Eidgenossische Forschungsanstalt fur Wald

Birmensdorf, Switzerland

Eidgenossische Forschungsanstalt fur Wald

Birmensdorf, Switzerland
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Holderegger R.,Eidgenossische Forschungsanstalt fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2016

Swiss forests are managed in a close-to-nature way, and they mainly get naturally rejuvenated. This leads to a forest situation most beneficial for the conservation of the genetic diversity of forest trees. If tree breeding and artificial planting are not main targets in Switzerland, why then using genetics in Swiss forests? In fact, the applications of genetic methods in forests are manifold. They can be used for the identification of connectivity and the evaluation of the success of connectivity measures, e.g., among total reserves, old-growth stands and habitat trees. With genetic methods, one may also study how native tree species and their genetic varieties can best be used for adaptation to climate change. Other applications comprise the investigation of biodiversity and ecology, e.g., the influence of forest management on soil biodiversity, or the diagnosis of invasive pests and pathogens and the search for agents of biological control. In the framework of multifunctional forest management, genetic applications can play an important role, if used in a sensible way.


Rellstab C.,Eidgenossische Forschungsanstalt fur Wald | Pluess A.R.,Eidgenossische Forschungsanstalt fur Wald | Gugerli F.,Eidgenossische Forschungsanstalt fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2016

Forest trees will have to adapt to future climatic changes, a process that will comprise genetic changes as a key component. Owing to technological advances it is now possible to identify the signature of natural selection and local adaptation in the genome. Environmental association analyses aim at associating adaptive genetic patterns with environmental parameters describing the local habitat. On the basis of such studies - including own investigations using oak and beech in Switzerland-, we show that forest trees are genetically differentiated along various environmental gradients, especially temperature and precipitation. Numerous genes could be found that presumably play a role in the adaptation to such environmental factors. Based on these findings, one could identify trees or stands that are adapted to future local conditions, and respective seed material could be considered in silviculture. Because such approaches are still in their infancy and because genome-environment interactions are complex, management strategies should focus on the preservation of (adaptive) genetic diversity, natural regeneration, and connectivity among stands. This would set the basis for the local adaptation of forest stands to altered environmental conditions by natural processes.


Olschewski R.,Eidgenossische Forschungsanstalt fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2017

Since the publication of the Millennium Ecosystem Assessment in 2005, the number of studies on the economic valuation of ecosystem services has increased. At the same time manifold doubts are raised concerning the concept of ecosystem services. On the one hand there are knowledge gaps related to the biophysical provision of such services, on the other hand methodological problems exist concerning 1) the determination of individual and social preferences as well as 2) the valuation approach in general. The present article addresses critical aspects of economic valuation methods. It concludes that it should not be striven for the one perfect method, but rather to look for ways to improve and integrate the different approaches. Promising initiatives are the comprehensive assessment of the available knowledge within the framework of the Intergovernmental Platform on Biodiversity and Ecosystem Services, and the development of common valuation standards.


Zellweger F.,ETH Zurich | Bollmann K.,Eidgenossische Forschungsanstalt fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2017

Availability of comprehensive biodiversity maps and standlevel habitat management recommendations to forest services is often limited, despite the need for such information for multifunctional forestry. Here, we combined forest structural parameters derived from nation-wide available Light Detection and Ranging (LiDAR) data with parameters describing climate, topography and soil pH, to analyse and spatially predict the species richness of different taxa on two different scales. Vascular plants, bryophytes and land snails were analysed on the stand scale (900 m2), where we also identified target variables for habitat management by using data from the National Forest Inventory. On the landscape scale (1 km2), we analysed vascular plants, butterflies and breeding birds with a tight association to forests. LiDAR-derived forest structure parameters were consistently important predictors of species richness across taxa. Species richness patterns tended to be taxon-specific with low spatial congruence across taxa. The habitat quality for many forest land snail species, for example, increased with increasing proportions of trees from the genera Fraxinus, Tilia, Ulmus and Acer, or with increasing overstory cover and deadwood volume. Many butterfly species, on the other hand, responded positively to a heterogeneous understory. This study shows that important structural parameters for forest biodiversity can be derived area-wide and across large regions by using LiDAR. The growing availability of LiDAR data thus provides very useful information for conserving and promoting biodiversity in multifunctional forestry.


