Gremmeniella abietina,Phacidium infestans,and other causes of damage in alpine,young pine plantations in Norway     

F. Roll-Hansen  Helga Roll-Hansen  T. Skroppa 《Forest Pathology》1992,22(2):77-94

Field studies of damage and mortality were carried out through 16 years in six young plantations, mostly of Pinus contorta, but also P. sylvestris and P. sibirica. Differences between pine species, P. contorta provenances, sites, and soil treatments are reported and discussed, as are influences of environment, climatic conditions, snow cover, and nutrient deficiency. Gremmeniella abietina was by far the most important cause of mortality; there were great differences between the sites as to development and seriousness. Other important causes of mortality and damage were Phacidium infestans, elk (Alces alces L.), voles, and snow pressure.  相似文献   

Untersuchungen über die Ausbreitung von Nonnenfaltern durch Markierung mit Seltenen Erden     

Else Jahn  Helga Lippay  Norbert Weidinger  Gerhard Schwach 《Journal of pest science》1966,39(2):17-22

Zusammenfassung In der vorliegenden Arbeit werden Laborversuche zur Markierung von Nonnenraupen und Nonnenfaltern mit den Seltenen Erden Europium und Dysprosium behandelt, sowie Freilanduntersuchungen zum Studium der Ausbreitung mit Europium gekennzeichneter Nonnenfalter. Imagines, die mit Mengen von 1/Exemplar im Raupenstadium besprüht worden waren, erwiesen sich, ebenso wie im Vorjahr in derselben Weise behandelte Kiefernspinner, als deutlich markiert. Zur Kennzeichnung der Falter gelangten im Labor und im Freiland 10 Europium, im Labor auch 10 Dysprosium/Exemplar mittels Besprühung erfolgreich zur Anwendung. Die Ausbreitungsuntersuchungen ergaben einen Überflug markierter Falter auf eine Entfernung von 2 km.

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Summary The present paper describes laboratory experiments in marking nun-caterpillars and nun-moths with the rare earths Europium and Dysprosium, as well as field studies on the spread of nun-moths marked with Europium. Nun-moths, sprayed with quantities of 1/individual in the caterpillar stage, proved distinctly marked, and so did pine spinners(Dendrolimus pini) treated the same way past year. Marking of moths succeeded in both laboratory and field by spraying with 10 Europium, in the laboratory also with 10 Dysprosium per individual. Spreading studies revealed marked moths overflying distances of 2 kilometres.

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Résumé L'ouvrage présent traite d'essais en laboratoire sur le marquage de chenilles et de papillons de la Nonne(L. monacha) au moyen des terres rares Europium et Dysprosium, ainsi que de recherches au terrain sur l'expansion de papillons de cette espèce marqués d'Europium. Les images de la Nonne, ayant été aspérgées au stade larvaire d'une dose de 1 par individu, se sont avérées distinctement marquées, de même que les Bombyx du Pin traités de la même manière l'année passée. — Le marquage de papillons a été effectué avec succès au laboratoire et au terrain au moyen de 10 d'Europium — au laboratoire aussi de 10 de Dysprosium — par individu, appliqués par aspersion. Les recherches sur l'expansion ont révélé un survol de papillons marqués à une distance de 2 km.

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Für weitgehende Unterstützung der entomologischen Untersuchungen sei den Herren Dr. W. Schedl, Förster C. Holzschuh und Förster F. Stradner der forstlichen Bundesversuchsanstalt, der physikalischen Auswertung Herrn Ing. D. Koch, Reaktorzentrum Seibersdorf, herzlich gedankt. Besonderer Dank sei auch der Landesforstinspektion Niederösterreich, der Bezirksforstinspektion Waidhofen/Thaya und der Forstverwaltung von Fischen-Ankern für großzügige Hilfe bei der Durchführung der Freilanduntersuchungen ausgesprochen.  相似文献   

Soil carbon distribution and quality in a montane rangeland-forest mosaic in northern Utah     

Helga Van Miegroet  Janis L. Boettinger  Michelle A. Baker  Julia Nielsen  Dave Evans  Alex Stum 《Forest Ecology and Management》2005,220(1-3):284-299

