Economic perspectives on landscape connectivity and collaboration in bark beetle management

Background:

As climate change accelerates, Norway spruce forests are increasingly affected by spruce bark beetle (Ips typographus) calamities (Seidl and Rammer, 2017; Seidl et al. 2014). Recently observed bark beetle outbreaks - associated with storms (trigger) and droughts (vulnerability) in Central Europe (Buras et al., 2020; Schuldt et al., 2020) - show the unprecedented impact on ecosystem service provision.

There are different approaches for bark beetle management: Proactive, long-term adaptation of forests vs. reactive outbreak control (cf., Hlásny et al., 2019). Fuchs et al. (2021) showed that in the long run, from a purely economic, risk-averse perspective, proactive adaptation of tree-species composition is more promising than an intensive bark beetle monitoring with sanitation fellings. The study is, however, (1) limited to the spatial scale of a single stand and (2) assumes that there are alternative, highly productive conifers that are much less/not affected by the bark beetle. Studies by Dobor et al. (2020) and Honkaniemi et al. (2020) suggest that configuration (i.e., the spatially explicit allocation of stand types in the forest enterprise/landscape) may have a similar or even higher dampening effect on the spread of pests. For instance, when allocating Norway spruce stands in a matrix of European beech, the probability of finding a new host tree decreases; the landscape connectivity for bark beetles is lower.

Applying this management approach to a spruce forest would drastically reduce the area share of this conifer. Maintaining remarkable area shares of highly productive conifers is, however, important for many provisioning ecosystem services (and to some extent also other services, such as carbon sequestration). A forest manager thus faces the problem of selecting a reasonable mix of adaptation strategies based on (1) species composition, (2) species configuration, and (3) reactive sanitation cuts. This decision likely interacts with the assumed probability of future storm events triggering bark beetle outbreaks. In addition, coordinated long-term management decisions at the landscape level are often hampered by the small ownership sizes typical for Central European private forests.

Research questions:

1.     Does tree-species configuration perform better than tree-species composition and intensive bark beetle monitoring with timely sanitation felling in terms of its ability to reduce economic losses in wood production due to bark beetle infestations?

2.     To what extent do the different management strategies interact? Are there relevant synergies?

3.     To what extent can such adaptation gains be realized under increasing probabilities of storm events?

4.     How important is cooperation between decision-makers in a landscape of small ownerships for the individual owner's adaptation gain?

Methods:

The thesis incorporates building a simulation model applying the concept of cellular automata. The forest landscape is divided into patches (grid cells). Each forest patch's future state (age of the forest, wind damage, bark beetle infestation) depends on its own state as well as on the state of the neighboring patches. This allows for implementing landscape connectivity for bark beetle outbreaks. The cellular automata can be built in NetLogo¹⁾. NetLogo is a beginner-friendly programming language for patch models and agent-based models. NetLogo allows for easily defining a landscape of forest patches with rule sets for their development and creating a graphical user interface.

The model should include a (simple) forest growth simulation, storm events, probabilities for bark beetle outbreaks and their influence on neighboring patches, decision rules for forest management, and an economic valuation module. On this basis it is possible to simulate different landscapes, management scenarios, scenarios of cooperation between forest owners, and sensitivity analyses.

¹⁾NetLogo is designed to be easy to learn and provides relevant features without having to implement them from scratch. For a first idea visit external page https://ccl.northwestern.edu/netlogo/ and refer to the well-designed tutorials.

Wanted:

We search for a highly motivated student interested in forest management, simulation modeling, and forest economics. We will ask you to familiarize yourself with NetLogo to implement the model. Some background in forest growth and bark beetle ecology/management is recommended or needs to be acquired. You should be interested in implementing/applying valuation concepts for economic risk and return. Skills in R or Python may be helpful for the data analysis/plotting, Excel is the minimum requirement.

The project has a flexible starting date.

You will get to:

• Deepen your knowledge about socioeconomical perspectives on forest management.
• Gain experience in programming, simulation modeling, and scenario analysis.
• Be a co-author on a publication resulting from this work.
• Be part of a motivated team of scientists.

Supervisor:

Dr. Jasper Fuchs, Prof. Dr. Verena Griess

If the idea of participating in cutting-edge interdisciplinary research excites you, please contact jasper.fuchs(at)usys.ethz.ch. The FORM team is looking forward to hearing from you!

References:

Buras, A., Rammig, A., Zang, C.S., 2020. Quantifying impacts of the 2018 drought on European ecosystems in comparison to 2003. Biogeosciences 17, 1655–1672. doi:10.5194/bg-17-1655-2020.

Dobor, L., Hlásny, T., Rammer, W., Zimová, S., Barka, I., Seidl, R., 2020. Spatial configuration matters when removing windfelled trees to manage bark beetle disturbances in Central European forest landscapes. J. Environ. Manage. 254, 109792. doi:10.1016/j.jenvman.2019.109792.

Fuchs, J.M., Hittenbeck, A., Brandl, S., Schmidt, M., Paul, C., 2021. Adaptation strategies for spruce forests—economic potential of bark beetle management and Douglas fir cultivation in future tree species portfolios. Forestry doi:10.1093/forestry/cpab040.

Hlásny, T., Krokene, P., Liebhold, A., Montagné-Huck, C., Müller, J., Qin, H., Raffa, K.F., Schelhaas, M.J., Seidl, R., Svoboda, M., Viiri, H., 2019. Living with Bark Beetles: Impacts, Outlook and Management Options. volume 8 of From Science to Policy / European Forest Institute. European Forest Institute, Joensuu.

Honkaniemi, J., Rammer, W., Seidl, R., 2020. Norway spruce at the trailing edge: The effect of landscape configuration and composition on climate resilience. Landscape Ecol 35, 591–606. doi:10.1007/s10980-019-00964-y.

Schuldt, B., Buras, A., Arend, M., Vitasse, Y., Beierkuhnlein, C., Damm, A., Gharun, M., Grams, T.E., Hauck, M., Hajek, P., Hartmann, H., Hiltbrunner, E., Hoch, G., Holloway-Phillips, M.,Körner, C., Larysch, E., Lübbe, T., Nelson, D.B., Rammig, A., Rigling, A., Rose, L., Ruehr, N.K., Schumann, K., Weiser, F., Werner, C., Wohlgemuth, T., Zang, C.S., Kahmen, A., 2020. A first assessment of the impact of the extreme 2018 summer drought on Central European forests. Basic Appl. Ecol. 45, 86–103. doi:10.1016/j.baae.2020.04.003.

Seidl, R., Rammer, W., 2017. Climate change amplifies the interactions between wind and bark beetle disturbances in forest landscapes. Landscape Ecol 32, 1485–1498. doi:10.1007/s10980-016-0396-4.

Seidl, R., Schelhaas, M.J., Rammer, W., Verkerk, P.J., 2014. Increasing forest disturbances in Europe and their impact on carbon storage. Nat. Clim. Change 4, 806–810. doi:10.1038/nclimate2318.