordino valley (405 km²), in the Veneto Region (Italy), which was severely affected by storm Vaia in October 2018 that caused widely the trigger of numerous shallow landslides and large windthrows. Through the analysis of the orthophotos pre and post-event and the Dem of Difference of DTMs, overall 469 (116 triggered in the forest) shallow landslides were identified with median values of area of 177 m² and volume of 163 m³. In terms of density, forest landslides are less frequent than those in open lands and are triggered on slopes with higher inclination. Forest stands where landslides were recorded show median values of coverage of 60%, gap area of 551 m², gap length of 18 m, and gap width of 16 m. It turned out that comparing to the silvicultural guidelines on the management of protection forests, the most important parameter appears to be the gap length. Such gaps represent the weakest zone in terms of root reinforcement where the landslides can be triggered more easily. This has been confirmed by the application, at the plot scale, of the SOSlope model (Cohen and Schwarz, 2017) which results that most of the landslide scarps (42 out of 53) were located in the zones with the lowest lateral root reinforcement. A multivariate analysis carried out on data collected in the field on a subsample of 20 forest landslides highlights that landslides with higher volume and area were recorded mostly in young forests with high density. A stand with a good amount of large trees and an uneven-aged structure seems to be the most effective in these terms. These results emphasize the protective effects of forests against shallow landslides and suggest the need for their optimal silviculture management, taking also into account the increasing susceptibility to other natural disturbances which could compromise the protective function.

How to cite: Faes, L., Rizzi, A., Costa, M., Richter, P., and Lingua, E.: Overall analysis of protective effects of forest on shallow landslides triggered by storm Vaia in Agordino (Italy), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12981, https://doi.org/10.5194/egusphere-egu23-12981, 2023.

A.233

EGU23-13435

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On-site presentation

Increasing the value of windstorm damaged forest: combining restoration practices and agroforestry

Davide Marangon, Emanuele Lingua, Claudio Betetto, Luca Cadez, and Giorgio Alberti

After stand-replacing windstorm salvage logging is the most common practice for recovering economic losses in managed forests and for reducing the risk of subsequent disturbances (e.g. bark beetle outbreaks). To restore forest cover timely after these interventions is therefore necessary, in order to limit the reduction of forest ecosystem services (ES) provision. In the first years following the disturbance and subsequent interventions, there is a need to monitor natural regeneration dynamics in damaged areas, in order to implement active restoration activities if necessary. In this study, we analyze the natural regeneration dynamics in 148 areas damaged by storm Vaia (2018) and salvage logged with different techniques in Northeast of Italy. Results show that regeneration species composition is driven mainly by previous stand composition, with some exceptions depending on seed dispersal strategy. Distance from the edge significantly influences the regeneration occurrence in large gaps and affects the browsing damage percentage, together with deadwood presence. Moreover, site factors, disturbance legacies, and logging methods reveal to be key points to consider in the post-disturbance management strategies definition. To reduce economic losses and exploit the windthrown areas in the short-term, it is possible to integrate reforestation with agroforestry practices (e.g. berries and honey production). This is the framework of the LIFE VAIA project, which aims to integrate innovative local agroforestry practices with artificial regeneration to restore forest cover, increasing the value of forest ecosystems and the ecological and socio-economical resilience of damaged forest ecosystems under future climate changes.

How to cite: Marangon, D., Lingua, E., Betetto, C., Cadez, L., and Alberti, G.: Increasing the value of windstorm damaged forest: combining restoration practices and agroforestry, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13435, https://doi.org/10.5194/egusphere-egu23-13435, 2023.

A.234

EGU23-10878

ECS

On-site presentation

Assessing net primary productivity in tree nursery points of North Korea using biogeochemistry model

Cholho Song, Stephan A. Pietsch, Jiwon Kim, Hyun-Ah Choi, and Woo-Kyun Lee

Forests of North Korea are important ecological corridors of the east side of the Mid-Latitude Ecotone (MLE) connecting to South Korea, but they have been degraded in the 1990s-2000s. Although recent increasing trends in forest areas were reported by quantitative land cover classification using remote sensing data, the quality of the forest ecosystem such as net primary productivity (NPP) was not evaluated appropriately because of limited field surveys, forest management, and reforestation activities under the complex political situation in North Korea. Therefore, process-based modeling can contribute to understanding the qualitative changes in the North Korean forest. This study selected 14 tree nursery points close to deforestation, considering land cover maps from the Korean Ministry of Environment and recent AI-based forest degradation classification. The tree species of each point were checked by the 2008 North Korean vegetation map and grouped by Maple (Acer mono), Oak (Quercus mongolica), Fir (Abies nephrolepis), and Pine (Pinus densiflora) trees. This study configured current climate data (1960-2010), RCP 4.5, and 8.5 climate scenarios (2011-2100). In addition, vegetation characteristics, soil properties, deforestation information, and reforestation assumptions were selected and fit the Biogeochemistry Management (BGC-MAN) model. In the results, the NPP values were around 3.879-7.169 Mg C ha^-1 in 2020, and they changed to 4.774-9.595 in 2100 in both RCP scenarios at each point. The annual average NPP values of 2020 were evaluated at 5.174 and 5.179 Mg C ha^-1 in RCP 4.5 and 8.5 scenarios, and the values of 2100 were evaluated at 6.135 and 6.148 in each scenario. Considering the NPP values from the satellite, the overall values were in the range of the NPP data from the satellite-based assessment. The potential net primary productivities were as good as South Korea, which had successful reforestation history. Therefore, proper ecological management planning was necessary using the process-based model, and more in-depth research would be required for North Korean forest management.

