Prof. Dr. Arthur Gessler

Function

Groupleader

Forest Dynamics

Ecosystem Ecology

Contact

arthur.gessler(at)wslto make life hard for spam bots.ch

+41 44 739 28 18+41 44 739 28 18

Swiss Federal Research Institute WSL
Zürcherstrasse 111
8903 Birmensdorf

Site

Birmensdorf Bi HL D 26

Understanding the processes that drive and regulate forest growth, biogeochemical cycles, biotic interactions and biodiversity-ecosystem functioning at different scales is of central importance to our work. Only with this understanding we can assess and predict shifts in the function of ecosystems and landscapes subjected to fundamental changes in the prevailing environmental conditions (i.e. climate and land use).

EDUCATION/TRAINING

Institution and Location

Degree

Year(s)

Field of Study

University of Freiburg

Diplom

Dr. rer. nat

PD (habil)

1994

1998

2004

Biology

Tree Physiology

POSITIONS: Employment /Experience

1994-1999	Postgraduate student/research assistant at the University of Freiburg (Institute of Forest Botany and Tree Physiology), Germany
1999-2002	Postdoctoral Fellow and Group leader at the University of Freiburg (Institute of Forest Botany and Tree Physiology), Germany
2002-2005	Research fellow of the Deutsche Forschungsgemeinschaft at the University of Freiburg, Germany
2002-2003	Visiting Fellow at the at the School of Forest and Ecosystem Science of the University of Melbourne, Austrlia
2005	Senior Research Fellow at the School of Forest and Ecosystem Science of the University of Melbourne, Australia
2005-2006	Visiting Fellow at the Research School of Biological Sciences at the Australian National University, Canberra, Australia
2006	Research Fellow at the Institut National de la Recherche Agronomique in Nancy/Champenoux, France
2006-2009	Head of the Core Facility Metabolomics at the Centre for Biosystem Analysis (ZBSA) of the University of Freiburg, Germany
2009-2014	Head of the Institute for Landscape Biogeochemistry at the Leibniz Centre for Agricultural Landscape Research (ZALF) and Professor for Landscape Biogeochemistry at the Humboldt University at Berlin
Since 2014	Research Program and Group Leader at the Swiss Federal Institute for Forest, Snow and Landscape Research WSL

Five selected Publications:

(a full publication list can be found at: www.arthur-gessler.de)

Hommel R, Siegwolf R., Saurer M, Farquhar GD, Kayler Z, Ferrio JP, Gessler A. 2014. Drought response of mesophyll conductance in forest understory species - Impacts on water use efficiency and interactions with leaf water movement. Physiologia Plantarum online.

Gessler A, Brandes E, Keitel C, Boda S, Kayler ZE, Granier A, Barbour M, Farquhar GD, Treydte K. 2013. The oxygen isotope enrichment of leaf-exported assimilates - does it always reflect lamina leaf water enrichment? New Phytologist 200: 144-157.

Offermann C, Ferrio JP, Holst J, Grote R, Siegwolf R, Kayler Z, Gessler A. 2011. The long way down – Are carbon and oxygen isotope signals in the tree ring uncoupled from canopy physiological processes? Tree Physiology 31: 1088-1102.

Wingate L, Ogée J, Burlett R, Bosc A, Devaux M, Grace J, Loustau D, Gessler A. 2010 Photosynthetic carbon isotope discrimination and its relationship to the carbon isotope signals of stem, soil and ecosystem respiration. New Phytologist, 188: 576–589.

Gessler A, Tcherkez G, Karyanto O, Keitel C, Ferrio JP, Ghashghaie J, Farquhar GD. 2009. On the metabolic origin of the carbon isotope composition of CO2 evolved from darkened light-acclimated leaves in Ricinus communis. New Phytologist 181: 374–386

FURTHER INFORMATION

Projects

Nanoparticle Trafficking in Trees

Our project, which proposes a novel approach (i.e., the use of virus-like particles), is key for the fundamental biological understanding of the transport and fate of nanoparticles in forest trees. Possible immediate applications include the development of new solutions for the nano-enabled foliar-a

SwissPhenocam: country-scale automated phenology tracking from imagery

The objective of the SwissPhenocam project is to develop and implement an automated phenology monitoring tool that will deliver added-value climate services regarding plant phenological responses to ongoing climate change and the carbon and water cycles.

INSIghtForest: IN SItu tracking of water fluxes in Forest ecosystems

INSIghtForest will accompany the Cost Action WATSON "WATer isotopeS in the critical zONeproposes" by establishing a unique data set of high frequency in-situ measured water isotopes located in a long-term irrigation experiment Pfynwald in the naturally dry valley of Valais, Switzerland.

