Swiss forests are exposed to changing environmental conditions. The consequences of air pollution and climate change on the forest are important questions which the Long-term Forest Ecosystem Research Programme LWF seeks to answer.

Available languages: German English French

COST Action FP0803 chaired by WSL soil scientist Ivano Brunner. Focusing on the four key areas: fine root turnover, mycorrhizal mycelia turnover, soil C stocks, and biogeochemical modelling, with the intention of linking the different research fields involved, evaluating the potential of new and innovative methodologies, and developing new process-based descriptions of belowground C dynamics within biogeochemical models.

Available languages: English

Nitrate concentrations in groundwater have increased, mainly due to intensive agriculture, and constrain its usage as drinking water in parts of Switzerland. Nitrate leaching from forests are, in comparison, generally small but may increase due increased nitrogen deposition and warm and dry periods. This project aims on exploring the possibilities and limitations for a better estimation of the risk of future nitrate leaching from forests.

Available languages: English

Der Klimawandel stellt eine zentrale Herausforderung des 21. Jahrhunderts dar. Auch auf den Wald könnte sich der Klimawandel einschneidend auswirken. Um diese Auswirkungen zu begrenzen und die Waldleistungen sicherzustellen, benötigen die Waldfachleute Grundlagenwissen und Entscheidungshilfen.

Available languages: German

The aim of the research project WaMos 2 is to assess the attitudes of the population towards forest and wood related topics. In doing so, the project revisits and builds upon work that was done in 1997. The results of WaMos 2 will serve as a basis for forest related policy, and the forest- and environment-related reporting of FOEN.

Available languages: German English French

Poplar "guinea pig": Are poplar clones, selected for their tolerance to boron and salt contamination also tolerant to metal contamination or drought stress? Californian (USA) poplar clones were selected for their tolerance to boron and salt contamination in the soil. Cuttings from such clones grown in contaminated and control soil in California have been put into soil with and without metal contamination at Birmensdorf (CH) to test their tolerance to metal contamination.

Available languages: German English French

In Zusammenarbeit mit der Schweizerischen Hochschule für Landwirtschaft SHL wurde ein Simulationsmodell entwickelt, welches unter verschiedenen Waldbehandlungsmethoden, Holzmarktbedingungen und unterschiedlichen Nutzungsgraden der Baumkompartimente für einen Zeitraum von 20 Jahren ermittelt.

Available languages: German

In Zusammenarbeit mit dem Zentrum für Unternehmenswissenschaften der ETH (BWI) wurde untersucht, inwieweit das in der Industrie etablierte Supply Chain Operations Reference (SCOR)-Modell zur Beschreibung und Standardisierung der zweiten Produktionsstufe Holz (technische Holzproduktion) eingesetzt werden kann.

Available languages: German

Recent Scots pine mortality in forests of the upper Rhone valley have been suggested to be caused by climate change. In an ongoing PhD study, effects of different climate parameters and interspecific competition on the regeneration of both Scots pine (Pinus sylvestris) and black pine (Pinus nigra) are tested.

Available languages: German English French

Entwicklung eines Modells zur Beurteilung der Nährstoffentzugsrisiken infolge intensiver Holznutzung. In enger Zusammenarbeit mit der WSL-Bodenkunde wurde ein Nährstoffbilanzierungsmodell entwickelt, welches für konkrete Waldstandorte die Nachhaltigkeit von verschiedenen Holzerntemassnahmen beschreibt.

Available languages: German

IFIS UNO bietet eine web-basierte Plattform, welche die unternehmensübergreifende Kommunikation, Koordination und Kooperation unter den Akteuren in der Holzkette ermöglicht und in ihren Aktivitäten unterstützt. Die Plattform wurde in enger Zusammenarbeit mit der Forstpraxis und Softwareherstellern entwickelt (AAREHOLZ AG, ZürichHolz AG, Holzzentrale Nordwestschweiz AG, RAMCO-Systems Ltd. Basel).

Available languages: German

Falls durch den Klimawandel die Wichtigkeit der Stürme zu- und die Widerstandskraft der Wirtsbäume abnehmen, können Borkenkäfer limitierend wirken. Entlang von Höhengradienten in Fichtenwäldern werden die Populationen von Borkenkäfern und natürlichen Feinden sowie die Vitalität der Fichten erhoben.

