Release: The Bark Beetle Dashboard

Bark beetles benefit from climate change and are presently the most important insect pests in Austrian forests. The bark beetle dashboard supports risk assessment for infestation of forest stands by the Eurasian spruce bark beetle according to the latest state of knowledge. For this purpose, simulations of bark beetle phenology and development by the model PHENIPS, which is already established in forestry practice, and other systems for risk assessment are made freely accessible on a geoserver. In addition to the daily updated spruce bark beetle development status, the dashboard provides information on the current water supply of forests, the site- and stand-related susceptibility of forests to bark beetle infestation and the amount of damaged timber in the past year.

The new bark beetle dashboard provides essential and innovative decision-support for deriving forestry measures and adaptation strategies at various levels in the face of man-made climate change:

• Identification of hotspots with increased site-specific vulnerability and acute infestation risks due to the current forest cover
• Early detection and sanitation of bark beetle infestations, e.g. through knowledge of the current development state and drought stress conditions
• Medium and long-term forest conversion into climate-adapted mixed forests
• Development and professional evaluation of nationwide forest adaptation and mitigation strategies

Effective measures to prevent and mitigate damage caused by bark beetles are urgently needed. While bark beetle damage has decreased in the north of Austria (Waldviertel and Mühlviertel), mass outbreaks of I. typographus continue to occur in East Tyrol and Upper Carinthia. In addition, a further outbreak hotspot developed in the north-eastern part of Upper Styria. According to the BFW's documentation of forest damaging factors, the damage caused by bark beetles throughout Austria amounted to around 4 million cubic meters (m³) in 2023. In East Tyrol, unprecedented amounts of damage of almost 18 m³ per hectare of forest area were reported, which exceed the annual wood growth of the forests by a multiple. This development shows that not only in secondary spruce forests at lower altitudes, but also in near-natural spruce forests at montane and high montane/subalpine altitudes, bark beetle outbreaks can occur on a large scale.

The bark beetle dashboard was developed as part of two research projects in cooperation of BOKU University and BFW to support bark beetle management in times of rising temperatures and recurring drought and storm events. The PHENIPS plus project is aimed at advancing the bark beetle development model PHENIPS, while the RAWLog project is developing a new predisposition assessment system (PAS) for forests against bark beetle attacks, based primarily on remote sensing data, in combination with an assessment of the hauling and transport situation of damaged wood.

Bark Beetle development using PHENIPS

PHENIPS models the development of the spruce bark beetle using meteorological data such as air temperature and solar radiation. The calculations are based on climate data from GeoSphere Austria. The current development status of the spruce bark beetle, a forecast of further development (+28 days) and the generation development of previous years are shown for entire Austria. Furthermore, detailed development curves of the individual generations can be accessed at the GeoSphere Austria climate stations.

Drought as a cause of bark beetle outbreaks

Current studies on spruce bark beetle outbreaks clearly show that drought stress is an increasingly important factor triggering the successful colonization of Norway spruce. The bark beetle dashboard therefore uses the daily updated climatic drought index SPEI (Standardized Precipitation Evapotranspiration Index) of the past 30 and 90 days provided by Geosphere Austria to estimate the current water supply of forests. Combined modelling of spruce bark beetle development and evaluation of drought allows to identify times when dispersal of the insects and tree stress coincide. In the medium term, we plan to supplement SPEI by detailed modeling of the water balance at selected case study sites.

Susceptibility (predisposition) of spruce forests to bark beetle outbreaks

For estimating the predisposition of forests to bark beetle infestation, an already established model (Predisposition Assessment System: PAS) was adapted to the high-resolution remote sensing data available for Austria. This model takes into account a large number of influencing factors, some of which characterize the susceptibility of the site (especially soil and climate), such as the possible number of generations of spruce bark beetles in recent years, the terrain morphology or the climatic water balance during the vegetation period. The second part describes the susceptibility of the forest stand, which is influenced, for example, by the spruce proportion, tree height or previous disturbances (e.g, damage by wind and snow, which facilitate an eruptive increase of bark beetle populations). The further development of PAS was made possible by innovative remote sensing products from BFW, such as the new tree species and anomaly maps (which show changes of the forest structure due to timber utilization, windthrow or bark beetle infestation), which were derived from satellite image data (Sentinel-2 time series) using machine learning algorithms. The predisposition maps are displayed with a high spatial resolution of 10 m and are updated annually.

