The SwissForestLab is a research platform and infrastructural network. By making intensive use of synergies from the expertise in forest research in Switzerland we promote cooperative research in order to obtain an in-depth understanding of ecosystem functioning, resistance and resilience of forests.
In Switzerland, scientists with an excellent expertise in the field of forest research are working in various institutions and in different disciplines. In addition, there is a wide range of infrastructure and approaches established by Swiss research institutions and Universities:
Field sites (networks, monitoring and experiments)
Installations like cranes and measurement towers etc.
Data from field and laboratory analyses and monitoring
Specific laboratories and methods
Various experimental and modelling approaches
The idea of the SwissForestLab is to bring together these elements within a network. This network allows for synergies and new insights and findings in science as well as a better visibility of existing expertise and infrastructure and the possibility to find new cooperation partners. New and innovative interdisciplinary experiments and projects can be established within this network and finally the visibility of Swiss forest research worldwide will be increased.
Who we are
The SwissForestLab, initiated by WSL, started with a group of idea drivers from different Swiss institutions (ETH, Universities of Zurich, Bern, Basel and WSL). This “starting group” is comprised of researchers working together in the initial SwissForestLab phase to set up all necessary steps for the establishment of the network.
With the official start of the SwissForestLab in September 2017 the platform is now open for all researchers working in the field of forest ecosystem research in Switzerland and contributing with infrastructure (data, field sites, models etc.) to the network to be a member of the SwissForestLab.
With this growing group of members we create a dynamic scientific environment with additional strong focus on outreach and applied research. In addition to members, the SwissForestLab is also open to partners like international cooperation affiliates within joint research projects or members of federal agencies, companies or foundations.
WSL funds and hosts the research coordination of the SwissForestLab.
THE EFFECTS OF DROUGHT ON THE INTERACTION BETWEEN CARBON AND NITROGEN RELATIONS IN TREES
Corresponding authors: Arthur Gessler and Jobin Joseph
The Global Climate Change is projected to increase the frequency and intensity of weather extremes in Central Europe. As one consequence extreme drought events will occur more often with potential negative effects on the growth and performance of trees and forest ecosystems. Mainly two complementing mechanisms leading to growth impairment, reduction of physiological performance and mortality upon drought are discussed at present, namely hydraulic failure (as a result of xylem embolisms) and carbon starvation (due to insufficient photosynthetic carbon assimilation). In addition, the negative impacts of drought on nutrient uptake may lead to disturbed nutrient balance of trees and ecosystems. Hence, nutrient uptake is an additional important parameter affecting tree performance under drought and there is only little information available on the underlying mechanisms. The research proposed here will thus shed light on the effects of drought and recovery from drought on the nitrogen uptake of trees. Nitrogen is the major growth limiting nutrient in natural temperate terrestrial ecosystems and has thus been chosen as model nutrient. The proposed project consists of three modules: in module 1 we will screen the importance of physiological restrictions of nitrogen uptake capacity (Jmax (maximum ammonium and nitrate net uptake capacity) and C50 (nitrate or ammonium concentration where 50% of the maximum net uptake is observed)) under drought for seven different tree species. Module 1 will also assess the plasticity of tree species to compensate for a decreased soil nitrogen availability with biomass allocation to the mycorrhizal fine roots. Module 2 will build upon this screening and consist of an in-depth analysis of the mechanisms that control the nitrogen uptake capacity under restricted water supply, with a particular focus on the interplay between transport of recent assimilates belowground and nitrogen uptake. In module 3, we will extend the mechanistic analysis of module 2 to the phase of recovery from drought and will focus on the re-establishment of transport of recent assimilates and nitrogen uptake capacity. By linking nutrient uptake with the carbon and water balance this work will complement and extend the existing conceptual models on drought effects on tree physiology.
Predicting Ozone Fluxes, Impacts, and Critical Levels on European Forests
Corresponding author: Marcus Schaub
Tropospheric ozone (O3) is considered to be more damaging to vegetation than any other air pollutant. Public concerns, evidence from research, and increasing scientific knowledge are all driving widespread discussions on ozone risk assessment and dose-response relationships for European forests. In particular, there is high uncertainty concerning the effect of ozone on individual tree diameter increment and forest growth. However, the contrasting results may arise from the different data used as input in terms of sample size and characteristics, and/or from differing methodological choices. This study therefore aims to make use of over 200 long-term monitoring plots across Europe where ozone concentrations have been measured since 2000, in parallel to forest and vegetation variables. Ozone related effects and critical levels on selected endpoints such as tree growth will be derived by quantifying ozone fluxes, and by (i) applying multiple and various statistical techniques that also consider for other abiotic and biotic environmental factors. The outputs will be validated and up-scaled in space and time by (ii) developing an “Ozone-version” of the physiological process-based model CASTANEA, and (iii) coupling the DO3SE model with the forest succession (“gap”) model ForClim. Data sources from various networks will be explored and applied for model calibrations, validations, and applications. The outlined ensemble of statistical and mechanistic model simulations will allow us to detect environmental tipping points leading to strong decrease in stand productivity. This allows for the determination of species-specific, site-specific, and climate change-specific critical ozone levels, which will be an important contribution to the objectives of the UNECE WG on Effects.