Available languages: German

Der Klimawandel könnte die Widerstandskraft von Bäumen gegen Insektenbefall schmälern. Im Rahmen zweier Projekte werden im Wallis, im benachbarten Aostatal (IT) und im Churer Rheintal entlang von Höhengradienten die Populationsgrössen und das Befallspotential von rindenbrütenden Insekten abgeschätzt.

Available languages: German

In this project we want to detect and describe factors that govern the evolution of virulence in the host–parasite interaction between Cryphonectria parasitica and Cryphonectria hypovirus 1 (CHV1). C. parasitica is an introduced fungus and causes the serious tree disease called chestnut blight. It can be biologically controlled by CHV1.

Available languages: English

Die Klimerwärmung dürfte den Wald auf vielen Standorten unter Stress setzen. Wir untersuchen, ob die genetische Variation der Waldbäume es ihnen erlaubt, sich an den Klimawandel anzupassen. Wir fokussieren dabei auf die drei häufigsten Baumarten in Schweizer Wäldern, die Fichte, die Tanne und die Buche.

Available languages: German English

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.

Available languages: English

Trees respond to its environment in various ways. Some of the responses to e.g. the microclimate can be detected with ecophysiological methods like dendrometers, sap flow sensors, ultrasonic acoustic emission detectors and some others. The project 'trees' led by the Institute for Computer Music and Sound Technology (ICST) links the ecophysiological records to an audible output. We let the trees sing in the way that we turn physiological responses into music. The main focus is on ultrasonic acoustic emisions from tree stems, recognized as a sound with a physiological origin.

Available languages: English

This project involves a Free Air CO2 Enrichment (FACE) and soil warming experiment located in a natural treeline environment near Davos, Switzerland (Stillberg, 2200 m a.s.l.)

Available languages: German English French

The goal of the project is to measure the effect of an elevated CO2 concentration onto the availability of nutrients in the soil, especially nitrogen. Are nutirents becoming more and more a limiting factor as CO2 availability to trees increases?

Available languages: German English French

This framework project contains research done on the site Erlenhöhe at Alptal (canton Schwyz, central Switzerland). It consists mainly of a nitrogen (N) addition experiment in which the effetcs of N deposition on a subalpine forest ecosystem are studied.

Available languages: German English French

This is an interdisciplenary project, financed by the SNF Sinergia program, to investigate niche evolution. We seek to understand how niche evolution will contribute to patterns of biodiversity under altered climates.

Available languages: English

A recent study on Scots pine and pubescent oak in Valais indicated that both species might not have the potential for long-term establishment and performance under an expected drier climate. We want to find out if non-endemic species can contribute to the tree-species portfolio for a drier future climate.

Available languages: German English

Der eingeschleppte Kastanienrindenkrebs gefährdet die Edelkastanienbestände auf der Alpennordseite. Um diese Bestände zu erhalten, wird im Rahmen dieses Projektes der Kastanienrindenkrebs auf der Alpennordseite mit hypovirulenten Pilzstämmen bekämpft

Available languages: German

This project is supported by the Swiss National Science Foundation. It belongs to the group of projects aiming to improve the TreeMig forest landscape model for climate change impact assessments on regional to continental scales.

Available languages: English

Totholz ist Lebensgrundlage für rund einen Viertel aller Organismen im Wald. Die künftig wahrscheinliche Intensivierung der Holzwirtschaft wird viele holzbewohnende Insekten noch stärker gefährden. In diesem Projekt werden in Waldreservaten die Entstehung und der Abbau von Totholz quantifiziert, die Abhängigkeit von Insekten von Totholz untersucht und Mindestwerte für das Totholzangebot abgeleitet.

Available languages: German

In this project, we aim to investigate 1) to what extent diversity of mycorrhizal fungi is diminished by forest fire, and 2) whether this has consequences for performance of Pinus sylvestris seedlings.

Available languages: German English

A landscape scale forest population dynamics model is extended with ecophysiology, and particularly the mechanisms of drought effects on trees.

Available languages: English

The project investigates the effects of a wood ash application on the nutrient status and further soil chemical properties of an acid forest soil in Switzerland.

Available languages: English

The project investigates the effects of litter removal on the carbon stock and the nutrient dynamic of various forest soils in Switzerland.

Available languages: English

The aim of this project is to obtain an overview of contents, effective mobility and potential ecotoxicity of heavy metals in Swiss forest soils.