FORWARDS: European Observatory to assess the vulnerability of forests towards climate change

FORWARDS aims to develop, test, and implement a European Observatory that will supply timely and detailed information on European forests' vulnerability to climate change impacts, and provide knowledge to guide climate smart forestry

VPDrought: A novel approach to disentangle atmospheric and soil drought

By deciphering the single vs. combined VPD and soil moisture effects, we will be able to improve global predictions. We aim to apply a scale spanning approach to disentangle the processes affected by atmospheric (i.e., VPD) and soil droughts from the tissue to the tree and the ecosystem level.

High-resolution climate reconstruction

Tree-ring d13C variations are a valuable archive of climatic information. A novel laser-ablation isotope-ratio mass-spectrometer enables to study variations within a single tree ring. We therefore plan to determine the occurrence of dry and wet periods of the past with unprecedented resolution.

Nanoplastic uptake and transport in trees

In this project we assess the uptake and transport of nanoplastics in trees by using polystyrene nanoparticles doped with Palladium and detection of these particles with ICP-MS.

TreeWater - Disentangling the isotopic signal transfer from source water to tree rings

TreeWater aims to improve our understanding of whether and how information on water uptake dynamics can be retrieved from the oxygen and hydrogen (i.e. water) isotopes in tree rings.

ProtoAIM - Enhanced Plot Design for Advanced Inventorying and Monitoring

We will enhance the design of the Swiss NFI plots to accomodate an augmented series of measurements, sampling and analysis needed to respond to pressing research question on status and change of the Swiss forest.

EMERGE - Extreme droughts in mountain regions

EMERGE will investigate the impacts of historic megadroughts on water fluxes and ecosystems in mountain regions, and use this knowledge to develop stress-test scenarios for a possible future megadrought in the Swiss Alps.

ICOS-2: Integrated Carbon Observation System in Switzerland, Phase 2017-2021

Die Forschungsstation Seehornwald Davos wurde in den 80er-Jahren von der WSL initiiert und ist damit eine der ältesten permanent betriebenen Wald-Vegetations-Forschungsstationen in der Schweiz.

PhenoRangers

"PhenoRangers" aims to establish interactions between current research on the impact of climate change on the forest and the public, using phenology as the main tool.

Cold stress mighgt limit carbon gain also in a warming climate

Photosynthesis of forest ecosystems can be reduced in spring most likely due to cold temperatures. Such cold-related processes are, however, not captured in mechanistic models and we thus aim to assess the mechanisms and frequencies of such depressions and include them into models.

N-DEPEND - Is there a "Nitrogen Deposition Penalty" for Forests under Drought?

This project intends to test the "N-penalty" hypothesis for the Swiss forests. By statistical modeling and quasi-experimental analyses based on N deposition estimates, drought indices and NFI data, we assess interacting effects of N deposition and drought on forest health and productivity.

How will changes in the phenology of species affect the biodiversity of lakes and their surrounding watersheds?

As part of the Blue-Green Biodiversity Research Initiative (Eawag-WSL funded by ETH), we study differences in the effect of global environmental change on the phenology of primary production in lakes and their surrounding watersheds using remote sensing techniques.

Phenological synchrony between soil microbes, nutrient availability, trees leaf-out and moths

The synchronization between supply and demand of resources in temperate forests is vital to ensure the optimal and sustainable functioning of these ecosystems. This project aims to understand how global warming is disrupting interactions between above- and below-ground organisms.

TreeNet - The biological drought and growth indicator network

TreeNet ist ein internationales Beobachtungs- und Forschungsnetzwerk, in dem Punktdendrometer automatisch die täglichen Stammradiusschwankungen von Bäumen erfassen. Der kontinuierliche Fluss von Daten liefert Echtzeitinformationen über die Wasserverhältnisse im Baum und das radial Stammwachstum

Drought & beech: Effects of the 2018 summer drought on beech on the northern side of the Alps

In this project, we investigate causes for the impacts of the extreme summer drought 2018 on the vitality of beech trees in different regions of the Swiss Plateau and Jura.

UAV-based monitoring of physiological tree responses

In this project, we investigate the potential of spectral proxies, obtained from unmanned aerial vehicles (UAV) high-resolution multispectral and thermal imaging, to detect trees pre-visual drought stress responses.

Integration of biodiversity conservation and forest management

The publication "How to balance biodiversity conservation and forest management - a tour across Europe" written by more than 70 scientific and professional experts from 50 Institutions and 20 different countries explores how to best integrate biodiversity conservation in forest management

eLTER Switzerland

The Long-Term Ecologiocal Research in Europe (LTER-Europe) capitalizes on research infrastructures such as the in-situ network of sites and information technology. Thousands of research projects have been carried out taking advantage of this infrastructure.