Quantifying, understanding and predicting forest growth in Switzerland
Corresponding author: Werner Eugster
Forests world-wide are known as an important net carbon sink and are thus a key component of the terrestrial carbon cycle. However, carbon fluxes and storage vary regionally and with inter-annual to long-term environmental change. A higher frequency of drought events and other negative impacts on growth (increased autotrophic respiration and disturbances) are predicted to outweigh enhanced productivity as a result of increasing temperatures or CO2 and nitrogen fertilization. Existing models of forest growth dynamics include large uncertainties, which ramify and lead to divergence in forecasts how climate change will impact the future terrestrial carbon cycle. To reduce these uncertainties, it is necessary to extend and combine assessments of current observation networks using novel analytical approaches and data sources. Swiss forests are of particular interest: the climatic, pedologic and biogeographical conditions of Switzerland correspond closely with the European gradient, on a relatively small geographical scale. WSL and its partners own a wealth of diverse data on forest growth and health in Switzerland. We plan to exploit this data treasure in our SwissForestLab project. Our aim is to estimate Swiss forest net ecosystem productivity (NEP) at monthly or seasonal resolution in order to link biomass changes over time with global drivers (climate, soils, landscapes, N deposition). We hypothesize that a combination of available high-quality long-term data sets provides an excellent data basis for a data-model-fusion approach within SwissForestLab. This activity is expected (a) to merge data with different temporal and spatial resolution so that they can be used more easily by SwissForestLab members, and (b) to provide a first visible result from SwissForestLab that will foster follow-up research projects focusing on different aspects of forest growth and development.
Kälin, U.; Lang, N.; Hug, C.; Gessler, A.; Wegner, J.D., 2019: Defoliation estimation of forest trees from ground-level images. Remote Sensing of Environment, 223: 143-153. doi: 10.1016/j.rse.2018.12.021
Baeten, L.; Bruelheide, H.; Van der Plas, F.; Kambach, S.; Ratcliffe, S.; Jucker, T.; Allan, E.; Ampoorter, E.; Barbaro, L.; Bastias, C.C.; Bauhus, J.; Benavides, R.; Bonal, D.; Bouriaud, O.; Bussotti, F.; Carnol, M.; Castagneyrol, B.; Charbonnier, Y.; Chećko, E.; ... Scherer-Lorenzen, M., 2018: Identifying the tree species compositions that maximize ecosystem functioning in European forests. Journal of Applied Ecology, doi: 10.1111/1365-2664.13308
Weber, R.; Gessler, A.; Hoch, G., 2018: High carbon storage in carbon-limited trees. New Phytologist, doi: 10.1111/nph.15599
Lanza, G.; Stang, A.; Kern, J.; Wirth, S.; Gessler, A., 2018: Degradability of raw and post-processed chars in a two-year field experiment. Science of the Total Environment, 628-629: 1600-1608. doi: 10.1016/j.scitotenv.2018.02.164
Resco de Dios, V.; Gessler, A., 2018: Circadian regulation of photosynthesis and transpiration from genes to ecosystems. Environmental and Experimental Botany, 152: 37-48. doi: 10.1016/j.envexpbot.2017.09.010
Bussotti, F.; Pollastrini, M.; Gessler, A.; Luo, Z., 2018: Experiments with trees: from seedlings to ecosystems. Environmental and Experimental Botany, 152: 1-6. doi: 10.1016/j.envexpbot.2018.04.012
Niedermann, S.; Gessler, A., 2018: Waldschäden frühzeitig erkennen. WSL-Magazin Diagonal, 2018, 2: 12-14.
Niedermann, S.; Gessler, A., 2018: Détection précoce des dégâts en forêt. Magazine du WSL Diagonale, 2018, 2: 12-14.
Niedermann, S.; Gessler, A., 2018: Detecting forest damage early. WSL magazine Diagonal, 2018, 2: 12-14.