Available languages: German English

This is part of the project cluster “From Cell to Tree”. The phytostabilisation of metal contaminated soils by afforestation is investigated in a large lysimeter experiment. In this subproject, the chemical properties of the soil and how they affect roots and microorganism are studied.

Available languages: English

Acidification of forest soils can lead to high concentrations of phytotoxic aluminium in the soil solution. In this project the hypothesis is tested that the aluminium tolerance of Norway spruce is increased by root exudation of organic acid anions that form stable complexes with the metal.

Available languages: English

Mobilization of aluminium in acidic soils is regarded as a health threat to many European forests. In this project, we are developing biomarkers indicating Al exposure and effects by capitalizing on genome resources recently established for forest trees.

Available languages: English

The present distribution of European forest trees is largely the result of colonization from refugia where the species survived the last glaciation. In this project, we combine genetic and paleoecological data for studying the history of the Bödmerenwald-spruce, a geographically limited Picea population with outstanding high genetic diversity.

Available languages: English

The co-operation with the Carpathian Biosphere Reserve and other partners in Ukraine mainly focus on research in virgin forests. Comparative studies on the structure, dynamics and biodiversity of virgin and managed forests shall contribute to optimizing management strategies for the conservation of forest biodiversity and for a sustainable, close-to-nature use of the forest resources.

Available languages: English

In a joint research project with Ukrainian partners we compare the structures of the virgin beech forest Uholka in Ukraine with those of the Sihlwald near Zurich and assess the development process of Sihlwald from commercial forest back to "virgin forest".

Available languages: English

Soil compaction caused by passage of logging machinery reduces the soil air capacity. Prolonged compaction of forest soils might enhance greenhouse gas-producing microbial activities and induce a change in the soil microbial community and favour organisms capable of tolerating anoxic conditions.

Available languages: English

Mit zunehmendem Maschineneinsatz bei forstbetrieblichen Massnahmen und die dadurch entstehenden negativen Auswirkungen auf die Funktionen von Waldböden stellt sich die Frage nach den Möglichkeiten und Grenzen von biologischen Regenerationsmassnahmen, um die Standortsnachhaltigkeit zu fördern bzw. zu erhalten.

Available languages: German

WSL contribution to the project 'Spatial extremes and environmental sustainability: Statistical methods and applications in geophysics and the environment' of the 'Competence Centre for Enviromnent and Sustainability' of the ETH Domain (CCES EXTREMES)

Available languages: English

Roots play an important role as storage organs. Carbohydrate supply to roots is a key process linking environmental effects on shoot and changes in the growth and function of roots. In this study we use poplar (Populus tremula) as a model tree plant. Above ground stress are applied to poplar in order to modulate the carbohydrate metabolism in the roots.

Available languages: English

Within this study critical levels of cadmium, mercury and lead in the soil matrix, soil solution, fungi, earthworms and their food sources will be determined and ecotoxicological effects on the soil microbial communities will be evaluated.

Available languages: English

The chemistry of soil solution and the soil water availability for plants have been monitored since 1997 in seven forest plots in Switzerland. This project, linked to the Swiss Long-term Forest Ecosystem Research project (LWF), aims to assess the soil response to atmospheric pollution (acidifying substances and nitrogen) and to climate change.

Available languages: English

Historical photographs document that the upper treeline of the Ural mountains has moved up 60 to 80 m during the last century. We assess how the expansion of forests into tundra affects soil organic matter dynamics in the pristine Southern, Northern and Polar Ural.

Available languages: English

Concentrations of atmospheric CO2 and temperatures will strongly increase during the next century. We are investigating how these climatic changes will affect plant growth, biodiversity, and the cycling of carbon and nutrients in temperature sensitive ecosystems at the alpine treeline.

Available languages: German English

The cycling of carbon and nitrogen are closely linked and thus, the increasing deposition of nitrogen very likely affects soil organic matter dynamics. We are adding 13C and 15N labeled litter from beech to soils and investigate how experimentally increased N inputs influence the fate of litter-derived C and N.

Available languages: English

In a unique CO2 enrichment study experiment – the Swiss Canopy Project - led by the Institute of Botany, University of Basel (Prof. Körner) we are measuring DOM fluxes. A 100 year-old mixed broadleaf forest is exposed to elevated CO2 with the help of a crane. The added CO2 is depleted in 13C as compared to normal air, allowing to trace assimilated CO2 through the tree and soil system and to gain insight into soil C cycling.