Seidl I.,Eidgenossische Forschungsanstalt fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2015

Future land use may well lead to increasing conflicts between the competing demands for this scarce and limited resource given demands, interests and societal developments. Three approaches to dealing with land use are proposed: multifunctionality, quality of land use and sufficiency. Additionally, beauty needs to gain in importance. The foundation for the proposed approaches needs to be an institutional and cultural transformation that includes the construction industry, the ideological basis of municipal planning, as well as the societal drive for growth, and money creation.


Kaufmann E.,Eidgenossische Forschungsanstalt Fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2011

In the Swiss National Forest Inventory (NFI), the data collected in the three inventories (NFI1 1983-1985, NFI2 1993-1995, NFI3 2004-2006) provide the basis not only for analysing the present state of the forest and how it has developed up to now, but also for assessing, with the help of models, how it might develop in future. The scenario model «Massimo 3», developed at the Swiss Federal Institut for Forest, Snow and Landscape Research, is an empirical and stochastic simulation model. It relies on data from the NFI and forecasts the development of the forest according to how it is managed. Six scenarios with different management regimes were defined according to the economic, silvicultural and ecological aspects considered. In three scenarios the growing stock is kept constant at the level of NFI3, but different management strategies are used (Scenario A: basis [business as usual], Scenario E: even-aged forests are transformed into uneven-aged forests, and Scenario F: near-natural percentages of conifers are promoted). In two scenarios forest management is partially abandoned for either ecological reasons (Scenario B: reservations, 10% of the forest area is left unmanaged) or for economic reasons (Scenario C: harvesting costs, 40% of the forest area is left unmanaged). Scenario D (rotation periods are shortened) was used to study the effects of augmenting the annual harvesting amount. A forecasting time period of 100 years was selected to assess the long-term effects of the scenarios. Scenarios A, D, and E show that the sustainable harvesting potential of merchantable wood lies in a relatively narrow range of 7.1 to 7.3 million m3/year, even though in Scenario D the growing stock is reduced from 360 m3/ha to 305 m3/ha. In Scenario F regeneration is systematically established with near-natural percentages of conifers, the long-term harvesting potential is slightly less: about 6.5 million m3/year of merchantable wood. If forest management is abandoned for economic reasons on as much as 40% of the forest area (Scenario C, harvesting costs), the impact on the wood reserves is very negative.


There is an increasing interest on area-wide and high-resolution data of forest composition. In Switzerland, tree species distribution will be considered periodically by the Swiss National Forest Inventory (NFI), but the claims will be only partly fulfilled by the existing forest type maps since they are relatively poor regarding spatial accuracy, updating, and reproducibility. Providing consistent, reproducible and up-to-date information on various forest parameters is the main advantage of using the latest remote sensing data and methods. New possibilities are given by the airborne digital sensor ADS80, which records the entire country during the vegetation season every six years. This paper presents a robust methodology of classifying tree species in different study areas. The obtained accuracies for beech, ash, Norway spruce, Scots pine, larch, willow and silver fir are in average 71-85%, but lower for other deciduous tree species. These are mainly less dominant tree species within a study area such as maple and birch. A small sample data set and shadows of other neighboring trees seem to be the main reasons for this. Based on the experiences made in this study, a country-wide classification of tree species has become more feasible. The usage of airborne digital sensor ADS80 data in combination with a high degree of automation from the developed methods will enable the generation of country-wide products on the distinction of coniferous and deciduous tree species until 2015.


