Showing papers by "Swiss Federal Institute for Forest, Snow and Landscape Research published in 1996"

Tree-Ring Density Networks for Climate Reconstruction

Abstract: Conifers from regions with cool-moist summers (all mountains and the boreal conifer belt) are a suitable source of material for building a radiodensitometric tree-ring network in the northern hemisphere north of 40° latitude. Intra-annual densities from rings as small as 30 microns can be analysed using recently improved densitometric techniques. Networks of living conifers provide densitometric data that can be calibrated against instrumental temperatures and rigorous statistical comparisons clearly demonstrate that these data can be used to represent spatial patterns of temperature variability on annual and decadal timescales over, at least, the last 400 years. Continuous multimillennial chronologies of densitometric data are currently under construction in areas such as the Alps, northern Fennoscandia and Siberia (both the Yamal and Taimyr Peninsulas). Large numbers of logs and stumps that could provide material for the construction of many further high-quality multimillennial chronologies are known to exist in river sediments and lakes in the permafrost zone of northern Russia. Subfossil spruce in the boreal zone of northern North America are apparently rare. Relatively little densitometry has been undertaken in the southern hemisphere and what limited results have been produced seem to indicate that densitometric data offer little additional information, at least as regards temperature sensitivity, above that provided by more commonly analysed tree-ring width data.

The effects of ozone and nutrient supply on stomatal response in birch (Betula pendula) leaves as determined by digital image‐analysis and X‐ray microanalysis

Abstract: SUMMARY Cuttings of Betula pendula Roth were grown in field fumigation chambers throughout one growing season in filtered air with < 3 nl l−1 O3 (control; C) or day/night = 90/40 nl 1−1 O3 (ozone fumigation: O3). Plants were watered with either low (0·005 %: LF) or high-concentrated (0·05%: HF) fertilizer solution. Discs between second-order veins in the central portion of the leaves were excised and immediately cryofixed in liquid nitrogen for low-temperature scanning electron-microscopy (LTSEM) at 1000 hours and 1400 hours. Stomatal width, area and density were measured by digital image-analysis. X-ray counts of potassium (K) and calcium (Ca) ions were determined by means of energy-dispersive X-ray microanalysis in guard and subsidiary cells. Accurate and fast measurements of stomatal apertures by image analysis were possible in birch leaves, because the darkness of the stomatal pore contrasts with the brightness of the guard cells and the cuticular ledges. Regression analysis showed a close relationship between the stomatal width and the pore area (r= 0·938, P < 0·01). At all harvest times, the stomatal pores were significantly narrowed in the high fertilization control treatment (O3/HF vs. O3/LF), and in the ozone treatment at 1400 hours (O3/HF vs. C/LF). In addition to this fertilization effect, ozone had also narrowed the stomatal pores (O3/HF vs. C/HF at 1400 hours, O3/LF vs. C/LF at all harvest times). In addition to these functional effects, morphological effects (individual leaf area, stomatal density) were determined. Single-leaf area was increased by high fertilization, with a tendency to decrease with O3 fumigation. The stomatal density in intercostal fields was increased by O3 but decreased by high fertilisation. Stomatal widening was accompanied by increased K count rates in the guard cells, in contrast to constant K values in the subsidiary cells, irrespective of the fumigation or fertilization regimes. Calcium counts in the guard cells were similar to those in the subsidiary cells, and were independent of the aperture width. In samples with established ozone injury, the K/Ca ratio in collapsed guard cells increased compared with turgid guard cells irrespective of the pore aperture. Collapsed subsidiary cells only differed from turgid subsidiary cells when the guard cells had also collapsed and thus closed the pore.