Available languages: English

Ziel des vorliegenden Projektes ist es, die vermuteten Zusammenhänge zwischen Bodenversauerung und Wurzelschädigung nachzuweisen. Dazu soll die ‘Vitalität’ der Feinwurzeln von Buchen an denjenigen Waldstandorten erfasst werden, welche gemäss der Indikatoren für Aluminium-Stress die kritischsten Werte im Schweizer Mittelland aufweisen.

Available languages: German

The proposed project has the aim to investigate fluxes, pools, and turnover of C within the fine root systems of individual trees over time and space. The various forms of labelled C, from fine roots respired CO2 as well as non-structural and structural carbohydrates within the fine roots, recorded shortly before and after the C pulse will give important information about the contribution of individual trees to the soil C and its dynamics.

Available languages: English

This project has the aim to investigate whether tree roots, similarly to many crop plants, exude organic acids at enhanced concentrations of Al or heavy metals.

Available languages: English

The aim of this project is to investigate whether roots of European chestnut (Castanea sativa) show physiological reactions to soil acidification processes.

Available languages: English

In der Langfristigen Waldökosystem-Forschung LWF wird die Entwicklung von16 unterschiedlichen Waldökosystemen in der Schweiz mit spezieller Berücksichtigung der anthropogenen Einwirkungen untersucht. Der Boden bildet dabei als wichtige Komponente jedes Waldökosystems ein zentrales Untersuchungsobjekt.

Available languages: German

PO3PLAR is a bio-indicator initiative to contribute to an ozone risk assessment based on the Level II network.

Available languages: English

Cette recherche, située dans le cadre du projet européen COST E39, vise à mieux connaître la contribution des forêts à la santé et au confort de la population en Suisse en quantifiant les différences existant entre le climat sous couvert forestier et le climat hors couvert forestier. Il analysera les mesures du réseau LWF.

Available languages: French

In this study we analyse the effect of drought stress on tree growth of scots pine and pubescent oak to rate the potential of the two species to survive in an expected hotter and therefore drier environment.

Available languages: German English

Microclimate, fluxes of CO2 and other gases by eddy covariance and tree physiological measurements under field conditions have been recorded at the Seehornwald Davos research site for two decades. Currently, we are analyzing the unique data sets in terms of tree physiological responses to climate change over the recent decades.

Available languages: German English

In Valais, Scots pine (Pinus sylvestris) and pubescent oak (Quercus pubescent) grow at least temporally at the edge of their physiological capabilites. We investigate the (potential) adaptation of these and co-occurring tree species to climate change and search for limits they might reach with increasing temperatures and droughts.

Available languages: German English

Cost-effective management of protection forests means reducing the risk caused by natural hazards to an acceptable level, with the least input possible. The protection forest model enables a comparative evaluation of different management strategies.

Available languages: German English

Within the frame work of the UNECE Convention on Long-Range Transboundary Air Pollution, the WSL investigates the physiological and growth effects on trees by means of ozone flux modeling in order to assess the risk of ozone on forest ecosytems.

Available languages: English

Querco, in the sense of "quid Quercus, quo vadis?" To study the reaction of 3 local species of oak (each species with 4 provenances) to drought, increasing air temperature and a combination of the two will be the focus of this experiment.

Available languages: German English French

Am 26.12.1999 fegte der Orkan "Lothar" über den Rorwald (Kanton Obwalden) hinweg. Es entstanden grosse Windwurfflächen, auf denen sich der Buchdrucker schnell zu vermehren begann. Die WSL untersucht im neu gegründeten Waldreservat Rorwald, wie sich der Wald ohne forstliche Eingriffe nach dem Sturm entwickelt.

Available languages: German

Aktuelle und historische Waldschutzdaten bilden die Grundlage für die laufende Beurteilung der Waldschutz-Situation sowie für Prognosen und Risikoabschätzungen von abiotischen und biotischen Einflüssen auf den Wald. Die Daten werden mit verschiedenen Methoden beschafft und laufend ausgewertet.

Available languages: German

Insekten prägen massgebend die Dynamik unserer Waldökosysteme, z.B. durch Massenvermehrungen. Informationen zur Verbreitung, Biologie und Epidemiologie der Waldinsekten dienen dazu, angepasste Massnahmen der Überwachung und Bekämpfung zu erarbeiten. Praxis und Behörden stützen sich bei ihrem Risikomanagement auf unsere wissenschaftliche Beratung und Diagnose.

