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Für die waldbauliche Planung haben sich Standorttypen und ihre Darstellung in Ökogrammen bewährt. Damit diese auch in Zukunft nützlich bleiben, ist ein gutes Verständnis der anstehenden Veränderungen durch den Klimawandel notwendig. Die Verschiebung der Vegetationshöhenstufen mit dem Klimawandel wurde bereits berechnet und beschrieben. Es blieb jedoch offen, ob sich zusätzlich zu der Verschiebung der Vegetationshöhenstufen auch eine Verschiebung der Vegetationseinheiten auf der Feuchteachse des Ökogramms ergeben wird, verursacht durch die Zunahme der Trockenheit. Auswertungen von 1044 Vegetationsaufnahmen mit Bodenprofilen ergaben, dass die Feuchteachse vor allem durch die Bodenphysik (Vernässung, nutzbare Feldkapazität) und die Eigenschaften der Topografie (Kuppenlage, Exposition und Neigung) erklärt wird. Der Klimaeinfluss war weniger wichtig. Wichtigste erklärende Klimavariable war das Dampfdrucksättigungsdefizit der Luft, während Niederschlag oder Trockenheitsindikatoren nur einen geringen Einfluss hatten. Berechnungen mit zukünftigen Klimadaten prognostizieren eine Verschiebung innerhalb der Feuchteachse um etwa 9% der Skala. Das ist zu gering, um die Position von Vegetationseinheiten auf der Feuchteachse markant zu verändern.

Foresters from many countries are seeking for tree species or provenances able to cope with expected climate change. While it becomes clear that some temperate tree species will increasingly suffer from climate warming, the fate of the ecologically and economically important silver fir (Abies alba Mill.) remains uncertain and debated because the ecological requirements of this species, as well as its resilience to drought, are still unclear. On the one hand, paleoecological studies reveal that this species was widely distributed under much warmer climate, suggesting a high potential to cope with ongoing and future climate warming. On the other hand, species distribution models generally predict a strong decline of its climatic suitability in the future. This paper aims to clarify the potential of this species to thrive in central and western Europe under predicted climate warming by reviewing the knowledge gained from different fields. Based on insight from different fields, we argue that silver fir has a great potential to thrive under warmer conditions in western and central Europe provided sufficient rainfall, as forecasted by climate models for most regions by 2100. For instance, dendroecological studies demonstrate that silver fir is more resistant and resilient to drought compared to co-occurring species such as Norway spruce, European beech and larch. The most prominent obstacle for increasing the proportion of fir in mixed forests nowadays is ungulate browsing that often prevents its upgrowth.

Aims Climate change is expected to markedly change site factors, tree species composition and finally ecosystem services provided by forests. Here, we describe the development of a framework for modelling how these changes may transform forest site types. Site types capture information on site conditions like climate, topography and soil, all factors with strong influence on tree species occurrence. Location Switzerland. Methods We elicited expert knowledge and followed a participatory modelling approach for quantifying upward shifts of altitudinal vegetation belts and the changes in the zonal distribution of main tree species, as a basis for assessing transformation pathways of forest site types for three climate projections. Results The model results show marked range shifts of altitudinal vegetation belts. The change in the vegetation belt and a rule base for forest site type transformations allow for assessing the location-specific and long-term transformation pathway from the current to a future forest site type. Conclusions The resulting maps enable forest managers to take climate change into account when selecting tree species. The presented method complements statistical distribution models as it considers more site information, integrates expert knowledge and is based on a forest site type classification which is already widely used by forest practitioners., Applied Vegetation Science, 24 (4), ISSN:1402-2001, ISSN:1654-109X

What future for silver fir in Switzerland under ongoing climate change? Foresters in many countries are currently seeking for the most suitable forest species or provenances for facing the future climate, which will be much warmer than today with more extreme summer droughts. While it is clear that some tree species will increasingly suffer from climate warming, the fate of silver fir (Abies alba Mill.) remains very uncertain because contradictory results have been published about the suitability of this species to cope with climate warming. On the one hand, species distribution models predict a strong decline of its climatic niche in the future. On the other hand, paleoecological studies reveal that this species was widely distributed under much warmer and probably drier climate, suggesting a high potential to face future climate warming. This literature survey shows that this species could actually grow under warmer conditions provided that precipitation remains sufficient, which seems to be the case for most regions of Switzerland according to climatic model predictions for the end of the century. In addition, dendroecological studies have shown a higher resistance and resilience of silver fir to drought compared to Norway spruce, suggesting that silver fir could be promoted by foresters. Nowadays, the greatest threat to silver fir is undoubtedly the browsing pressure by ungulates which can jeopardize its regeneration and must therefore be properly regulated to increase the proportion of silver fir in Swiss mixed forests.