Outlook

The current test version of the bark beetle dashboard will be continuously developed further. Among other things, the model for estimating the hauling and transport situation of damaged wood is currently under development and the implementation of a water balance model is planned by the end of 2024.

An automatic adaptation of the layout depending on the screen size enables use on laptops as well as on tablets and smartphones in the forest. The larger the screen, the more functions are accessible. Test the dashboard:

https://ifff-riskanalyses.boku.ac.at/borkenkaefer_dashboard.htm

This research has been carried out with the financial support of the Federal Ministry of Agriculture, Forestry, Regions and Water Management (BML), the provincial governments of the Austrian provinces and the cooperation platform Forst Holz Papier: Waldfonds WF M4 / Application No. BMLRT/III-2021-M4/2 (FAI.2) Project RAWLog and DaFNE Research Project No. 101557 PHENIPS plus.

Project team:

Till Hallas^1,2, Sigrid Netherer², Thomas Kirisits², Peter Baier², Josef Pennerstorfer², Tobias Schadauer³, Susanne Karel³, Klemens Schadauer³, Gernot Hoch¹

¹Austrian Research Centre for Forests (Department of Forest Protection)

²BOKU University (Institute of Forest Entomology, Forest Pathology and Forest Protection)

³Austrian Research Centre for Forests (Department of Forest Inventory)

Further Information:

Baier, P., J. Pennerstorfer and A. Schopf (2007). "PHENIPS—A comprehensive phenology model of Ips typographus (L.) (Col., Scolytinae) as a tool for hazard rating of bark beetle infestation." Forest Ecology and Management 249(3): 171-186.

Bundesforschungszentrum für Wald (2024). „Documentation of Forest Damage Factors”, BFW, Vienna. Online: https://www.bfw.gv.at/dokumentation-waldschaedigungsfaktoren

Hallas, T., S. Netherer, T. Kirisits, P. Baier, J. Pennerstorfer, T. Schadauer, S. Karel, K. Schadauer and G. Hoch (2024). „Tagesaktuelle Borkenkäfer-Trends.“ Forstzeitung.at. Wien, Österreichischer Agrarverlag. 07/2024: 22-24. https://www.forstzeitung.at/markt/2024/07/borkenkaefer-dashboard.html

Hallas, T., S. Netherer, J. Pennerstorfer, S. Karel, T. Schadauer, M. Löw, P. Baier, C. Bauerhansl, D. Kessler, M. Englisch, C. Huber, N. Nemesthoty, T. Kirisits, K. Schadauer and G. Hoch (2024). “The Bark Beetle Dashboard - towards a holistic risk assessment of Ips typographus.” 26. IUFRO World Congress. Stockholm 2024.

Hallas, T., G. Steyrer, G. Laaha and G. Hoch (2024). "Two unprecedented outbreaks of the European spruce bark beetle, Ips typographus L. (Col., Scolytinae) in Austria since 2015: Different causes and different impacts on forests." Central European Forestry Journal: 1-12.

Löw, M. and T. Koukal (2020). "Phenology Modelling and Forest Disturbance Mapping with Sentinel-2 Time Series in Austria." Remote Sensing 12(24).

Netherer, S. and U. Nopp-Mayr (2005). "Predisposition assessment systems (PAS) as supportive tools in forest management—rating of site and stand-related hazards of bark beetle infestation in the High Tatra Mountains as an example for system application and verification." Forest Ecology and Management 207(1-2): 99-107.

Schadauer, T., S. Karel, M. Löw, U. Knieling, K. Kopecky, C. Bauerhansl, A. Berger and L. Winiwarter (2024, preprint, under review). "Unraveling Forest Diversity:Sentinel-2 Time Series Neural Networks for National-Scale Tree Species Mapping with Pure and Mixed Classes, Validated Via Probability Sampling." SSRN.

Contact

Till Hallas
M.Sc. M.Sc. • PhD candidate and research assistant
BOKU University & Austrian Research Centre for Forests (BFW)
till.hallas@boku.ac.at