Available languages: German

Wichtige Informationen zur Beurteilung der Waldgesundheit stammen aus der Beratung, bei welcher mittels differenzialdiagnostischen Methoden die Ursachen von Baumkrankheiten analysiert werden. Die Kunden agieren als externe Mitarbeiter und erhalten als Gegenleistung die Diagnose inklusive einer Empfehlung für das geeignete weitere Vorgehen.

Available languages: German

Abiotische Einflüsse, Insekten, Krankheitserreger oder das Wild können die Waldfunktionen beeinträchtigen, Ertragseinbussen zur Folge haben oder extreme Veränderungen an den Bäumen verursachen. Derartige Forstschutzereignisse werden schweizweit erfasst und dokumentiert. Interessierte Kreise und Medien werden mit aktuellen Rundschreiben und dem jährlichen Forstschutz-Überblick informiert.

Available languages: German

The public accounts of swiss forests as protective shelter against natural hazards amounts to milliards of swiss francs per annum. What is actually the mechanical resistance of forest stands against natural hazards?

Available languages: German English

Wissenschafter analysieren vorhandene Befahrungsschäden in Abhängigkeit vom Standort und von unterschiedlichen Mechanisierungsgraden. Sie beurteilen die Möglichkeiten zur Schätzung der Befahrungsempfindlichkeit und erarbeiten Entscheidungshilfen für die schonende Befahrung von Waldböden sowie für die Feinerschliessung.

Available languages: German French

Die Zusammenhänge zwischen Wasserhaushaltsgrössen im Boden und der Durchwurzelungssituation sind noch ungenügend bekannt. Insbesondere in Regionen mit durch Stauwasser geprägten Böden könnte die Wurzeldichte einen Einfluss auf die Infiltration aufweisen und die Baumartenwahl somit ein Instrument im Hochwasserschutz sein.

Available languages: German

How fast do plant species recolonise the burned soils after forest fires, and which factors facilitate or inhibit tree regeneration? In this project we monitor re-vegetation with respect to vascular plants and mosses along an elevational gradient ranging from 900 to 2100 m asl. Results will be used to derive management strategies in relation to forest fires.

Available languages: German English

Auf der Aufforstungsversuchsfläche Stillberg untersuchen Forschende seit über 30 Jahren die Wechselwirkungen zwischen Schnee, Lawinen und Bäumen an der alpinen Waldgrenze. Bereits ist eine einmalige Datengrundlage vorhanden, die zur Beantwortung von wissenschaftlichen und praktischen Fragen dient. Zurzeit laufen am Stillberg sechs Projekte.

Available languages: German French

Wie lange bieten durch Borkenkäfer verursachte Totholzbestände Schutz gegen Naturgefahren? Wie schnell nimmt die mechanische Stabilität der Stirzel (abgestorbene Bäume) ab? Brechen die Stirzel oberirdisch ab oder entwurzelt sich der ganze Stirzel bei entsprechender Belastung? Welche Pilzarten treten bei der Zersetzung des Holzes auf?

Available languages: German

Die Scherfestigkeit des Bodenmaterials spielt für die Rutschungsstabilität von Hängen eine zentrale Rolle. Forscher der WSL entwickelten einen neuen Ansatz, um den Vegetationseinfluss auf die Boden- und Hangstabilität zu quantifizieren. Sie ordnen den Vegetationseffekt dem Scherwinkel des Bodenmaterials zu.

Available languages: German

Mit dem Projekt "Monitoring Flankierende Massnahmen Umwelt" (MFM-U) untersucht die Schweiz die Umwelt-Auswirkungen des Landverkehrsabkommens mit der EU sowie die Umwelt-Auswirkungen der flankierenden Massnahmen. Im diesem Teilprojekt stehen die Auswirkungen auf den Wald im Vordergrund. Als Indikator dient der Elementgehalt von Fichtenadeln.

Available languages: German

Forest fires are common events in Ticino. Nevertheless they cannot be regarded as natural phenomena because they are mostly anthropogenically triggered. The aim of this project was to better understand human behaviour towards forest fire phenomena, linking the results to climate change and its impacts.

Available languages: English French

During the floods in August 2005 in Switzerland, many villages encounter problems not only because of a high water flow, but also because of large amounts of driftwood. Therefore the question of the origin and the formation of the driftwood arised.