Modelling of the vegetation belts and the areas of beech and silver fir for Switzerland The vegetation belts and the distribution area of beech and silver fir in Switzerland are an essential basis for the classification of forest site types with ecograms and therefore for site-specific recommendations of tree species and for forestry. Their limits, which are to a large extend defined by climatic factors, were until now only defined on a qualitative basis. For the future usage of the ecograms for tree species recommendations the limits must be described quantitatively, so that they can be modelled for the future with climate scenarios. With maps in a high spatial resolution of the forest-relevant climate variables and with additional important site parameters, those parameters were selected, which were relevant for the actual limits of the vegetation belts as well as for the beech and silver fir areal. The altitudinal belts were modelled by means of a linear regression between the known position of a representative altitudinal limit and the respective climatic factors at that position. The areal limits were modelled with a fuzzy logic approach. The climatic variables for the time span 2070–2099 were calculated on the basis of the climate (emission) scenario A1B (regional models RegCM3 and CLM), so that the limits of the altitudinal belts and the areas could be modelled for the future. The results of the model approaches are ecologically plausible. This could be shown in a comparison with the forest site types on the sample points of the National Forest Inventory and in an expert evaluation. The developed vegetation and climate maps as well as the modelled projections of the altitudinal belts in the future are the basis for the inclusion of climate change in the recommendation of tree species. They serve as decision support for forest managers and authorities in the forestry planning which is confronted with many uncertainties.

State and development of drought in Swiss forests Climate scenarios for the 21st century for Switzerland show increasing temperatures and more frequent weather extremes and the risk of drought will become more important. The objective of the study was the calculation of indicators which allow the estimation and evaluation of drought risks on a regional scale. The site water balance and the ratio between actual and potential evapotranspiration (ETa/ETp) were used as indicators. They are closely related to vitality parameters of trees. For projections in the future were used the A1B climate scenario, which assumes a warming of 2.7 to 4.1°C in Switzerland, and three regional climate models (CLM, RCA, REGCM3), which predict different developments regarding precipitation and temperature. Historical time series between 1951 and 2012 and scenarios up to 2100 for different climatic regions were calculated. The indicators reproduce well the measured trends and the regional differences. In all regions there was in the past a trend to increased drought. The Geneva/ Vaud region as well as the western midlands and north Switzerland show the most pronounced changes. Projections with the CLM model (which reproduced best the historic trend 1981–2010 for Switzerland) show increasing drought and, in general, an increasing variability of the climate for the mid-century.

Deposition of air pollutants in Switzerland: development, current situation and assessment In total, the emissions of nitrogen, sulfur and other anthropogenic air pollutants in Switzerland were reduced in the last decades. This is the result of effective measures of the air pollution abatement policies. Sulfur input in forests today is nearly negligible due to a reduction of emissions by more than 90 percent. Regarding nitrogen emissions the picture is less consistent: they are reduced in consequence of the abatement of nitrogen oxides emissions from combustion processes, but ammonia emissions from agriculture show a considerably less pronounced reduction, and since the year 2000 they remain on a high level. In 2007 the average inputs in forests amounted to 24 kg nitrogen per ha and 4.8 kg sulfur per ha. Natural nitrogen input is 1 to 3 kg per ha and year. On nearly all forest sites (>95%) the critical loads for nitrogen were exceeded. Nitrogen input consists of roughly two thirds of reduced ammonia nitrogen from agricultural activities and one third of oxidized nitrogen from combustion processes (traffic, households, industries, commerce). In 2007 the acidification potential of nitrogen and sulfur input in forests on many sites was considerably higher than the amount of available neutralizing cations (Ca, Mg, K) from the weathering of minerals and their input with dust. Further efforts are necessary to reduce the nitrogen load in forests to a tolerable amount.

