Swiss Federal Institute for Forest, Snow and Landscape Research

About: Swiss Federal Institute for Forest, Snow and Landscape Research is a facility organization based out in Birmensdorf, Switzerland. It is known for research contribution in the topics: Climate change & Soil water. The organization has 1256 authors who have published 3222 publications receiving 161639 citations. The organization is also known as: WSL.

Early Development of Transplanted Isidioid Soredia of Lobaria Pulmonaria in an Endangered Population

Abstract: Vegetative diaspores of Lobaria pulmonaria were transplanted to previ- ously uncolonized trees The early development of the corticated but otherwise non-stratified isidioid soredia was studied mainly by low-temperature scanning electron microscopy Anchoring hyphae developed from cortical hyphae after 2-4 months and later apical or lateral pseudomeristematic growth zones were formed After 15 months the growth zones further differentiated into 0-5-mm-broad lobes and revealed a stratified thallus typical for this foliose epiphytic lichen species The experiment showed that the small population size of L pulmonaria was limited by the low reproductive potential of the species and that it might fail to compensate for a relatively high disturbance, natural or anthropogenic, in the stand U 1995 The British Lichen Society

Seasonal growth, δ13C in leaves and stem, and phloem structure of birch (Betula pendula) under low ozone concentrations

Abstract: The growth of potted birch cuttings (one clone of Betula pendula) was studied under low O3 concentrations (0, 0.050, 0.075, 0.100 μl l-1) throughout an entire growing season. With increasing O3 dose, 20–50% of all leaves formed were prematurely shed, while 40–70% of the remaining foliage displayed advanced discoloration by the end of the season. Ozonation affected the S, P and N concentration of leaves and increased δ13C in leaves and stem, while the CO2 assimilation rate declined with increasing CO2 concentration in mesophyll intercellulars. While whole-plant production correlated negatively with the O3 dose, ozone increased the specific leaf weight (i.e. leaf weight/leaf area, SLW) but decreased the ratios of stem weight/stem length and root/shoot biomass. Neither the latter ratio nor SLW changed in experimentally defoliated control plants, whereas in ozonated plants starch accumulated along leaf veins and phloem tissue was deformed in the leaf petioles and the stem. Only in early summer was the relative growth rate higher in the ozonated than in the control plants. The ratio of whole-plant biomass production versus total foliage area formed was lowered under O3 stress. However, when relating biomass to the actual foliage area present due to leaf loss, this ratio did not differ between treatments. Similarly the ratio of actual foliage area versus basal stem area in cross-section did not differ. Overall, whole-plant production was strongly determined by O3-caused changes in crown structure and began to be limited at O3 doses (approximately 180 μl l-1 h) similar to those of rural sites in Central Europe.

Effects of climatic seasonality on the isotopic composition of evaporating soil waters

Abstract: Stable water isotopes are widely used in ecohydrology to trace the transport, storage, and mixing of water on its journey through landscapes and ecosystems Evaporation leaves a characteristic signature on the isotopic composition of the water that is left behind, such that in dual-isotope space, evaporated waters plot below the local meteoric water line (LMWL) that characterizes precipitation Soil and xylem water samples can often plot below the LMWL as well, suggesting that they have also been influenced by evaporation These soil and xylem water samples frequently plot along linear trends in dual-isotope space These trend lines are often termed “evaporation lines” and their intersection with the LMWL is often interpreted as the isotopic composition of the precipitation source water Here we use numerical experiments based on established isotope fractionation theory to show that these trend lines are often by-products of the seasonality in evaporative fractionation and in the isotopic composition of precipitation Thus, they are often not true evaporation lines, and, if interpreted as such, can yield highly biased estimates of the isotopic composition of the source water

Changes in the species composition and conservation value of limestone grasslands in Northern Switzerland after 22 years of contrasting managements

Abstract: An experiment was established to assess the long-term effects of six different management types on the species composition of dry limestone grasslands with the aim of finding an alternative to the traditional management (mowing annually in July) which is no longer economically viable. In addition to the traditional management (JU1), the following management types were applied experimentally for 22 years: mowing every 2 years in July (JU2), every 5 years (JU5), or not at all (ABN, abandonment), mowing annually in October (OCT), and controlled burning annually (CBR) at the end of winter. There were two study sites, Grate and Gratental, near Schaffhausen in N Switzerland, each with three replicate 5 m×10 m plots for every management. During the course of the experiment, the vegetation was recorded on 10 occasions, yielding 306 vegetation releves containing a total of 124 species. These data were analysed using correspondence analyses (CA). In addition, changes in the abundance of 16 plant species with high cover, high frequency or particular importance for nature conservation were examined in detail. The CA showed that the vegetation of the two study sites differed considerably, but that in both sites the various management types led to changes in floristic composition which were probably continuing even after 22 years. At the end of the experiment, on the Grate site, species number in comparison to JU1 had declined in the following progressive order: OCT, JU2, JU5, CBR, ABN, where it was down to 70%. At the Gratental site, species number showed no clear pattern, because of the immigration of ‘new’ species from the surrounding hedges and agricultural fields. Interestingly, Bromus erectus , the dominant species with a cover of 40–70% at the beginning, decreased to 5–30% under different managements, mainly because the regeneration of its tufts is affected by abandonment and particularly burning. The rhizomatous Brachypodium pinnatum showed the opposite pattern and increased from 5% to 60% in CBR. Trifolium medium as well as Salvia pratensis , Primula veris and other long-lived forbs of high conservation value tended to be favoured by OCT, CBR and/or ABN because they can store nutrients if they are not annually cut in July. On the other hand, several low growing species like Anthyllis vulneraria and Hieracium pilosella need the better light conditions associated with the annual mowing in July for optimal growth. In every management type, some species of high conservation value decreased whereas others increased! According to our results, the best strategy—for achieving and maintaining a high species diversity—is a mosaic of different management types, i.e. a central part of the grassland managed traditionally, i.e. mown annually in July, and large strips at the margins mown only every second year in July or October. When mown in October, the soil has to be nutrient-poor and the site isolated from the seed rain of forest fringe species, which otherwise could become dominant and lead to a decline in species. The alternative of mowing the whole area every second year in July or annually in October (with the same restrictions for mowing in October) it is not completely satisfactory because several species may be lost in the long term.