How to cite: Song, C., Pietsch, S. A., Kim, J., Choi, H.-A., and Lee, W.-K.: Assessing net primary productivity in tree nursery points of North Korea using biogeochemistry model, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10878, https://doi.org/10.5194/egusphere-egu23-10878, 2023.

A.235

EGU23-5651

ECS

On-site presentation

Forest disturbance detection using deep learning approaches

Franziska Müller, Laura Häbold, Vitus Benson, Markus Reichstein, and Ana Bastos

Fire, wind, drought, and insect outbreaks are causing rapid forest decline worldwide. In recent years, the number of forest losses due to such disturbance events has reportedly increased in the temperate and southern boreal regions. However, there is a lack of large-scale and long-term observational records of different disruption types that would link forest stress and mortality to a specific cause of disturbance. Therefore, it is difficult to understand the temporal development of the various forest disturbances and to attribute these signs with certainty to climate change. The increase in quantity and quality of remote sensing data at high spatial and temporal resolutions, along with advances in machine learning for environmental applications, hold great promise for distinguishing between these different disturbance types.

Our conceptual plan for implementing the research is centered on using Sentinel 2 reflectance data and constructing different deep-learning models to identify disturbance types over a case-study region in North America. We focus on large wind throw and bark beetle outbreaks in the construction of a comprehensive data set. The relevance of different features for distinguishing between these two disturbance types is evaluated by comparing spatial and temporal patterns, as well as the relative importance of different reflectance bands.

How to cite: Müller, F., Häbold, L., Benson, V., Reichstein, M., and Bastos, A.: Forest disturbance detection using deep learning approaches, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5651, https://doi.org/10.5194/egusphere-egu23-5651, 2023.

A.236

EGU23-15925

ECS

On-site presentation

Evaluating the consistency of different forest disturbance datasets

Laura Häbold and Ana Bastos

Forest health and disturbance data are crucial to improve our understanding about impacts of climate change on the multiple services forests provide (CO2 sequestration, water cycling, timber production, recreation and culture, etc.). Recently, several new datasets with different acquisition methods and at different spatial and temporal scaleshave become available. While such datasets provide invaluable information, the consistency of the information they provide needs to be evaluated.

The aim of this study is to evaluate the consistency of three publicly available tree mortality and disturbance datasets. We compared the consistency of the datasets in terms of their reported timing and the driving disturbance agents for events occurring from 2000 to 2021. Preliminary results indicate some overlap of disturbance events, but with important temporal lags between different datasets. An exact overlap in space and time is rare, which might be due to different acquisition methods as well as the spatial scale and magnitude of the disturbance.

How to cite: Häbold, L. and Bastos, A.: Evaluating the consistency of different forest disturbance datasets, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15925, https://doi.org/10.5194/egusphere-egu23-15925, 2023.

A.238

EGU23-10774

ECS

On-site presentation

Assessing spatiotemporal resolution of variables in landscape-scale species distribution models

Nicolò Anselmetto, Matthew Betts, Matthew Weldy, Marie Tosa, Joseph LaManna, Hankyu Kim, Damon Leismeister, Clinton Epps, David Bell, Mark Schulze, Christopher Daly, and Matteo Garbarino

The strategic importance of biodiversity conservation is increasing all over the world to face the threats that the global change bring to forest ecosystems. To accomplish that, Species Distribution Models (SDMs) stand as the most employed statistic models in ecological conservation. Nevertheless, explanatory predictors in these correlative models usually consist in free-air climate variables with coarse spatial (>1 km) and temporal (average of several years) resolution. This approach neglects the real habitat conditions experienced by most of the organisms on their life span. Hence, improving the reliability of these ecological models is crucial for biologists, land managers, and policymakers.