Available languages: German English French

The potential of plants to migrate to habitats which are more favourable under changed conditions plays a key role in assessing the impacts of climate change on terrestrial ecosystems. A new, spatially explicit, physiologically mechanistic, and efficient forest succession model was developed in order to study the potential of trees to invade, migrate and get extinct under current and possibly changed future climate.

Forests of the Central Rocky Mountains are of value for nature conservation and biodiversity maintenance. Developing a spatially explicit forest succession model upon a sound physiological basis is important to assist management and to further science of these crucial forests.

Die Nutzung des Waldes in der Schweiz hat sich seit der 1950er Jahre grundlegend verändert. Viele traditionelle Waldnutzungen verschwanden. Sie sind oft kaum dokumentiert, obschon sie aus kulturhistorischer und ökologischer Sicht von grossem Interesse sind. Diese Veränderungen werden mit der Methodik von Oral History dokumentiert und analysiert.

Available languages: German

In many regions of the world, fires are a major driver of vegetation development. Understanding the various factors that are crucial for shaping the current fire regime requires a multi-faceted approach. In this project, the scientists analyze the past, present, and future fire regimes of a region that is likely to become more fire-prone in the future, the Canton of Valais.

Available languages: English

Only 150 years ago, Swiss forests were markedly affected by agro-forestal uses. In many places leaf litter was collected for different reasons. By experimental removing of the leaf litter, we examine the ecological consequences of this forest use and we evaluate it's potential as a new tool for nature conservation in forests.

Available languages: German English

Remote sensing is an indispensable tool for monitoring landscape. Aim of the project is to develop efficient methods, which are supposed to allow for the acquisition of reproducible, high-quality landscape informations from remote sensing data. These methods are applied in the National Forest Inventory and the Landscape Inventories.

Available languages: German English French Italian

Veränderte Ansprüche und technische Neuerungen verlangen laufend Anpassungen der Waldinventur-Verfahren. Mit diesem Projekt entwickeln Wissenschafter die dazu notwendigen Methoden und beraten in statistischen Fragen.

Available languages: German

Bei der Organisation und Durchführung von Waldinventuren muss ein konstanter Erfassungsstandard über lange Zeiträume sichergestellt sein. Es gilt, neue Daten unter Wahrung der Kontinuität in das Inventursystem zu integrieren und die Datenqualität zu gewährleisten.

Available languages: German

Das Ziel dieses Projektes ist es, Merkmale für die Quantifizierung der heutigen und zukünftigen Wald- und Landschaftswirkungen zu erarbeiten, Möglichkeiten für die Erfassung der gesellschaftlichen Ansprüche aufzuzeigen und Modelle für die Bewertung von Waldzuständen und deren Veränderungen zu entwickeln.

Available languages: German

Nach den grossen Stürmen Vivian (1990) und Lothar (1999) wurden Untersuchungen begonnen, um die langfristige Entwicklung der Insektenvielfalt auf geräumten und ungeräumten Sturmflächen zu verfolgen. Ein bzw. zwei Jahrzehnte nach den Stürmen werden wieder Felderhebungen durchgeführt.

Available languages: German

Many of the problems associated with sustainable forest management relate to questions and understanding at the ecosystem and landscape levels, as well as requiring long-term series of data. The overall objective of ENFORS is to develop the scientific base for, and initiate a European network of sites for forest ecosystem and landscape research.

Available languages: English

In long-term projects like Long-term Forest Ecosystem Research (LWF), collected data represent an important scientific asset/treasure. Thus, it is of primer importance to store this data in controlled and well documented structures.

Available languages: German English

Since 1985, the condition of forests in Switzerland has been monitored through the Sanasilva Inventory. 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.

Available languages: English

The knowledge of the defoliation effects on the physiological processes resulting in tree growth is still lacking. How are the responses of the photosynthetic activity and the coresponding available carbohydrates to defoliation? What are the effects on height, on diameter growth and in the wood anatomical characteristics of tree rings?

Available languages: English

In a changing environment, the analysis of how forest ecosystems may react under scenarios involving changing climatic conditions is of major importance. This project wants to evaluate the influence of expected climatic changes (precepitation and temperature regimes) on trees and the state of our forests.

Available languages: English

Im Wallis weisen die Waldföhren seit Jahrzehnten eine erhöhte Sterberate auf. Dafür wächst vermehrt die Flaumeiche. Wissenschafter der WSL haben die komplexen Ursachen des Waldföhrensterbens entschlüsselt.