Kiorapostolou, N.; Galiano-Pérez, L.; Von Arx, G.; Gessler, A.; Petit, G., 2018: Structural and anatomical responses of Pinus sylvestris and Tilia platyphyllos seedlings exposed to water shortage. Trees: Structure and Function, 32, 5: 1211-1218. doi: 10.1007/s00468-018-1703-2
Gessler, A., 2018: Editor's highlight for TSAF D-17-00396: carbon and oxygen isotopes in tree rings – climate signals and microsite effects. Trees: Structure and Function, 32, 3: 881-882. doi: 10.1007/s00468-018-1681-4
Gessler, A.; Reed, S.C.; Borrego, I.; Collins, A.D.; Dickman, L.T.; Ryan, M.; Schönbeck, L.; Sevanto, S.; Vilagrosa, A.; McDowell, N.G., 2018: Reductions in tree performance during hotter droughts are mitigated by shifts in nitrogen cycling. Plant, Cell and Environment, 41, 11: 2627-2637. doi: 10.1111/pce.13389
Nussbaumer, A.; Waldner, P.; Apuhtin, V.; Aytar, F.; Benham, S.; Bussotti, F.; Eichhorn, J.; Eickenscheidt, N.; Fabianek, P.; Falkenried, L.; Leca, S.; Lindgren, M.; Manzano Serrano, M.J.; Neagu, S.; Nevalainen, S.; Pajtik, J.; Potočić, N.; Rautio, P.; Sioen, G.; ... Gessler, A., 2018: Impact of weather cues and resource dynamics on mast occurrence in the main forest tree species in Europe. Forest Ecology and Management, 429: 336-350. doi: 10.1016/j.foreco.2018.07.011
He, P.; Fontana, S.; Sui, X.; Gessler, A.; Schaub, M.; Rigling, A.; Jiang, Y.; Li, M., 2018: Scale dependent responses of pine reproductive traits to experimental and natural precipitation gradients. Environmental and Experimental Botany, 156: 62-73. doi: 10.1016/j.envexpbot.2018.08.028
Van der Plas, F.; Ratcliffe, S.; Ruiz-Benito, P.; Scherer-Lorenzen, M.; Verheyen, K.; Wirth, C.; Zavala, M.A.; Ampoorter, E.; Baeten, L.; Barbaro, L.; Bastias, C.C.; Bauhus, J.; Benavides, R.; Benneter, A.; Bonal, D.; Bouriaud, O.; Bruelheide, H.; Bussotti, F.; Carnol, M.; ... Allan, E., 2018: Continental mapping of forest ecosystem functions reveals a high but unrealised potential for forest multifunctionality. Ecology Letters, 21, 1: 31-42. doi: 10.1111/ele.12868
Wohlgemuth, T.; Forster, B.; Gessler, A.; Ginzler, C.; Queloz, V.; Vitasse, Y.; Rigling, A., 2018: Sommertrockenheit. Zunehmend eine Herausforderung für den Wald. Wald und Holz, 99, 9: 18-19.
Felsmann, K.; Baudis, M.; Kayler, Z.E.; Puhlmann, H.; Ulrich, A.; Gessler, A., 2018: Responses of the structure and function of the understory plant communities to precipitation reduction across forest ecosystems in Germany. Annals of Forest Science, 75, 1: 3 (18 pp.). doi: 10.1007/s13595-017-0681-7
Schönbeck, L.; Gessler, A.; Hoch, G.; McDowell, N.G.; Rigling, A.; Schaub, M.; Li, M., 2018: Homeostatic levels of nonstructural carbohydrates after 13 yr of drought and irrigation in Pinus sylvestris. New Phytologist, 219, 4: 1314-1324. doi: 10.1111/nph.15224
Jesch, A.; Barry, K.E.; Ravenek, J.M.; Bachmann, D.; Strecker, T.; Weigelt, A.; Buchmann, N.; De Kroon, H.; Gessler, A.; Mommer, L.; Roscher, C.; Scherer-Lorenzen, M., 2018: Below-ground resource partitioning alone cannot explain the biodiversity–ecosystem function relationship: a field test using multiple tracers. Journal of Ecology, 106, 5: 2002-2008. doi: 10.1111/1365-2745.12947
Gessler, A.; Cailleret, M.; Joseph, J.; Schönbeck, L.; Schaub, M.; Lehmann, M.; Treydte, K.; Rigling, A.; Timofeeva, G.; Saurer, M., 2018: Drought induced tree mortality - a tree-ring isotope based conceptual model to assess mechanisms and predispositions. New Phytologist, 219, 2: 485-490. doi: 10.1111/nph.15154
Cailleret, M.; Ferretti, M.; Gessler, A.; Rigling, A.; Schaub, M., 2018: Ozone effects on European forest growth - towards an integrative approach. Journal of Ecology, 106, 4: 1377-1389. doi: 10.1111/1365-2745.12941