Acclimation and environmental memory

Which are the main mechanisms conveying adaptation on the organ and whole tree level, how fast does acclimation occur and how long is an acclimation potential sustained?

PFF2020

Our main objective is the installation of a long-term Plant Physiological Facility for online determination of gas exchange and isotope fractionations at WSL in the 2020s.

TreeCarbo: From assimilates towards tree-rings - Triple isotope analysis of carbohydrates

The project aims to provide novel mechanistic ways to reconstruct functional responses of trees to climatic changes in high temporal and spatial resolution by improving and combining fractionation models for carbon, oxygen, and hydrogen isotopes.

Give and take: how much water does soil retain for trees?

Establishing an inventory of soil water availability to trees in Swiss forest soils. This is done by means of model-based analysis of the water balances at 16 long-term monitoring sites in Switzerland, representing various geographical locations, soil and vegetation types.

FORClimateS

The project aims to aggregate and synthesize existing information on different spatial and temporal scales to provide decision-makers with relevant and robust information on short- and long-term risks for forests and forest functions and on adaptation strategies under different climate futures

Isodrought

We want to explore a stable isotope tree-ring approach for analyzing physiological drought responses of trees. The results are expected to provide a novel diagnostic tool for understanding causes of tree decline.

Photoperiod and ciracian clocks - effects on adaptation and acclimation

Do evolutionary constraints on photoperiod and circadian clocks hinder adaptation and acclimation of plants to climate change? With this project, we will provide the mechanistic basis and a conceptual framework to understand how climatic and daylight/photoperiod cues jointly affects tree functioning.

Adaptation of trees to extreme climate events

Extreme climate events are expected to become more frequent with climate warming. We test genetic differentiation in resistance to late frost and drought in silver fir populations planted in the 1980s in Swizterland and abroad.

Carbon storage and ungulate browsing

The joint effects of drought tolerance and herbivory is determined by analysing the extent to which water use efficiency and C storage of Abies alba saplings are influenced by genetic factors and ungulate browsing.

Forests under stress

In this project we will assess the physiological processes by which trees adjust and interact among each other under a changing climate, determine the consequences of these processes on forest responses to climatic stresses and improve our understanding of these effects on forests functioning at a large comprehensive scale.

Sumforest - ForRISK

Risk resilient forest management - Adapting forest management regimes, including risk assessment related to potential climate change impacts.

Drought effects on reproductive phenology and the underlying physiological mechanisms in pine trees

We use a long-term precipitation manipulation experiment in mature Pinus sylvestris forests and a natural precipitation gradient from 840 mm to 290 mm/year with Pinus sylvestris var. mongolica, to study the "Drought effects on reproductive phenology and the physiological mechanisms of pine trees".

Tea bag decomposition study

Decomposition of plant litter is a key process for the transfer of carbon and nutrients in ecosystems. Carbon contained in the decaying biomass is released to the atmosphere as respired CO2, and may contribute to global warming. Litterbag studies have been used to improve our knowledge of the drivers of litter decomposition, but they lack comparability because litter quality is plant species-specific. The use of commercial tea bags as a standard substrate was suggested in order to harmonize studies, where green tea and rooibos represent more labile and more recalcitrant C compounds as surrogates of local litter.

Carbon and nutrient dynamics of Scots pine

In the CaNuPine project, we study the effects of drought and nutrient availability on the carbon dynamics within Pine (Pinus sylvestris) trees. This will contribute to the controversial debate whether drought may or may not cause acute growth decline and mortality via carbon starvation.

Landscape-scale biodiversity

Biological diversity has a huge potential to preserve and support agricultural ecosystem services. This project analyses the impact of agricultural and environmental policies on biodiversity and ecosystem services of agricultural production systems.

Integrated Carbon Observation System (ICOS)

Integrated Carbon Observation System (ICOS) is a European research infrastructure to quantify and understand the greenhouse gas balance of the European continent and of adjacent regions.

Irrigation Experiment Pfynwald

Drought-induced forest decline will gain in importance as the frequency and severity of drought events are expected to increase in the context of climate change. To understand how chronic drought affects tree growth, we study mature Scots pine in an irrigation experiment in an inner-Alpine dry valley since 2003.

Crown condition assessment

It is important to have good information on the condition of the trees in the plots. Therefore scientists determine the relationships between crown condition and a number of environmental parameters.