Available languages: German

The assessment of the crown transparency of trees is a key component of long-term monitoring programmes of forest health. The aim of this project was to examine long-term needle retention of Pinus sylvestris. The data was related to growth information from the trees, and the data used in a modelling study of needle retention - growth - climate relationships.

Available languages: English

Welche Faktoren tragen bei Windwürfen massgeblich zu den Schäden bei? In welchen Fällen wäre das Ausmass der Schäden kleiner? Landesweite repräsentative Datenerhebungen zu Lothar-Sturmschäden und zu den betroffenen Waldbeständen sollen Antworten auf diese Fragen liefern.

Available languages: German

Meteorological factors and regional climate changes play an important part in the long-term forest ecosystem research (LWF). In order to document these climate changes and to understand the dynamics in the ecosystems, site-specific meteorological data is required.

Available languages: German English French

Ozone is the most important regional air pollutant that may impact forest vegetation in Europe. This project addressed an important ecological, scientific and political issue: Provide a synoptic view of descriptors of ozone concentration at 62 forest sites in south-western Europe and evaluate the factors associated to ozone concentration.

Available languages: English

Little information was available on the effects of ozone on the multitude of native forest plant species. Hence, the aim of this study was to examine long-term ozone concentrations in relation to the onset and development of visible foliar injury on several forest, shrub and herb species.

Available languages: English

Since two decades an increase of defoliation has been observed in forest trees. There are suggestions that the water budget is a critical factor affecting needle and leaf loss. A water budget model is used to investigate the relationships between water budget and defoliation.

Available languages: German English

The fine roots of forest trees are the actual interface between the soil solution and plants. What is the influence of environmental changes on the rooted area of forest trees and the condition of mycorrhizas?

Available languages: German English

Ground vegetation is a powerful bio-indicator of the environment. The project aims at discriminating the various factors which may influence the dynamics of ground vegetation. Emphasis is being given to the role of nitrogen.

Available languages: English French

Long-range transport of tropospheric ozone and its pollutant precursors has been identified in southern Switzerland. The aims of this project were to assess the extent of ozone-induced foliar injuries in the most highly exposed forests and to confirm the cause of injury by controlled exposures.

Available languages: English

Halocarbon exposure can result in degradation of photosynthetic pigments in trees and affect xenobiotic metabolism in plants. The aim of this project was to determine the levels of trichloroacetate in needles of conifer species in Swiss forests and to compare these with levels in other European forests.

Available languages: English

Since 1993 Prunus serotina showed symptoms typical of ozone injury at many sites in southern Ticino. The aims of this project were to confirm that this foliar injury is caused by ozone and to determine the ozone concentrations that induce the injury.

Available languages: English

Special focus of the Integrated Monitoring of Air Pollution Effects on Ecosystems is to improve the understanding about the effects of sulphur and nitrogen inputs into ecosystems. The research methods are intensive and are carried out within ecosystems in small hydrologically delineated catchments.

Available languages: English

The better understanding of the processes driving the dynamics of forest ecosystems requires the documentation of the constantly interacting compartments and fluxes of the biogeochemical cycle. Scientists study two fluxes (deposition of nutrients through precipitation and litterfall) and two compartments (foliage and ground vegetation).

Available languages: German English

Ozone effects on plants mainly depend on atmospheric transport and stomatal uptake. Thus ozone risk assessments should not only use measured ozone concentrations, but should also account for the influence of atmospheric conditions and soil moisture on stomatal conductance and non-stomatal ozone deposition.

Available languages: English

POPs are Persistent Organic Pollutants which accumulate in organic substances and in the food chain. They can induce cancer and cause acute damage to skin, nervous system and organs at high doses. The Alps seem to be a major sink for long-range transported and globally distributed atmospheric pollutants.

Available languages: German English

Can hourly and daily changes of the circumference of tree stems be used as indicators of tree condition? Can they be used to find the effects of weather and soil water availability on tree growth and vitality? Can the information be used to explain past tree increment? What are the interactions between neighbour trees?

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Present plant/forest communities are the result of long-term interactions between vegetation and site factors including man-made impacts. For more than fifty years people have tried to develop a method to estimate the man-made impacts on vegetation or the vegetation/ecosystem change.

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The Sanasilva Inventory has been carried out in its current form since 1985. Its aim is to monitor the health of the Swiss forest using crown and tree parameters as indicators of forest condition. The name of the inventory has changed subsequently with the change in assessment methods.

