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.

Prevalence and Mental Health Correlates of Sleep Disruption Among Military Members Serving in a Combat Zone

Abstract: Sleep disruption is an emergent military health issue, but remarkably little is known of its prevalence or comorbidities in the combat zone. This study was designed to quantify the prevalence and mental health correlates of sleep disruption among military personnel serving within a ground combat zone during Operation Enduring Freedom. This was a large, cross-sectional survey of active duty and reserve U.S. Navy personnel (N = 3,175). Self-reported sleep measures included total hours of sleep per day, total hours of sleep required to feel well-rested, difficulty falling asleep, and difficulty staying asleep. The survey also measured mental health symptoms, including post-traumatic stress symptoms, anxiety, and depression. Participants reported an average of 5.9 hours of sleep per day despite requiring on average 6.8 hours to feel well rested. More than half (56%) were classified as sleep deficient, and 67% reported 6 or fewer hours of sleep per day. Adjusted for covariates, individuals endorsing s...

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.

Cryptopodzolic soils in Switzerland.

Abstract: Summary Cryptopodzolic Soils are characterized by a thick blackish-brown mineral horizon rich in organic matter, the dark colour of which masks the morphological characteristics of podzolization. Little is known about the specific site factors that lead to the formation of these soils. Four representative soil profiles from a typical toposequence between 1700 and 500 m above sea level in southern Switzerland, embracing Haplic Podzols, Humic Cambisols and Cryptopodzolic Soils, are described morphologically, chemically and physically. The Cryptopodzolic Soils in this region are characterized by weak to moderate A1 and Fe translocation, and by a uniform incorporation of organic matter deep into the soil. The most prominent feature is the exceptional stability of the soil organic matter with a maximum in the spodic horizon. All these characteristics can be explained by the unique combined effect of a mild, wet climate, an Fe- and Al-rich acid bedrock and a litter layer providing dissolved organic matter rich in polyphenolic substances with strong metal-binding properties.