Chrysoperla lucasina (Lacroix): a distinct species of green lacewing, confirmed by acoustical analysis (Neuroptera: Chrysopidae)

Abstract: The existence of cryptic, sibling species, distinguished principally by vibrational courtship songs, has been confirmed for the carnea-group of Chrysoperla green lacewings in Europe and western Asia. One member of this species-group, C.lucasina (Lacroix), is characterized by several morphological traits as well, but its taxonomic validity has been considered uncertain due to the subtle and variable nature of those traits. Here, we describe the calling and courtship songs of C.lucasina, which uniquely distinguish that taxon from all other members of the carnea-group in Europe. The male of C.lucasina produces two slightly but consistently different types of songs, one while calling and the other while dueting with a female. The female produces just one type of song, identical to the male’s calling song, which is used for both calling and dueting. Measured features of the songs of C.lucasina are nearly invariant over a broad geographical area, from the Canary Islands to Cyprus and from northern Africa to the U.K. Similarly, at least one morphological feature, the presence of a dark stripe on the pleuron of the second abdominal segment, characterizes all adult individuals identified acoustically as C.lucasina. Furthermore, larval head markings vary little among different populations of the song species. We conclude that C.lucasina is a valid biological species, which can also be recognized in museum collections by a suite of morphological attributes. We also briefly compare the songs and adult morphology of C.lucasina with five other currently unnamed song species of the carnea-group whose geographic ranges overlap extensively with it.

Influence of ectomycorrhization and cesium/potassium ratio on uptake and localization of cesium in Norway spruce seedlings

Abstract: Norway spruce (Picea abies (L.) Karst.) seedlings growing in a growth pouch system were used to investigate the effects of the ectomycorrhizal fungus Hebeloma crustuliniforme (Bull. ex St. Amans) Quel. and various Cs/K ratios on the uptake of (134)Cs, expressed as a percentage of the total amount of (134)Cs supplied. The amount of (134)Cs taken up by seedlings increased with increasing Cs/K ratio. At a Cs/K ratio of 0.1, uptake of (134)Cs ranged between 7.2 and 7.3% and was independent of ectomycorrhizal status, whereas at Cs/K ratios >/= 1 uptake of (134)Cs varied from 8.1 to 11.1% for ectomycorrhizal and from 10.4 to 14.4% for non-inoculated plants. Ectomycorrhizal seedlings contained a lower concentration of (134)Cs than non-inoculated seedlings. Among plant parts, the amount of (134)Cs was significantly lower in needles and lateral roots of ectomycorrhizal seedlings compared with non-inoculated seedlings. Among fungal and seedling tissues, highest X-ray net counts of (133)Cs were measured in fungal hyphae of ectomycorrhizal mantles. X-Ray net counts of (133)Cs in lateral roots of ectomycorrhizal and non-inoculated plants were similar, but 5 to 10 times higher than in main roots and needles, suggesting an accumulation of (133)Cs in lateral roots and slow translocation to other plant parts. In contrast, X-ray net counts of K indicated that K was readily mobilized from lateral roots to main roots and needles. Elemental mapping showed a relatively homogeneous distribution of (133)Cs within the root.

A New Graphical Tool to Detect Non-Normality

Abstract: A new graphical tool for checking normality of independently and identically distributed observations based on the third derivative T 3 of the logarithm of the empirical moment-generating function is proposed. A significant departure of this function from the horizontal zero line is indicative of non-normality. Behaviour in the neighbourhood of 0 indicates the type of departure from the normal distribution. Examples show that the T 3 -method, when used in conjunction with the classical probability plot, can provide valuable insight into the data and be a powerful graphical tool.

Diameter and Basal Area Increment in Permanent Growth and Yield Plots in Switzerland

Abstract: The development trend of the diameter increment and the basal area increment of single trees and of stands is examined by means of 25 permanent trial plots of the growth and yield research. A number of these plots have been periodically measured for more than 100 years. The plots are not systematically distributed over Switzerland. The periodic resolution of the measurements lies between 4 and 10 years. In the study, the diameter increment is used for single trees and tree classes, the basal area increment for stands. These two quantities are preferred over other quantities such as height and volume because of their simple and reliable measurability. The assessment of a possible trend is done by means of a comparison of the growth with either the mean of the whole observation period, or, in those cases where it is permissible, with yield tables. Despite increasing age, a constant or, as is the case in the most recent observation period, an increase of the diameter and basal area increment can be shown for various tree species and for various forest structures in different areas of Switzerland. Relationships between the observed basal area increment and the development of the climate parameters or the silvicultural treatment can be ascertained only in some cases. Apparently the site productivity has changed or is in the process of changing. On the basis of the available data, none of the possible hypotheses - climate change, change of the CO2, content in the air, influx of substances, extension of silvicultural management etc. - can be either accepted or rejected.