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The epicuticular wax layer on the needle surface from conifer trees has been chemically analysed and viewed with a scanning electron microscopy with respect to the needle development at different environmental conditions (SO2 and ozone concentration, climate and site).

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Natural UV-B radiation has been decreased partially or entirely by different plexiglas filters. Reduced UV-B radiation induced in poplar an increased leaf area, assimilatory starch production, and epicuticular wax, but decreased anthocyan content.

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There can be no doubt that since the beginning of the industrial revolution CO2 levels in the air have progressively increased. Experiments on the effects of elevated concentration levels of CO2 and nitrogen deposits on a coniferous/deciduous forest were carried out by natural scientists.

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Mit diesem Kleinprojekt haben die Forschenden Erfahrungen über die Fleckenbildung an Fichtennadeln gesammelt. Dadurch können sie Fleckensymptome besser interpretieren. Die Erfahrung, wie sich das Gewebe in gesunden Nadeln im Jahresverlauf entwickelt, hilft Alterungserscheinungen von anderen Einflüssen zu unterscheiden.

Available languages: German

The aims of this project are to investigate the reactions of trees in the context of above ground (ozone) and below ground pollution (heavy metals). Are the effects of ozone in the air and heavy metals in the soil independent or do they reduce or reenforce each other?

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By sunny weather, when increased ozone concentration lasts longer then 2 weeks, ozone symptoms can appear on leaves and conifer needles. The Validation Centre offers diagnosis, training, information and consulting. Products are an Ozon-Quiz, an Ozone-CD and the International Ozone Injury Database.

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Borkenkäferbefall hat dazu geführt, dass im Kanton Glarus als Folge eines Sturms die Fichten auf 100 Hektaren abgestorben sind. Wie lange können die toten Bäume und liegende Stämme Waldlawinen verhindern und Steinschläge abbremsen? In welcher Zeit wächst wieder ein schutzfähiger Bergwald heran?

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This framework aims to investigate the fluxes in model ecosystem chambers and to trace and better understand the reactions of the plants and associated organisms to the chronic influence of important soil pollutants (Zn, Cu, Cd) and rain acidity.

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Als Folge des Sturmes "Lothar" und der Sommertrockenheit 2003 sind in der Schweiz grossflächige, regionale Buchdrucker-Epidemien im Gang. Wissenschafter dokumentieren den Erfolg der getroffenen Bekämpfungsmassnahmen und stellen Grundlagen für Entscheidungs- und Handlungsstrategien bereit.

Available languages: German

The mission of LWF is to improve our understanding of how natural and anthropogenic stresses affect forests in the long term, and which risks for humans are involved. Consequently, we need to gain a more profound knowledge of the cause-effect relationships in the forest ecosystem and the underlying processes.

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Waldbestände und deren Wurzeln beeinflussen die Bodenstruktur und damit das Porensystem und den Bodenwasserhaushalt entscheidend. Aber nicht jeder Waldtyp schützt gleich gut vor Hochwasser. Wie lässt sich der Abflussbeitrag unterschiedlicher Waldgesellschaften quantifizieren?

Available languages: German

Scientists investigate the reactions of fine roots of spruce and poplar to enhanced heavy metal contents in the soil. They measure growth and architecture of newly derived fine roots of these trees and investigate mycorrhizas of birches in order to localise and quantify the heavy metals on a subcellular level.

Available languages: English

Mit Schwermetallen kontaminierte Böden lassen sich durch Pflanzen sanieren, die grössere Mengen dieser Metalle in den oberirdischen Pflanzenteilen einlagern können und auf diese Weise dem Boden einen grossen Anteil an verfügbaren Schwermetallen entziehen. Dabei ist es wesentlich zu wissen, wie einheimische Bäume mit hohen Schwermetallgehalten umgehen.

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Der Wert eines Waldes geht weit über die Holzproduktion hinaus. Besonders in Ballungsräumen hat die stadtnahe Walderholung grosse Bedeutung für die Bevölkerung. Forschende der WSL untersuchen den Erholungswert des Zürcher Waldes und gehen der Frage nach, wie sich die Bedürfnisse Erholungssuchenden am besten befriedigen lassen.

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Major storms like "Lothar" are a great chance for below-ground studies on root architecture and growth structure. What is the relationship between below- and aboveground biomass accumulation in the past? Are roots the hidden key players?

Available languages: German English