Our aim was to compare microclimate temperatures derived from 13 years (2010-2022) of below-canopy hourly data loggers to free-air macroclimate derived from a mechanistic downscaling of global reanalysis data at 30 arcsec (CHELSA). We also tested the role of LiDAR-derived vegetation metrics to improve fine-scale SDMs. We developed three sets of predictors based on their temporal resolution: 1) an average across the years of observation based on the general presence or absence of the species, 2) an ensemble of year models (i.e., the average of the probability for each year weighted on its accuracy), and 3) a random year of observation.

Using Bayesian Additive Regression Tree (BART) algorithms, we built SDMs for different species of birds, plants, insects, and mammals in a temperate rainforest landscape of the Pacific Northwest (HJ Andrew Experimental Forest, Oregon, United States). We built 12 different modeling frameworks based on the combination between climate input data (microclimate vs macroclimate), vegetation (with vs without), and temporal resolution (average vs ensemble vs random).

We measured the distance between the probability distribution obtained from the different combinations using the Kolmogorov-Smirnov distance. We evaluated and compared three accuracy metrics of the models (AUC, TSS, MCS) through a 5-fold spatial block cross-validation. We tested for differences in distance and accuracy both at the taxa level and on ecological traits of the different species (mobility, prevalence, specialization).

Preliminary results for bird species showed that temporal resolution was more important than climate datasets when including vegetation variables in the models. Some insect species showed a greater improvement in accuracy for models trained with microclimate compared to models trained with CHELSA.

How to cite: Anselmetto, N., Betts, M., Weldy, M., Tosa, M., LaManna, J., Kim, H., Leismeister, D., Epps, C., Bell, D., Schulze, M., Daly, C., and Garbarino, M.: Assessing spatiotemporal resolution of variables in landscape-scale species distribution models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10774, https://doi.org/10.5194/egusphere-egu23-10774, 2023.

Posters virtual: Thu, 27 Apr, 14:00–15:45 | vHall BG

The posters scheduled for virtual presentation are visible in Gather.Town. Attendees are asked to meet the authors during the scheduled attendance time for live video chats. If authors uploaded their presentation files, these files are also linked from the abstracts below, but only on the day of the poster session. The button to access Gather.Town appears just before the time block starts.

Chairpersons: Raffaella Marzano, Emanuele Lingua, Matteo Garbarino

vBG.5

EGU23-6326

ECS

Virtual presentation

Digging up into windstorms aftermath: understanding the effect of harvesting systems on salvage logging wood residues spatial distribution

Alberto Udali, Sara Cucchiaro, Emanuele Lingua, and Stefano Grigolato

Extreme disturbance events, such as climate change-driven ones, have increased their frequency, upsetting the ordinary management of forests, and impacting large areas with severe damage. As a consequence, when productive forests are hit, salvage logging operations represent the common way to recover part of the economic loose. However, salvage logging can lead to negative impacts in terms of soil erosion as well in terms of variation of soil carbon stock and nutrients. Commonly, in the European Alps, salvage logging operations in largely damaged forest areas can be referred generally to as two harvesting systems: i) Cut-to-Length (CTL) and ii) Full-Tree (FT) extraction systems.

The application of the two harvesting systems can have a different effect on the type and quantity of logging residues and deadwood left on the forest ground, which in the short-medium term it can be reflected in terms of quantity and distribution of organic carbon and nutrients in the soil.

To evaluate and gather more detailed information on the effects of forest operations, a valuable option is to rely on the use of precision forestry approaches, such as the use of remote sensing (RS) and Artificial Intelligence applications, for example, machine learning (ML). In the realm of forest operations, ML techniques and algorithms are the most used and can be fed with data directly extracted from the machines operating live on sites, and also with data retrieved through RS. Drone-borne data, for example, is now becoming the most used for its large potential and applicability, providing both large coverage and a high level of detail oversampled areas.

The aim of this study is thus comparing two salvage logging areas and find any difference in terms of logging residue type, quantity, and spatial distribution according to the used harvesting system.

Drone flights over two logging areas in the northeastern Alps to retrieve logging residues data were performed in 2022, the sites were windthrown in 2018 and harvested in 2021. A random forest model was built using RGB bands derived from the drone images, textural variables, and information from the surface model to classify elements in a clear-felled site. After the classification and noise removing operations, residues mass per hectare and distribution were estimated.

Preliminary results will show the strengths and weaknesses of the method adopted in assessing the type of residues and their spatial distribution. Moreover, this application will highlight the different impacts of the two systems adopted in salvage logging operations with respect to residue type and quantity left on site.

How to cite: Udali, A., Cucchiaro, S., Lingua, E., and Grigolato, S.: Digging up into windstorms aftermath: understanding the effect of harvesting systems on salvage logging wood residues spatial distribution, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6326, https://doi.org/10.5194/egusphere-egu23-6326, 2023.