Die internationale arbeitsgemeinschaft für bodenfruchtbarkeit (IOSDV) in der internationalen bodenkundlichen union trauert um ihren vorsitzenden professor eduard von boguslawski     

Dr. Hans‐Richard Wegener 《Archives of Agronomy and Soil Science》2013,59(6):451-455

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A. Levakovi und Hans Muggenthaler 《Forstwissenschaftliches Centralblatt》1927,49(15):555-560

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Die freie Pirch auf dem Boofer Hart bei Memmingen     

Hans Eschenlohr 《Forstwissenschaftliches Centralblatt》1921,43(10):376-391

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Die Neugestaltung der Forstwissenschaft in der Ostmark im Geiste des Nationalsozialismus     

Hans Schwarz 《Forstwissenschaftliches Centralblatt》1938,60(16):522-524

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The Production and Some Properties of the Brown Pigment of Aeromonas Liquefaciens     

Kjell Aurstad  Hans Kolbein Dahle 《Acta veterinaria Scandinavica》1972,13(2):251

The optimum conditions for pigment production by Ae. liquefaciens was found to be 30 °C and aerobic incubation, and the properties of the pigment are shown to be similar to those of the synthetic dopa-melanin referred to. The enzyme phenol oxidase was demonstrated in the culture filtrates, but not in extracts of disintegrated cells. As precursors for the pigment production, which was shown to be strictly pH dependent, DL-tyrosine, DL-dopa and catechol were used with success, while numerous other amino acids failed. The significance of the pigment as a criterium for the identification of strains which are pathogenic to certain animals or fishes, is not known.  相似文献   

Forstmeteorologische Messungen in einem Eichenbestand     

Rudolf Geiger und Hans Amann 《Forstwissenschaftliches Centralblatt》1931,53(10):341-351

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Pflanzliche Insektizide IV*. Die insektizide Wirkung des ätherischen Öls aus dem Balsamkraut,Chrysanthemum balsamita L     

Hans Jürgen Bestmann  Beate Classen  Uwe Kobold  Otto Vostrowsky  Fred Klingaup 《Journal of pest science》1987,60(2):31-34

The essential oil ofChrysanthemum balsamita L. revealed insecticidal properties when tested againstM. dirhodum aphids. The insecticidal activity was attributed to the presence of pyrethrine I in the oil. By an appropriate testing procedure, the dependence of the activity upon the time of harvesting of the plants was determined. Furthermore, the insecticidal effect of the oil was compared with that of a commercially available pyrethrum preparation.  相似文献   

The carbon budget of an adult <Emphasis Type="Italic">Pinus cembra</Emphasis> tree at the alpine timberline in the Central Austrian Alps     

Gerhard?WieserEmail author  Thomas?Gigele  Hans?Pausch 《European Journal of Forest Research》2005,124(1):1-8

We investigated carbon (C) uptake and respiratory losses of an adult Pinus cembra tree at the alpine timberline throughout an entire year by means of an automated, multiplexing gas exchange system. These chamber measurements were then combined with biomass data for scaling up the C budget to the tree level. Integrated over an entire year, the cumulative C gain of the tree under study was 23.5 kg of C in 2002. The daily C balance was negative for 5 months and the estimated total wintertime respiratory losses were 9% of the amount of C fixed during the growing season. The total annual C loss of the tree consumed 55% of the annual net C gain and the remaining surplus was stored in new tissues (36%) and used for fine root growth (9%). Thus, the overall C budget of P. cembra at the upper timberline is balanced fairly well, although the C sink strength in fine roots is strongly limited owing to low root zone temperatures when compared to conifers at lower elevation sites.  相似文献   

Modeling spatial variability in the life-cycle costs of low-volume forest roads     

Jürg Andreas Stückelberger  Hans Rudolf Heinimann  Edouard Charles Burlet 《European Journal of Forest Research》2006,125(4):377-390

Cost estimation is probably the most decisive factor in the process of computer-aided, preliminary planning for low-volume road networks. However, the cost of construction is normally assumed to be route-independent for a specific project area, resulting in sub-optimal layouts. This is especially true for mountainous terrain and in areas with unstable subsoil. Here, we present a model for more accurately estimating spatial variability in road life-cycle costs, based on terrain surface properties as well as geological properties of the subsoil. This parametric model incorporates four structural components: embankment, retaining structures, pavement, and drainage and stream-crossing structures. It is linked to a geo-database that allows users to derive location-specific parameter values as input. In applying this model, we have demonstrated that variability in costs ranges widely for mountainous areas, with the most expensive construction being approximately five times greater there than on more favorable sites. This variability strongly affects the optimal layout of a road network. First, when location-specific slope gradients are considered, costs are reduced by about 17% from those calculated via currently available engineering practices; when both slope gradient and geotechnical formations are included, those costs are decreased by about 20%. Second, the length of the road network is increased by about 4% and 10% respectively, compared with current practices.  相似文献   

Das Prinzip des integrierten Pflanzenschutzes     

Hans Steiner 《Journal of pest science》1968,41(9):129-131

Zusammenfassung Nach einer neueren Definition der integrierten Sch?dlingsbek?mpfung werden die Voraussetzungen genannt, die zur praktischen Anwendung dieses Verfahrens notwendig sind. Die Feststellung und Benützung wirtschaftlicher Schadensschwellen ist dabei besonders wichtig. Ferner wird auf die Bedeutung der richtigen Wahl chemischer Pflanzenschutzmittel hingewiesen, solange selektive Pr?parate noch nicht entwickelt und biologische Bek?mpfungsverfahren noch nicht praxisreif sind. Nicht eine pl?tzliche Umstellung von der konventionellen zur integrierten Sch?dlingsbek?mpfung ist erstrebenswert, sondern ein schrittweises Vorgehen, das den jeweiligen M?glichkeiten angepa?t werden mu?. Damit k?nnen auch jetzt schon beachtliche Erfolge erzielt werden.

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Summary A new definition of the integrated control concept is given and the perequisites for practical application are mentioned. Knowledge and use of economic injury levels is of vital importance in this respect. Furthermore, the importance of the choice of pesticides to be used is stressed, as selective materials are not available yet, and purely biological control can not yet be applied in practice. A change from the conventional chemical pest control system into an integrated pest control system has to be realized step by step according to increasing knowledge and experience. With this integrated control system remarkable results have been obtained.

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Résumé Après avoir établi une définition de la lutte integrée, l'auteur indique les conditions à remplir pour l'application pratique de cette méthode. La détermination et l'emploi de seuils de tolérance économiques est particulièrement important. En outre l'importance du choix judicieux des produits antiparasitaires chimiques est soulignée, compte tenu du fait des produits sélectifs ne sont pas encore développés et des procédés de lutte biologique pas encore m?rs pour la pratique. Un changement rapide de la lutte conventionelle à la lutte integrée n'est pas désirable, mais plut?t une évolution progressive qui soit adapté au fur et à mesure aux possibilités du moment. Ainsi, des succés considérables peuvent déjà être obtenus à brève échéance.

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