Mitteilung von Beobachtungen bei Untersuchungen über die Einwirkung der neuen Kontaktinsektizide auf Wachsmotten und Seidenraupen     

Dr. Walter Bröker 《Journal of pest science》1953,26(6):88-89

Ohne Zusammenfassung  相似文献   

Die Johannisbrotmotte,Myelois ceratoniae Zell. als Schädling an Apfelsinen     

Dr. Walter Steinhausen 《Journal of pest science》1953,26(11):172-172

Ohne Zusammenfassung  相似文献   

A new ent-kaurane diterpenoid from Croton tonkinensis leaves     

Minh PT  Ngoc PH  Taylor WC  Cuong NM 《Fitoterapia》2004,75(6):552-556

A new ent-kaurane diterpenoid (1) was isolated from the leaves of Croton tonkinensis. The structure of 1 was determined as ent-7beta-hydroxy-15-oxokaur-16-en-18-ol from spectroscopic methods.  相似文献   

Farmers participation and socio-economic effects of a watershed management programme in Central Java (Solo river basin,Wiroko watershed)     

Rumpoko Dewo Daru  Walter E. J. Tips 《Agroforestry Systems》1985,3(2):159-180

A self-help watershed management project in the densely populated areas of Central Java, Indonesia, is discussed in terms of its achievements to combine activities to improve the physical, the social and the economic environment. Without simultaneous, well-planned action on these three essential components the project's improvements cannot be sustained by the farmers. It was found that activities such as tree planting and maintenance, construction of soil erosion control structures and training in agroforestry-type intensification techniques for land cultivation serve as a focus to induce farmers to participate. Participation can be sustained in spite of initial decreasing net income if increases in land productivity based on agroforestry practices together with appropriate training programmes organize and motivate the farmers. In future watershed management programmes more emphasis may be placed on the rural development planning aspects of e.g. agroforestry techniques, and on rural community organization.This paper is based on a M.Sc. research study conducted by the first author under the supervision of the second author at the Rural Development Planning Programme of the Division of Human Settlements Development, A.I.T., Bangkok. The first author is indebted to FAO and the Canadian International Development Agency for scholarship and research grants and to his employer, the Solo Watershed Development Centre of the Indonesian Government. The second author acknowledges his secondment by the Belgian Development Co-operation Administration, Brussels. Comments of the research committee members, Prof. Dr. H. Dias and J. Piper on the research project and of anonymous referees on the paper are gratefully acknowledged. However, the responsibility for the views presented here lies solely with the authors.  相似文献   

Rattenschäden anPinus radiata in Chile     

Walter Rühm 《Journal of pest science》1966,39(5):69-71

Zusammenfassung Es wird von Fraßbeschädigungen an derPinus radiata Don. durchRattus rattus L. aus der nördlichen Forstregion Chiles berichtet. Stark beschädigte Kiefern mit mehreren Fraßstellen oder einer fast vollständigen Ringelung starben durch Vertrocknen ab. Bei weitgehender Ringelung kam es nicht selten infolge eines Staues der Assimilate oberhalb der Beschädigungen zu einem abnormen Dickenwachstum. Diese verformten Bäume wurden häufig vom Wind gebrochen oder geworfen. Der starke Befall führte in einem Waldgebiet zum frühzeitigen Abtrieb eines Bestandes von zirka 150 ha und zu einer starken Durchforstung angrenzender Bestände in erosionsgefährdeter Hanglage. Nach dreijähriger Dauer ließ der Fraß plötzlich wieder nach. Die Massenvermehrung der Ratten stand in keinem direkten Zusammenhang zurPinus radiata. Durch die besondere Form der Bewirtschaftung und die daraus resultierende mangelnde Pflege derPinus radiata wurde der Angriff der Ratten begünstigt.

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Summary Damages are described which were caused byRattus rattus L. inPinus radiata Don. forests in the northern forest districts of Chile. Heavily damaged ones, some of them completely ringbarked, died. Partly ringbarked trees frequently showed an abnormal increase in size above the lesion (assimilation). Such crippled trees were frequently broken or roote by the wind. In one instant an area of 150 ha had to be cleared, and the adjacent areas were thinned. Thus, the slopes were exposed to erosion. The chewing by the rodents suddenly diminished after three years from onset. The tremendous reproduction rate of the rats was not related to thePinus radiata habitat. Lack of proficient management favored the rats.