Detection of genetic variation between Ophiostoma ulmi and the NAN and EAN races of O. novo-ulmi in Switzerland using RAPD markers.

Abstract: Summary The structure of the Ophiostoma ulmi and Ophiostoma novo-ulmi population of Switzerland was analysed. 79 Swiss isolates were compared to reference strains from various countries. A dendrogram from RAPD profiles was produced. O. ulmi and O. novo-ulmi were clearly separated into two major clusters. O. novo-ulmi was further divided into the EAN and NAN races. This classification is consistent with subgroups by taxonomic parameters (growth rate, culture aspect, fertility barriers). The variation detected within the EAN and NAN races indicates a post-epidemic situation in Switzerland. A clonal population is present only in a restricted area in mid-eastern Switzerland, indicating a still active disease front.

The importance of sorediate crustose lichens in the epiphytic lichen flora of the swiss plateau and the pre-alps

Abstract: Standardized lichen surveys were conducted on 849 trees in 132 ecological long-term observation plots in the Swiss Plateau and Pre-Alps: 262 lichen taxa were identified, 64 (24%) of them sorediate crustose species. Their mean percentage of the flora on individual trees and in individual plots was even higher. The mean percentage of crustose lichen species with vegetative propagules, such as soredia, was per plot significantly higher in the Pre-Alps than in the Plateau, higher in forest than in non-forest areas, and, according to the vegetation belts, lowest in the colline-submontane zone. It was found that the biodiversity of lichens could not be determined without considering the sorediate crustose lichens. Furthermore, by performing standardized surveys of all taxa, the occurrence of the following species in Switzerland was confirmed for the first time:Cliostomum leprosum,Fuscidea arboricola,Fuscidea pusilla,Hypocenomyce leucococca,Hypocenomyce sorophora,Lecanora norvegica,Lepraria eburnea,Lepraria elobata,Lepraria jackii,Lepraria obtusatica,Lepraria rigidula,Pertusaria borealisandRinodina griseosoralifera. Seven taxa that displayed distinctive chemistry, could not yet be identified. 1996 The British Lichen Society

Transition Metals in Llano Vermiculite Samples: an EPR Study

Abstract: Continuous wave and pulsed electron paramagnetic resonance spectroscopies combined with thermal and chemical methods were used to identify and characterize V(IV), Fe(III), Mn(II) and Cr(III) in a multimineral system that consists of vermiculite and impurities of carbonates. All of these transition metals were structure-bound in mineral phases. The V(IV) was located in octahedral layers of the vermiculite and became oxidized to V(V) during the transformation of the host mineral to enstatite at about 800 °C. The Fe(III) was associated with the vermiculite as well as the carbonate impurities. The Fe(III) identified in the vermiculite was transferred into the enstatite structure during the thermal conversion. An indirect proof of Fe(III) and Cr(III) in the impurities was found in the heated samples in which these cations occurred in Ca and/or Mg oxides that were formed by transformation of the carbonates. The Mn(II) in the untreated samples was associated with the impurities and was also detected in oxides formed from the samples heated at 600 °C.

Growth Trends of Swiss Forests: Tree-Ring Data. Case Study Toppwald

Abstract: In cooperation with other colleagues, concerted research on recent growth trends based on data from tree analyses, permanent plots and from forest inventories was undertaken. This study is based on tree growth analysis of spruce and fir on the permanent plot Toppwald and the trees are compared to earlier sampled trees of the Swiss Sanasilva 1984 study. Climate models are used to detect known influences of weather patterns and climate change; these effects explain 9 to 37% of the growth variance. In the calculated, non-climatic residual data, a long-term time-dependent trend of 4 to 49% of the growth variance was found. This shows that growth of the two species has improved since the beginning of the century. In the most recent period the residuals show, for most cases, an increased growth since 1980. Analysis of the whole time series reveals neither an exceptional rise nor any growth levels which have not been seen or reached earlier in this century.