Wermelinger B.,Eidgenossische Forschungsanstalt fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2014

The rate of introduction of non-native insects and other arthropods to Europe has been exponentially increasing in recent decades, amounting to 20 species per year in the past ten years. By 2008, a total of 1590 species had been introduced since the discovery of America. The main causes are the intensification and globalization of international trade. The most important pathways are trade in ornamental plants and import of goods in infested wooden crates. Most often new species first establish in residential areas, where the normally mild climate favors the survival of exotic species. Three species recently introduced from East Asia to Switzerland are particularly relevant to forests: the box tree moth (Cydalima perspectalis) has infested box tree stands near Basel, the chestnut gall wasp (Dryocosmus kuriphilus) now covers almost all of southern Switzerland, with single infestations also on the Swiss Central Plateau, and two infestation spots of the Asian longhorned beetle (Anoplophora glabripennis) have been identified. Potential future species of invasive insects are discussed. The largescale introduction of foreign tree species in forests needs to be critically examined, as they may be hosts of current and future non-native insects.


Kolly A.C.,Eidgenossische Forschungsanstalt Fur Wald | Kupferschmid A.D.,Eidgenossische Forschungsanstalt Fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2014

Browsing of silver fir (Abies alba) saplings by ungulates is one of the most important issues concerning decreasing regeneration of this tree species. In addition to genetic drivers, environmental factors such as light availability play an important role for the response of a browsed tree. Using an experimental design with fences, we investigated the influence of natural browsing on tree growth along a light gradient. The few fir saplings that responded by flagging up a lateral shoot compensated the browsing induced height difference compared to unbrowsed trees within four vegetation periods. Most firs however reacted with new shoots and remained smaller than unbrowsed ones. The more often a fir sapling was damaged on its terminal shoot, the smaller the tree remained. A positive relation between tree height and light was found only up to a canopy openness of 11%. Mortality over the whole five years was high in low light (<10%) and in forest gaps (>15%), due to desiccation, competition with other plants or browsing (50% of total mortality). We recommend regenerating firs under moderately shaded conditions.


Wohlgemuth T.,Eidgenossische Forschungsanstalt fur Wald | Kramer K.,Eidgenossische Forschungsanstalt fur Wald
Schweizerische Zeitschrift fur Forstwesen | Year: 2015

Tree regeneration in Swiss forests after winter storms Lothar (1999) and Vivian (1990) was analysed based on a sample of 90 totally wind damaged forest gaps of at least 3 ha size, located in the Jura Mountains, the Central plateau, the Prealps and parts of the Alps. In the less elevated Lothar gaps (∅ 860 m a.s.l.) mean stem densities in no intervention gaps (NI) were 7,644 and in salvage logged gaps (SL) 10,786. Means in Vivian gaps (∅ 1428 m a.s.l.) were significantly smaller with 2,572 in NI and 4,600 in SL gaps. Pre-storm regeneration in Lothar gaps amounted to one third of the total stem density and in Vivian gaps to one tenth. The ten tallest trees in both Lothar and Vivian gaps were similar sized with 6.3 m and 6.5 m in average. Most abundant tree species were beech (Fagus sylvatica), sycamore (Acer pseudoplatanus), ash (Fraxinus excelsior) and Norway spruce (Picea abies) in Lothar gaps, and Norway spruce, sycamore and rowan (Sorbus aucuparia) in Vivian gaps. Stem density increased with soil pH and decreased with elevation and the portion of tall herbs, raspberry and blackberry. The deadwood volume amounted to average 266 and 285 m3 per ha in NI gaps of Lothar and Vivian, respectively. In the SL gaps, volumes averaged to 74 and 76 m3 per ha, respectively. Deadwood as regeneration substrate matters predominantly in forests at higher elevations and favouring Norway spruce in particular. Natural regeneration takes place in all studied forest gaps, sooner or later. To achieve specific forest aims, however, competing understory vegetation needs to be controlled. Our results serve as a reference for tree regeneration in wind damaged forests of Central Europe.

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