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竹材结构的防腐   总被引：2，自引：0，他引：2  

Prof. Dr. Walter Liese 《世界竹藤通讯》2005,3(2):16-21

由于在露天环境中遭遇生物腐蚀,竹秆的持久性差,所以需要采取化学手段增强其耐力.但是它的解剖构造使化学物质难以像木材那样容易进入竹材.竹秆的外部由其表皮保护防水,不像木材那样有径向渗透的途径.而其内部腔隙也有保护性纤维.化学物质的主要渗透途径位于竹秆根部微管束的后生木质部.这些渗透途径分布于横剖面,很不均匀,且少,只占总面积的8～10%,而且在通过竹节时改变方向.由于在采伐时砍伤竹秆,通向导管的细胞腔被堵塞,渗透途径也受影响.周围的薄壁细胞是竹秆组织的主要部分,它们通过微小的纹孔互相连接,只能通过弥散进入.它们所含的淀粉是昆虫和某些真菌的食品.对纤维的保护也有赖于弥散.用化学物质进行保护,对于新鲜的含水量高的竹秆效果最好.就像简单的根部处理,或技术性较强的细胞液改善.新鲜竹秆的薄壁组织和纤维也能通过垂直弥散的方法得到保护.如进行滴渍和浸渍工作,最好在竹材含水分时劈开,因为薄壁组织容易接受弥散.技术措施如竹秆的水分储存和熏蒸的过程,与竹秆的自然结构,尤其是薄壁组织有关.  相似文献   

Über einen Zusammenbruch der Gelbhalsmauspopulation im Nationalpark Bayerischer Wald     

Walter Bäumler 《Journal of pest science》1973,46(11):161-168

Zusammenfassung Der Energiesto? eines guten Samenjahres der Fichte im Nationalpark Bayerischer Wald bewirkte bei M?usen im Frühjahr 1972 zun?chst eine starke Zunahme der Gelbhalsmaus. Nach dem Zusammenbruch dieser Population unter Stresserscheinungen, hervorgerufen durch Nahrungsverknappung und überbev?lkerung, trat im Herbst die R?telmaus st?rker in Erscheinung, die insbesondere an Laubh?lzern im Winter 1972/73 deutliche Spuren hinterlie?. Im Frühjahr 1973 dominierte nach einem schneereichen Winter bei sehr geringer Dichte die Erdmaus. Untersuchungen über die Nahrungswahl, Energie- reserven, Reproduktionsrate und Stresserscheinungen zeigten, da? die Populationsentwicklung der Gelbhalsmaus vorwiegend durch das Nahrungsangebot gesteuert wurde. Die Bev?lkerungsentwicklung der R?telmaus erschien dagegen von der Gelbhalsmaus negativ beeinflu?t oder durch nicht aufgedeckte endogene Faktoren geregelt. Es ergaben sich hier keine Hinweise für das Vorhandensein von Stressoren in der entscheidenden Vermehrungspause bis zum August 1972. Eine starke Zunahme der Adrenal- gewichte wurde erst im November bei h?chster Dichte und dem Einsetzen des Winters beobachtet.

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Summary Studies about a turnover of a Field-Mouse-population in the Bavarian National Park. In 1972 and 73 research work was carried out about population dynamics of the three most commonly species of rodents in the Bavarian National Park near the czech border: The Yellownecked Field Mouse (Apodemus flavicollis L.), the Bank Vole (Clethrionomys glareolus) and the Common Vole (Microtus agrestis L.). A great amount of spruce- seeds seemed to be most important for increased numbers of the Field Mouse trapped in the spring 1972 on all five localities (A, B, C, D and E) which were observed (Abb. 1). After the crash of this population in August 1972 by good weather conditions (Abb. 2) numbers of the Bank Vole were increased and this species was now most numerous in all localities (Abb. 1). In June 1973 the lowest density of all species was observed and the Common Vole dominated. This latter fact may be related to the high snow-cover until May 1973. Studies about ingested food-stuffs, body-fat content (Tab. 1) reproduction-rate (Abb. 3) and signs of stress (Abb. 4) showed, that the crash of the Field Mouse was caused primarly by detioration of food coupled with crowding effects. The population dynamics of the Bank Vole seemed interfered by the Field Mouse. No signs of stress were however detected during the recess of reproduction until August 1972 when the Field Mouse was dominating.