TreeNet

TreeNet is a biological drought and growth indicator network of forest ecosystems. It provides information about drought responses of trees all over Switzerland and their effects on the carbon balance of forests. TreeNet links the research of the eddy flux super sites Davos and Lägeren to the forest next to your home.

Show all

Publications WSL

Scientific publication article peer reviewed

Zhang, Y.; Yang, Y.; Saurer, M.; Schaub, M.; Gessler, A.; Lehmann, M.M.; Rigling, A.; Walser, M.; Stierli, B.; Hajjar, N.; Christen, D.; Li, M., 2023: Sugar infusion into trees: a novel method to study tree carbon relations and its regulations. Frontiers in Plant Science, 14. doi: 10.3389/fpls.2023.1142595

Beloiu, M.; Heinzmann, L.; Rehush, N.; Gessler, A.; Griess, V.C., 2023: Individual tree-crown detection and species identification in heterogeneous forests using aerial RGB imagery and deep learning. Remote Sensing, 15, 5: 1463 (17 pp.). doi: 10.3390/rs15051463

Baumgarten, F.; Gessler, A.; Vitasse, Y., 2023: No risk—no fun: penalty and recovery from spring frost damage in deciduous temperate trees. Functional Ecology, 37: 648-663. doi: 10.1111/1365-2435.14243

Zweifel, R.; Pappas, C.; Peters, R.L.; Babst, F.; Balanzategui, D.; Basler, D.; Bastos, A.; Beloiu, M.; Buchmann, N.; Bose, A.K.; Braun, S.; Damm, A.; D'Odorico, P.; Eitel, J.U.H.; Etzold, S.; Fonti, P.; Freund, E.R.; Gessler, A.; Haeni, M.; ... Sterck, F., 2023: Networking the forest infrastructure towards near real-time monitoring - a white paper. Science of the Total Environment, 872: 162167 (11 pp.). doi: 10.1016/j.scitotenv.2023.162167

Saurer, M.; Sahlstedt, E.; Rinne-Garmston, K.T.; Lehmann, M.M.; Oettli, M.; Gessler, A.; Treydte, K., 2023: Progress in high-resolution isotope-ratio analysis of tree rings using laser ablation. Tree Physiology, doi: 10.1093/treephys/tpac141

Show all

Further scientific publications

Waldner, P.; Hobi, M.; Stillhard, J.; Brang, P.; Hug, C.; Thimonier, A.; Schmitt, M.; Walser, M.; Köchli, R.; Zürcher, A.; Christen, D.; Hajjar, N.; Schaub, M.; Sutter, F.; Häni, M.; Meusburger, K.; Gessler, A.; Nussbaumer, A.; Hirsiger, T.; Zhu, J., 2023: Forschung im Waldreservat am Bettlachstock. Mitteilungen der Naturforschenden Gesellschaft des Kantons Solothurn, 161-179. doi: 10.5169/seals-1007786

Zweifel, R.; Basler, D.; Braun, S.; Buchmann, N.; Conedera, M.; Etzold, S.; Eugster, W.; Floriancic, M.; Fonti, P.; Gessler, A.; Haeni, M.; Hoch, G.; Hummel, D.; Kahmen, A.; Koechli, R.; Maeder, M.; Nievergelt, D.; Peter, M.; Peters, R.; ... Wilhelm, M., 2022: TreeNet. Technischer Bericht 2022. 76 p.

Gessler, A.; Ferrio, J.P., 2022: Postphotosynthetic fractionation in leaves, phloem and stem. In: Siegwolf, R.T.W.; Brooks, R.J.; Roden, J.; Saurer, M. (eds), 2022: Stable isotopes in tree rings. Inferring physiological, climatic and environmental responses. Cham, Springer. 381-396. doi: 10.1007/978-3-030-92698-4_13

Rathgeber, C.B.K.; Pérez-de-Lis, G.; Fernández-de-Uña, L.; Fonti, P.; Rossi, S.; Treydte, K.; Gessler, A.; Deslauriers, A.; Fonti, M.V.; Ponton, S., 2022: Anatomical, developmental and physiological bases of tree-ring formation in relation to environmental factors. In: Siegwolf, R.T.W.; Brooks, R.J.; Roden, J.; Saurer, M. (eds), 2022: Stable isotopes in tree rings. Inferring physiological, climatic and environmental responses. Cham, Springer. 61-99. doi: 10.1007/978-3-030-92698-4_3

Resco de Dios, V.; Gessler, A., 2021: Sink and source co-limitation in the response of stored non-structural carbohydrates to an intense but short drought. Trees: Structure and Function, 35: 1751-1754. doi: 10.1007/s00468-021-02116-9

Show all

Magazine article and brochures

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.

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.

Show all