Response of European Chestnut to Varying Calcium/Aluminum Ratios

Abstract: The response of European chestnut (Castanea sativa Mill.) to varying Ca/Al ratios of 10,1,0.1, and control (no Al added) in nutrient solutions with constant concentrations of 1 mmol L -1 Ca was investigated in a greenhouse experiment. The various Ca/Al ratios did not cause a significant effect on biomasses of roots, stems, shoots, and total plants. At a Ca/Al ratio of 0.1, however, a lower number of leaves with lengths >15 cm, a decreased biomass of leaves, an increased root/shoot ratio, and a decreased fine root ratio (roots with diameters <1 mm/ root with diameters 1-2 mm) were observed. Elemental analyses of At and base nutrient cations in roots and leaves revealed that increased Al concentrations reduced the uptake of Ca and Mg, but not the uptake of K. Aluminum concentrations were much higher in fine roots than in leaves, clearly indicating that only a minor amount of root At was transported into leaves. This finding was supported by EDX analyses and microscopic data, where At in fine roots was mainly detected in epidermal and cortical cells, but to a lesser extent in cells of the stele. The comparison of the results from the greenhouse experiment with field data from southern Switzerland suggests that there is no current risk originating from low Ca/Al ratio in the soil solution for European chestnut at the field site.

Runoff processes in catchments with a small scale topography

Abstract: How do runoff processes influence nitrogen export from forested catchments? To support nitrogen balance studies for three experimental catchments (1500m2) in the Northern Swiss prealps water flow processes in the two dominating soil types are monitored. Here we present the results for an experimental wetland catchment (1500m2) and for a delineated sloped soil plot (10m2), both with a muck humus topsoil. Runoff measurements on both the catchment and the soil plot showed fast reactions of surface and subsurface runoff to rainfall inputs, indicating the dominance of fast-flow paths such as cracks and fissures. Three quarters of the runoff from the soil plot can be attributed to water flow in the gleyic, clayey subsoil, 20% to flow in the humic A horizon and only 5% to surface runoff. The water balance for the wetland catchment was closed. The water balance of the soil plot did not close. Due to vertical upward flow from the saturated subsoil into the upper layers, the surface runoff plus subsurface runoff exceeded the input (precipitation) to the plot.

Phytotoxic effects of the high molecular weight fraction of an aqueous leaf litter extract on barley root development

Abstract: The root development of barley seedlings grown for one week in an aerated nutrient solution was studied in the presence of dissolved organic matter from an aqueous chestnut leaf litter extract. In particular, the different effects of low and high molecular weight fractions (small molecules: molecular weight 10,000) of the leaf litter extract were examined. In the presence of large molecules root growth was inhibited, an irregular root tip morphology was observed, and Ca and Mg concentrations in the shoots were lower than in control plants. These phytotoxic effects were not caused by the formation of an impermeable layer of large molecules on the root surfaces that lower accessibility for nutrient cations as inferred from voltammetric experiments. A germination assay using spruce seeds, however, indicated allelochemical effects of large molecules, which exhibit a higher aromaticity than the small molecules as indicated by spectroscopic characterisation. In the growth experiments with small molecules, no influence on the root development of barley was evident, but an increase of Ca and Mg in the shoots was detected. During these growth experiments, a large amount of the small molecules, mainly simple phenols and amino acids, disappeared from the nutrient solution. The loss of small molecules was most likely the effect of mineralisation.

Dendrochronologie —ein jahrgenauer Maßstab zur Entschlüsselung der Umwelt-und Menschheitsgeschichte