The standardised Ginkgo biloba extract EGb761 is known for its potential beneficial effects in the prevention and therapy of neurodegenerative disorders including Alzheimer's disease (AD). However, the molecular mechanisms and the specific role of its constituents are largely unknown. The aim of the present feeding trial was to investigate the effects of EGb761 and its major constituents on the expression of genes encoding for proteins involved in the pathogenesis of AD in mouse brain. Six month old C57B6 mice were fed semi synthetic diets enriched with either EGb761 or one of its main fractions, flavonols and terpenelactones, respectively, over a period of 4 weeks. Thereafter, mRNA of alpha-secretase, neprilysin, amyloid precursor protein (App), App binding protein-1 and acetylcholine esterase was quantified in hippocampus and cortex. EGb761 and its flavonol fraction had no effects on relative mRNA levels of the respective genes in mouse brain. However, the terpenelactone fraction significantly decreased the mRNA levels of App in the hippocampus. Taken together, a 4 week dietary treatment with EGb761 or its main fractions had only moderate effects on mRNA levels of AD related genes in cortex and hippocampus of mice.

Numerous clinical trials have reported beneficial effects of the Ginkgo biloba extract EGb761 in the prevention and therapy of cognitive disorders including Alzheimer's disease (AD). Although neuroprotective properties of EGb761 have been consistently reported, the molecular mechanisms of EGb761 and the specific role of its major constituents, the flavonols and terpenlactones, are largely unknown. One major hallmark of AD is the deposition of amyloid-beta (A beta) as amyloid plaques in the brain. A beta is a cleavage product of amyloid precursor protein (APP). Certain proteases, called beta-secretases (BACE), are crucial in the formation of A beta. The purpose of the present study was to investigate the efficacy of EGb761 and its flavonol and terpenelactone fraction to modulate BACE-1 enzyme activity and mRNA levels in vitro and in vivo. Neither EGb761 nor its fractions affected BACE-1 activity in vitro. Furthermore, also in Neuro-2a cells and wild-type as well as transgenic (Tg2576) laboratory mice, no significant effect of EGb761 on BACE-1 enzyme activity and mRNA levels were observed. Current findings suggest that BACE-1 may not be a major molecular target of EGb761 and its flavonol and terpenelactone fraction.

The calculation of critical loads and their exceedance is one method to describe the vulnerability of forests to environmental stress caused by anthropogenic impact. Exceedance of critical loads for acidifying inputs and nitrogen was compared to different indicators of the soil and forest conditions in the German part of the extensive forest monitoring (ICP Forests/EU Level I), including more than 1,800 plots. In addition, an empirical relationship between the C/N ratio of the forest floor humus layer (C/NHumus) and the estimated nitrogen output for ten plots of the intensive monitoring (ICP Forests/EU Level II) was established in order to estimate the potential nitrogen output on Level I plots dominated by Norway spruce. Regarding all tree species assessed, the exceedance of critical loads for nitrogen and sulphur is negatively correlated with pH and base saturation up to 30 cm soil depth. The sulphur deposition and the exceedance of critical loads are highly correlated with the sulphur content of leaves and needles, whereas the respective relations for nitrogen were lower. The crown condition was weakly positively related to the sulphur content in tree leaves and needles. For Norway spruce sites, high exceedance of critical loads for nitrogen and nitrogen deposition corresponded well with low C/NHumus. In regions with high nitrogen load and low C/N ratios in the humus layer, the calculated nitrogen output was high. The results support the concept of critical thresholds in that way that their exceedance can impair forest ecosystem functions like nitrogen retention.