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Reinvestigation of the proteolytically active components of Bromelia pinguin fruit     

Payrol JA  Obregón WD  Natalucci CL  Caffini NO 《Fitoterapia》2005,76(6):540-548

Pinguinain is the name given to a proteolytic enzyme preparation obtained from Bromelia pinguin fruits that has been scarcely studied. The present paper deals on the reexamination of the proteases present in fruits of B. pinguin grown in Cienfuegos, Cuba. The preparation (partially purified pinguinain, PPP) showed the main characteristics of the cysteine proteases, i.e., optimum pH within alkaline range (pH 7.2-8.8), inhibition of proteolytic activity by thiol blocking reagents, which is usually reverted by addition of cysteine, a remarkable thermal stability and notable stability at high ionic strength values. Isoelectric focusing and zymogram of PPP revealed the presence of several proteolytic components between pI 4.6 and 8.1. Preliminary peptidase purification by cationic exchange chromatography showed the presence of two main proteolytic fractions with molecular masses of approximately 20.0 kDa, according to SDS-PAGE.  相似文献   

Signals of summer drought in crown condition data from the German Level I network     

Walter Seidling 《European Journal of Forest Research》2007,126(4):529-544

Crown transparency estimates of Scots pine, Norway spruce, common beech, pedunculate and sessile oak, annually surveyed between 1990 and 2004 within a grid over Germany, provide a suitable response variable to study drought effects on forest trees. Major climatic factors, available on a monthly basis as plot-specifically interpolated values and parameters of site and stand conditions, biotic and other relevant factors were used as predictors in different cross- and length-sectional, and longitudinal models. Stand age is a considerable and most constant driver of crown transparency in all species. Pine, spruce and beech responded—mainly with a delay of 1 year—with some foliar loss in areas where there was a surplus of temperature after the generally hot and dry summer of 2003. Parallel time-series analyses delivered species-specific geographic large-scale patterns with delayed or recent precipitation deficits or temperature surpluses. Even if beech is partly responding in current years with leaf loss towards precipitation surpluses, defoliation is especially high 1 year after hot summers, partly a result of high seed sets after such summers. Crown condition of oak responds in dry and warm areas according to the drought stress hypothesis, however, in cool and wet mountainous ranges oak responds after wet summers with higher defoliation. Longitudinal approaches revealed for all 4-tree species significant relationships between crown condition and deviations from the long-term means of temperature, precipitation but also global radiation and wind speed. Results do not always match the drought stress hypothesis, however, this is not to expect considering the heterogeneous site, stand and climatic conditions across Germany. Complex interactions of climatic and biotic factors also impede simple relationships. Soil-related clusters reveal higher sensitivity of spruce and beech towards climatic drought factors on more acid soils with thin humus layers. Also clusters constructed from plot-specific courses of defoliation reveal groups with rather closer relationships like a group of pine plots in the Oberpfalz, which seems to be especially sensitive to summer drought.  相似文献   

European forest accounting: general concepts and Austrian experiences     

Walter Sekot 《European Journal of Forest Research》2007,126(4):481-494

Within the European Union there exist three different frameworks for forest accounting at the national level. For purposes of the national accounts, the regulations of the European System of Integrated Economic Accounts (ESA) have to be observed. They require a distinction between forestry and logging and provide specific guidelines for the valuation of standing timber. In recognition of the special character of forests and forestry production, two satellite accounts are devoted to forestry: the Economic Accounts for Forestry (EAF) and the European Framework for Integrated Environmental and Economic Accounting for Forests (IEEAF). Although they were designed as complementary to the national accounts and refer to the same basic methodologies, the guidelines for forest accounting provided by the three manuals are not fully compatible. Just recently, a further integration and harmonization of the concepts for forest accounting has been proposed. Austria has implemented the valuation of the increment as an output of forestry as requested by ESA and produces the EAF tables on a regular basis. The possibilities for extending forest accounting to natural resource accounts for standing timber and the IEEAF have been investigated in terms of pilot studies. The Austrian experiences and results exemplify the problems and possible solutions associated with the adoption of the different European schemes. Data deficits and valuation issues restrict the significance of respective results to some degree, especially as regards forestry-specific extensions of the accounting schemes.  相似文献