Relatively little is known about soil organic carbon (SOC) dynamics in montane ecosystems of the semi-arid western U.S. or the stability of current SOC pools under future climate change scenarios. We measured the distribution and quality of SOC in a mosaic of rangeland-forest vegetation types that occurs under similar climatic conditions on non-calcareous soils at Utah State University's T.W. Daniel Experimental Forest in northern Utah: the forest types were aspen [Populus tremuloides] and conifer (mixture of fir [Abies lasiocarpa] and spruce [Picea engelmannii]); the rangeland types were sagebrush steppe [Artemisia tridentata], grass-forb meadow, and a meadow-conifer ecotone. Total SOC was calculated from OC concentrations, estimates of bulk density by texture and rock-free soil volume in five pedons. The SOC quality was expressed in terms of leaching potential and decomposability. Amount and aromaticity of water-soluble organic carbon (DOC) was determined by water extraction and specific ultra violet absorbance at 254 nm (SUVA) of leached DOC. Decomposability of SOC and DOC was derived from laboratory incubation of soil samples and water extracts, respectively.

Although there was little difference in total SOC between soils sampled under different vegetation types, vertical distribution, and quality of SOC appeared to be influenced by vegetation. Forest soils had a distinct O horizon and higher SOC concentration in near-surface mineral horizons that declined sharply with depth. Rangeland soils lacked O horizons and SOC concentration declined more gradually. Quality of SOC under rangelands was more uniform with depth and SOC was less soluble and less decomposable (i.e., more stable) than under forests. However, DOC in grass-forb meadow soils was less aromatic and more bioavailable, likely promoting C retention through cycling. The SOC in forest soils was notably more leachable and decomposable, especially near the soil surface, with stability increasing with soil depth. Across the entire dataset, there was a weak inverse relationship between the decomposability and the aromaticity of DOC. Our data indicate that despite similar SOC pools, vegetation type may affect SOC retention capacity under future climate projections by influencing potential SOC losses via leaching and decomposition.  相似文献   

The interaction among age,thermal acclimation and growth rate in determining muscle metabolic capacities and tissue masses in the threespine stickleback,Gasterosteus aculeatus     

Helga Guderley  Brigitte A. Lavoie  Nicole Dubois 《Fish physiology and biochemistry》1994,13(5):419-431

Thermal acclimation may directly modify muscle metabolic capacities, or may modify them indirectly via effects upon physiological processes such as growth, reproduction or senescence. To evaluate these interacting effects, we examined the influence of thermal acclimation and acclimatization upon muscle metabolic capacities and tissue masses in 1 + stickleback, Gasterosteus aculeatus, in which confounding interactions between temperature and senescense should be absent. Furthermore, we examined the influence of thermal acclimation upon individual growth rate, muscle enzyme levels and tissue masses in 2 + stickleback sampled at the beginning of their final reproductive season. For 1 + stickleback, cold acclimation more than doubles mitochondrial enzyme levels in the axial muscle. Thermal acclimation did not change the condition of 1 + stickleback at feeding levels which could not maintain the condition of 2+ stickleback. Compensatory metabolic responses to temperature were not apparent in field acclimatized 1 + stickleback. The growth rate of 2 + stickleback was markedly affected by temperature: warm-acclimated fish generally lost mass even at very high levels of feeding (up to 78 enchytraid worms per day) while cold-acclimated fish gained mass. This suggests that warm temperatures accelerate the senescence of 2 + stickleback. Generally, muscle enzyme activities increased with growth rate. In axial muscle, the relationships between CS activity and growth rate differed with acclimation temperature. Independent of the influence of growth rate, CS activities were consistently higher in cold- than warm-acclimated 2 + stickleback, suggesting compensatory increases of CS activity with cold acclimation. Corresponding author; This paper is dedicated to the memory of Gerry J. FitzGerald who passed away on March 14, 1994.  相似文献   

Does the aerobic capacity of fish muscle change with growth rates?     

Dany Pelletier  Helga Guderley  Jean-Denis Dutil 《Fish physiology and biochemistry》1993,12(2):83-93

To ascertain whether growth rate modifies the oxidative capacity of fish white muscle, we examined the effects of individual growth rate on the activities of four mitochondrial enzymes in white muscle of the fast growing Atlantic cod,Gadus morhua. Growth rates were individually monitored in cod held at three acclimation temperatures during experiments repeated in four seasons. The size dependence of citrate synthase (CS), cytochrome C oxidase (CCO) and β-hydroxyacyl CoA dehydrogenase (HOAD) activities was established using wild cod ranging from 115 to 17,350 g. Given their negative allometry, CS and CCO activities in the experimental cod were corrected to those expected for a 1.2 kg animal. HOAD activities did not change with size. The specific activities of CCO and CS were positively correlated with growth rate. However, for both enzymes, season explained more of the variability than growth rate or temperature. Season was the only factor to significantly affect the activity of HOAD, while temperature and season interacted to determine glutamate dehydrogenase activity. CS activity was positively correlated with the initial condition of the cod, which differed among the seasons. The other enzymes did not show this relationship. The independent changes of these enzymes suggest that mitochondria undergo qualitative modifications with changes in growth rate, season and size. Although growth rate and the activities of CCO and CS are positively correlated, the activity of the mitochondrial enzymes is more affected by size, physical condition and season.  相似文献   