Element concentrations in tree rings can be used to monitor changes in environmental quality. With regard to the detection of incipient soil acidification, the manganese concentration in soils and plants is a significant marker for the switch of acid buffering in soils mainly with the exchange of base cations or with the dissolution of aluminium oxides. This is a site-specific non-linear event, indicating the onset of Al3+ dominance in the soil solution, were damages to vegetation due to acid stress become possible. This turning point is also a marker for the attainment of pH 4.2 in soils, the critical threshold used for critical load calculations. On a plot of the German environmental monitoring in forests the element concentrations in tree rings of 60-year-old spruces reveal a distinct decline in the Mn concentration, beginning in the late 1960s ending in the late 1970s. With this information it was possible to assume a base saturation in the soil of about 15–20% in the late 1960s, and to model the development of the base saturation of the site. A decline from 17.5 to 6% within one decade could be related to the deposition. This is in accordance with the base saturation of 6.5%, measured in 1993 for this site, but also for adjacent spruce sites on the same geological substrate. The knowledge of the time span were this site-specific non-linear event occurred is essential for the reconstruction of the soil chemistry of a site. Moreover, it enables the assignment of observations like ‘forest damages’ to the onset of changes in environmental quality.

In the 1970s unexpected forest damages, called “new type of forest damage” or “forest decline”, were observed in Germany and other European countries. The Federal Republic of Germany and the German Federal States implemented a forest monitoring system in the early 1980s, in order to monitor and assess the forest condition. Due to the growing public awareness of possible adverse effects of air pollution on forests, in 1985 the ICP Forests was launched under the convention on long-range transboundary air pollution (CLRTAP) of the United Nations Economic Commission for Europe (UN-ECE). The German experience in forest monitoring was a base for the implementation of the European monitoring system. In 2001 the interdisciplinary case study “concept and feasibility study for the integrated evaluation of environmental monitoring data in forests”, funded by the German Federal Ministry of Education and Research, concentrated on in-depths evaluations of the German data of forest monitoring. The objectives of the study were: (a) a reliable assessment of the vitality and functioning of forest ecosystems, (b) the identification and quantification of factors influencing forest vitality, and (c) the clarification of cause-effect-relationships leading to leaf/needle loss. For these purposes additional data from external sources were acquired: climate and deposition, for selected level I plots tree growth data, as well as data on groundwater quality. The results show that in particular time series analysis (crown condition, tree growth, and tree ring analysis), in combination with climate and deposition are valuable and informative, as well as integrated evaluation of soil, tree nutrition and crown condition data. Methods to combine information from the extensive and the intensive monitoring, and to transfer process information to the large scale should be elaborated in future.

The effects of local climate and silvicultural treatment on the inorganic N availability, net N uptake capacity of mycorrhizal beech roots and microbial N conversion were assessed in order to characterise changes in the partitioning of inorganic N between adult beech and soil microorganisms. Fine root dynamics, inorganic N in the soil solution and in soil extracts, nitrate and ammonium uptake kinetics of beech as well as gross ammonification, nitrification and denitrification rates were determined in a beech stand consisting of paired sites that mainly differed in aspect (SW vs. NE) and stand density (controls and thinning treatments). Nitrate was the only inorganic N form detectable in the soil water. Its concentration was high in control plots of the NE aspect, but only in canopy gaps and not influenced by thinning. Neither thinning nor aspect affected the abundance of root tips in the soil. Maximum nitrate net uptake by mycorrhizal fine roots of beech, however, differed with aspect, showing significantly lower values at the SW aspect with warm–dry local climate. There were no clear-cut significant effects of local climate or thinning on microbial N conversion, but a tendency towards higher ammonification and nitrification and lower denitrification rates on the untreated controls of the SW as compared to the NE aspect. Apparently, the observed sensitivity of beech towards reduced soil water availability is at least partially due to impaired N acquisition. This seems to be mainly a consequence of reduced N uptake capacity rather than of limited microbial re-supply of inorganic N or of changed patterns of inorganic N partitioning between soil bacteria and roots.