Rebetez, M.; Von Arx, G.; Gessler, A.; Pannatier, E.G.; Innes, J.L.; Jakob, P.; Jetel, M.; Kube, M.; Nötzli, M.; Schaub, M.; Schmitt, M.; Sutter, F.; Thimonier, A.; Waldner, P.; Haeni, M., 2018: Meteorological data series from Swiss long-term forest ecosystem research plots since 1997. Annals of Forest Science, 75, 2: 41 (7 pp.). doi: 10.1007/s13595-018-0709-7
Engelhardt, I.C.; Welty, A.; Blazewicz, S.J.; Bru, D.; Rouard, N.; Breuil, M.; Gessler, A.; Galiano, L.; Miranda, J.C.; Spor, A.; Barnard, R.L., 2018: Depth matters: Effects of precipitation regime on soil microbial activity upon rewetting of a plant-soil system. ISME Journal, 12, 4: 1061-1071. doi: 10.1038/s41396-018-0079-z
Du, B.; Kreuzwieser, J.; Dannenmann, M.; Junker, L.V.; Kleiber, A.; Hess, M.; Jansen, K.; Eiblmeier, M.; Gessler, A.; Kohnle, U.; Ensminger, I.; Rennenberg, H.; Wildhagen, H., 2018: Foliar nitrogen metabolism of adult Douglas-fir trees is affected by soil water availability and varies little among provenances. PLoS One, 13, 3: e0194684 (24 pp.). doi: 10.1371/journal.pone.0194684
Wieloch, T.; Ehlers, I.; Yu, J.; Frank, D.; Grabner, M.; Gessler, A.; Schleucher, J., 2018: Intramolecular 13C analysis of tree rings provides multiple plant ecophysiology signals covering decades. Scientific Reports, 8, 1: 5048 (10 pp.). doi: 10.1038/s41598-018-23422-2
Hartmann, H.; Moura, C.F.; Anderegg, W.R.L.; Ruehr, N.K.; Salmon, Y.; Allen, C.D.; Arndt, S.K.; Breshears, D.D.; Davi, H.; Galbraith, D.; Ruthrof, K.X.; Wunder, J.; Adams, H.D.; Bloemen, J.; Cailleret, M.; Cobb, R.; Gessler, A.; Grams, T.E.E.; Jansen, S.; ... O'Brien, M., 2018: Research frontiers for improving our understanding of drought-induced tree and forest mortality. New Phytologist, 218, 1: 15-28. doi: 10.1111/nph.15048
Lehmann, M.M.; Goldsmith, G.T.; Schmid, L.; Gessler, A.; Saurer, M.; Siegwolf, R.T.W., 2018: The effect of 18O-labelled water vapour on the oxygen isotope ratio of water and assimilates in plants at high humidity. New Phytologist, 217, 1: 105-116. doi: 10.1111/nph.14788
Milcu, A.; Puga-Freitas, R.; Ellison, A.M.; Blouin, M.; Scheu, S.; Freschet, G.T.; Rose, L.; Barot, S.; Cesarz, S.; Eisenhauer, N.; Girin, T.; Assandri, D.; Bonkowski, M.; Buchmann, N.; Butenschoen, O.; Devidal, S.; Gleixner, G.; Gessler, A.; Gigon, A.; ... Roy, J., 2018: Genotypic variability enhances the reproducibility of an ecological study. Nature Ecology & Evolution, 2, 2: 279-287. doi: 10.1038/s41559-017-0434-x
Kayler, Z.E.; Badrian, M.; Frackowski, A.; Rieckh, H.; Nitzsche, K.N.; Kalettka, T.; Merz, C.; Gessler, A., 2018: Ephemeral kettle hole water and sediment temporal and spatial dynamics within an agricultural catchment. Ecohydrology, 11, 2: e1929 (11 pp.). doi: 10.1002/eco.1929
Zhou, Y.; Zhang, B.; Stuart-Williams, H.; Grice, K.; Hocart, C.H.; Gessler, A.; Kayler, Z.E.; Farquhar, G.D., 2018: On the contributions of photorespiration and compartmentation to the contrasting intramolecular 2H profiles of C3 and C4 plant sugars. Phytochemistry, 145: 197-206. doi: 10.1016/j.phytochem.2017.11.004
Guderle, M.; Bachmann, D.; Milcu, A.; Gockele, A.; Bechmann, M.; Fischer, C.; Roscher, C.; Landais, D.; Ravel, O.; Devidal, S.; Roy, J.; Gessler, A.; Buchmann, N.; Weigelt, A.; Hildebrandt, A., 2018: Dynamic niche partitioning in root water uptake facilitates efficient water use in more diverse grassland plant communities. Functional Ecology, 32: 214-227. doi: 10.1111/1365-2435.12948
Oram, N.J.; Ravenek, J.M.; Barry, K.E.; Weigelt, A.; Chen, H.; Gessler, A.; Gockele, A.; De Kroon, H.; Van der Paauw, J.W.; Scherer-Lorenzen, M.; Smit-Tiekstra, A.; Van Ruijven, J.; Mommer, L., 2018: Below-ground complementarity effects in a grassland biodiversity experiment are related to deep-rooting species. Journal of Ecology, 106, 1: 265-277. doi: 10.1111/1365-2745.12877