Bioeconomy – an emerging meta-discourse affecting forest discourses?     

Helga Pülzl  Daniela Kleinschmit  Bas Arts 《Scandinavian Journal of Forest Research》2014,29(4):386-393

The term bioeconomy and closely related notions like bio-based economy or knowledge-based bioeconomy (KBBE) are increasingly used by scientists and politicians in the last years. It does therefore have the potential of becoming an influential global discourse. Its role is however so far unclear. The general assumption that guides this paper is that discourses, resulting ideas and arguments are generally said to have performative power. They shape actors' views, influence their behaviour, impact on their beliefs and interests and can cause institutional change in a given society. Thus, the aim of this paper is twofold: first, it aims to analyse whether the ideas used in a bioeconomy discourse differs from those in other global meta-discourses of the last decades affecting forest discourses, such as the ecological modernization discourse or the sustainable development discourse. Second, this paper aims to analyse whether and how the bioeconomy discourse has started (or not) to reshape or overshadow the “classical” forest discourses, such as sustainable forest management, forest biodiversity or forest and climate change.  相似文献   

Research Notes     

Helga E. Jacobson 《Asia Pacific viewpoint》1969,10(2):55-59

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Taxonomy and evolution of cultivated plants: Literature review 1980/1981     

Dr. Jürgen Schultze-Motel  Dr. Reinhard Fritsch  Dr. Karl Hammer  Dr. Peter Hanelt  Dr. Joachim Kruse  Dr. Helga I. Maass  Dr. Harald Ohle  Klaus Pistrick 《Genetic Resources and Crop Evolution》1982,30(2):273-291

Summary Important papers on taxonomy and evolution of cultivated plants published in 1980 and 1981 were compiled and briefly discussed.

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Taxonomie und Evolution der Kulturpflanzen: Literaturübersicht 1980/1981

Zusammenfassung Wichtige Arbeiten über Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1980 und 1981 wurden zusammengestellt und kurz kommentiert.

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: 1980–1981 .

, 1980 1981 . .

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Herrn Prof. Dr. Dr. h. c. mult. H.Stubbe aus Anlaß der 80. Wiederkehr seines Geburtstages gewidmet.  相似文献   

Taxonomy and evolution of cultivated plants: Literature review 1988/1989     

Jürgen Schultze-Motel  Reinhard Fritsch  Karl Hammer  Peter Hanelt  Joachim Kruse  Helga I. Maass  Harald Ohle  Klaus Pistrick 《Genetic Resources and Crop Evolution》1990,38(3):417-434

Summary Important papers on taxonomy and evolution of cultivated plants published in 1988 and 1989 were compiled and briefly discussed.

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Taxonomie und Evolution der Kulturpflanzen: Literaturübersicht 1988/1989

Zusammenfassung Wichtige Arbeiten über Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1988 und 1989 wurden zusammengestellt und kurz kommentiert.

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: 1988–1989

, 1988 1989 . .

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A guidance for the assessment and evaluation of sediment quality a German Approach based on ecotoxicological and chemical measurements     

Wolfgang Ahlf  Henner Hollert  Helga Neumann-Hensel  Mathias Ricking 《Journal of Soils and Sediments》2002,2(1):37-42

The recommendations presented in this paper use an integrated hierarchical approach combining toxicological, chemical and ecological information to assess and evaluate the quality of sediments. For this reason, biological methods, in combination with the tools of chemical analysis, are given priority when examining the quality of the sediment to establish adverse effects. The trigger is the biotest, instead of chemical methods commonly used. The individual methods are presented for a German approach and can be adopted to other countries by applying ISO, OECD methods. Support is provided on how to best integrate data generated using different assessment tools. Keywords: Bioassays; biological and chemical analysis; ecotoxicology; integrated assessment; sediment assessment; sediment quality; stepwise strategy  相似文献