Although the composition of the soil solution has important ecological information, there is no general consensus for obtaining and analyzing of the soil solution. This study presents an alternative procedure to obtain the soil solution and determine all relevant anions and cations. The soil samples are taken with an auger. 10—20 g of field moist soil are desorbed in a pressure chamber at 170 kPa (pF 3.2), with a cellulose acetate membrane filter (∅ < 0.45 μm) as capillar bridge between the interior and exterior of the chamber. The desorption procedure is performed at 4°C for 24 hours and yields up to 1.0 ml soil solution, depending on the actual water potential. If more soil solution is needed, the soil may be replaced by another aliquot of the same sample. 0.15 ml of soil solution is sufficient for analysing all cations and anions, which account quantitatively for the ion balance with a capillary electrophoresis. Compared with suction cups, ion concentrations in desorption solutions are, although generally lower, in the same order of magnitude. The advantage of this method is that no field equipment is needed, apart from the auger. Even in heterogeneous forest soils, water soluble ions can be monitored with a high spatial resolution and without any dilution effects, which are common in the most laboratory methods. The problem of lacking spatial representativity in stationary lysimeter stations is also overcome. Additionally it is possible to obtain and analyze soil solutions in a suction range where suction cups fail. Die Desorptionslosung — ein alternativer Ansatz zur Bestimmung wasserloslicher Ionen in Boden Obwohl die Zusammensetzung der Bodenlosung hohen okologischen Informationsgehalt besitzt, gibt es keinen generellen Konsens uber ihre Gewinnung und Analyse. Es wird ein neues Verfahren zur Gewinnung und Analyse der Bodenlosung vorgestellt. Bodenproben werden mit einem Bohrstock entnommen, 10—20 g feldfrischen Bodens werden in einer Druckkammer bei 170 kPa (pF 3.2) desorbiert. Dabei dient ein Cellulose-Membranfilter (∅ < 0.45 μm) als kapillare Brucke zwischen dem Kammerinneren und dem Auslass. Die Desorption erfolgt bei 4°C, in 24 Stunden konnen — je nach Bodenfeuchte — bis zu 1.0 ml Bodenlosung gewonnen werden. 0.15 ml Bodenlosung sind fur die Analyse aller bilanzrelevanten Kationen und Anionen mittels Kapillarelektrophorese erforderlich. Die Konzentrationen in der Desorptionslosung sind im Vergleich zu Losungen aus Saugkerzenanlagen meistens geringer, liegen jedoch in der gleichen Grosenordnung. Der Vorteil der Methode ist, dass — abgesehen von einem Bohrstock — kein weiterer technischer Aufwand im Feld erforderlich ist. In heterogenen Waldboden kann so z.B. der Gehalt wasserloslicher Ionen mit hoher raumlicher Auflosung gemessen werden, ohne dass Verdunnungseffekte auftreten, wie sie bei den meisten Labormethoden ublich sind. Daruber hinaus gibt es — im Gegensatz zu Saugkerzenanlagen und Lysimetern — weniger Probleme mit unzureichender Flachenreprasentativitat. Es ist auch moglich, Bodenlosungen bei Wasserspannungen zu gewinnen, die auserhalb des Einsatzbereiches von Saugkerzen liegen.

Over time environmental monitoring has produced an immense amount of data that was collected in order to assess environmental pollution impacts but also for ecological research. Although this research produced revelatory, valuable data and information on the structures and functions of ecosystems, amazingly few studies have focussed on the theoretical aspects of ecosystem evolution. This obviously is counter to the progress in the field of ecosystem theory and the provision of integrated concepts in relation to indicators of ecosystem performance. In this regard, the major intention and challenge of LTER (Long-Term Ecosystem Research) is to combine the theoretical background with the ecological knowledge already available in order to extrapolate monitoring information about environmental problems and to find solutions in line with recent progress at the global scale. With a view of ecosystem evolution in a long-term perspective and to support applied ecology with respective monitoring information, special methodical diligence has to be lenient towards temporal and spatial extrapolations. This focuses on problems of representativity and reference. The aim of this chapter is to inform the reader how information on ecosystems can be derived and the potentials and limitations of using available databases from monitoring in networks and results produced by integrated data evaluations in ecosystem research. Ideas on further optimisation of monitoring activities are also presented. Two environmental initiatives are presented as case studies including protection of forest ecosystems against the effects of atmospheric deposition (ICP-forests) and the definition of properties that define a good ecological state of aquatic ecosystems (European Water Directive); critical load indications and success control measures are respectively used and the benefits to environmental protection are discussed.