Abstract: Over the past 20 years dendrochronology has developed into one of the most important methods for the reconstruction and dating of past events. Archeologists and historians use it for dating wooden artifacts, buildings, and settlements. Treering sequences also allow the reconstruction of geomorphological and climatological processes. Dendrochronologists attempt to answer the question of whether anthropogenic deposition from the past 200 years is already affecting tree growth and climate globally. F ragen der heutigen Zeit bestimmen die Thematik der jahrringanalytischen Forschung. Aus technischer Sicht ist der Begriff Prfizision ein magisches Wort der modernen westlichen Gesellschaft. Es ist abet auch die Grundlage der Dendrochronologie; jahrgenau wird jeder Jahrring mit dem Oberbrackungsverfahren des Crossdating datiert. Aus politischer Sicht sind es die Schlagw~Srter Umwelt, Dynamik und Produktion. Die Begriffe korrespondieren mit den Hauptzielen der Dendrochronologie, die die Ver~nderungen der Umwelt durch den Menschen und die Produktionskraft der W~tlder untersucht. Die meisten Bfiume in Gebieten mit saisonalem Klima bilden Jahrringe aus. In den Hochgebirgen, den n0rdlichen NadelwNdern und den Mischw~ldern in allen gem~13igten Zonen der Erde wird den B~umen eine Wachstumsunterbrechung durch tiefe Temperaturen im Winter, in Wasten und Savannen dutch Trockenheit im Sommer aufgedr~tngt. Die saisonal unterschiedlichen Wachstumsbedingungen kommen in der Gestalt der Jahrringe zum Ausdruck; zu Beginn der Wachstumsperiode entsteht lockeres Frahholz, am Ende dichtes Spfitholz [1]. In tropischen Gebieten reagieren nur einzelne Baumarten auf die relativ geringen saisonalen Veranderungen mit der Bildung von Jahrringen. Ein klassisches Beispiel ist Tabebuia barbata in den Oberschwemmungswfildern im ~tquatorialen S~idamerika. Diese Baume aus der Familie tier Bignoniaceae bilden trotz eines mehr oder weniger gleichfOrmigen Klimas deutliche Jahrringe aus, denn Sauerstoffarmut im Wurzelbereich fahrt w~thrend der mehrmonatigen Oberflutungsperiode zu einer Wachstumsunterbrechung [2]. In jedem Individuum ist die Gestalt des Jahrrings Ausdruck genetischer Konstitution und lokaler Umweltverhfiltnisse. Mechanische Strel3faktoren bestimmen weitgehend die Verteilung von unterschiedlich zugund druckfesten Elementen. Deshalb sind Jahrringe in Asten, St~tmmen und Wurzeln verschieden aufgebaut. Zusfitzlich beeinflussen Okologische

A Comparison of Analytical Approaches for Detecting Diameter Growth Trends: Case Studies from Switzerland

Abstract: Growth patterns in forests can be monitored using three approaches: assessments on permanent growth and yield plots, tree ring and stem analyses and forest inventories. Each of the three approaches has distinct advantages and disadvantages. To evaluate the effects of the three approaches on the detection and description of growth trends, they are applied to three identical areas: Switzerland, the Toppwald region in the Canton of Berne and the selection forests in the Toppwald region. The results of the case studies are discussed and the specific contribution of each approach for monitoring forest growth is highlighted. The data presented show a clear increase in growth rates in the last decades. However, these growth rates cannot be related to site productivity alone; confounding factors are very likely.

Growth Patterns in Forests of the Canton of Berne, Switzerland, Based on Inventory Data

Abstract: Monitoring forest condition and changes over time has a long tradition in Switzerland. The idea of describing stand development on the basis of permanent observa- tions emerged during the last century. Gurnaud (1878), working in France, elaborated rules for the application of repeated measurements in estimating increment; this procedure is known as the control method. These rules were first applied in Switzerland by Biolley in 1890 to the forest of Couvet in the Jura (Biolley 1921; Kurt, 1987). Schrnid (1963, 1967) combined the techniques of continuous forest inventory (CFI) with the control method to establish an inventory system which has now been implemented in many Swiss cantons. Control sampling is based on permanent plots; increment is determined by comparing data taken from successive inventories. In this study, data will be used that have been assessed in forest management planning inventories in the canton of Berne. We are grateful to the Bernese Forest Service, especially to Dr. J. Grilc, who generously made the data for this study available. The findings of this study will be complemented by the reports of Zingg and Braker (in this volume), who worked with data from permanent growth and yield plots and with tree ring data.

Automated Recognition of Forest Patterns using Aerial Photographs

Abstract: Keywords: Vision Reference LPM-CONF-1996-004View record in Web of Science Record created on 2006-06-22, modified on 2016-08-08