Nochmals: Der Tebendigen Wahres Besicht     

Heinrich Wilhelm Weber 《Forstwissenschaftliches Centralblatt》1921,43(12):468-470

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Die Bliederung unferer Wiffenschaft in eine Productionslehre und eine Betriebslehre,ihre Belchichte und ihre fritische Würdigung     

Dr. Deinrich Wilhelm Weber 《European Journal of Forest Research》1921,43(8-9):281-289

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Was ist „Forstgeschichte“, und welche Stelle nimmt sie im System unsrer Wissenschaft ein?     

Heinrich Weber 《European Journal of Forest Research》1916,38(8-9):412-428

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Heinrich Wilhelm Weber 《Forstwissenschaftliches Centralblatt》1925,47(1):74-80

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Das neue Institut für Pflanzenkrankheiten der Landwirtschaftlichen Hochschule Bonn-Poppelsdorf     

Hermann Weber 《Journal of pest science》1928,4(2):22-23

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Weber 《Forstwissenschaftliches Centralblatt》1909,31(6):323-330

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Bemerkungen zu Otto von Bentheim's „Das Oberförstersystem in den deutschen Staatsforstverwaltungen“     

Professor Dr. Weber 《European Journal of Forest Research》1909,31(6):323-330

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Long-term effects of five ameliorants on a saline-sodic soil of South Africa     

P.C. Van Rooyen  H.W. Weber 《Geoderma》1977,19(3):213-225

The effects of five ameliorants for saline-sodic soil reclamation on certain chemical and physical soil properties over a four-year period of observation are reported. Of these ameliorants, three are conventionally used (gypsum, sulphur, manure); the other two are for this purpose either unusual (potassium sulphate) or relatively unknown (molasses meal). Results published in a previous paper demonstrated that molasses meal had a very rapid-acting favourable effect on most soil physical properties whilst soil chemical conditions remained essentially unchanged. The effect on physical properties was presumably due to soil aggregation by the polysaccharide component of molasses meal. As a follow-up this paper shows, however, that this aggregation does not last long; the rigidly arid climatic conditions under which this experiment was carried out apparently do not favour the preservation of structural bonds consisting of polysaccharide gums. Consequently, a gradual decline of structural conditions took place after the second year. Although initially not as effective as molasses meal, gypsum and sulphur retained their favourable influence on physical properties over a longer period. Potassium sulphate and farmyard manure provided virtually no benefits.  相似文献   

Spatial variability of common carp populations in relation to lake morphology and physicochemical parameters in the upper Midwest United States     

M. J. Weber  M. L. Brown  D. W. Willis 《Ecology of Freshwater Fish》2010,19(4):555-565

Weber MJ, Brown ML, Willis DW. Spatial variability of common carp populations in relation to lake morphology and physicochemical parameters in the upper Midwest United States.
Ecology of Freshwater Fish 2010: 19: 555–565. © 2010 John Wiley & Sons A/S Abstract – Common carp (Cyprinus carpio) is a widespread invasive species that is tolerant of a wide range of environmental conditions. Despite the circumpolar distribution of the species, limited information is available describing factors related to spatial variation in population characteristics. Eighty‐four lakes and impoundments in the upper Midwest United States were sampled to investigate the relationships of common carp relative abundance with size structure, condition and growth rates. We also investigated abiotic factors (lake morphology, physical solids and water quality) that may broadly influence common carp populations. Common carp size structure and condition were inversely related to relative abundance. Common carp relative abundance increased and size structure shifted to smaller individuals with increased lake depth, whereas lake surface area, watershed:surface area ratio and physical solids were also important in explaining common carp abundance and size structure. Common carp condition was best explained by water quality parameters and increased with metrics of lake productivity. We conclude that knowledge of factors associated with variation in common carp populations among lakes provides insights into the autecology and broad provisions for management of this generalist invasive species.  相似文献   

Prevalence of chronic wasting in Dutch dairy herds with a history of chronic health problems     

Weber MF  Verhoeff J 《Tijdschrift voor diergeneeskunde》2001,126(6):180-183

The prevalence of chronic wasting in cattle in March and April 2000 was studied on 218 dairy farms with a history of health problems accompanied by wasting, following reports in the media suggesting that chronic wasting was a substantial problem on Dutch dairy farms. A telephone call revealed that the health problems had resolved on 41 farms; 16 of these farms had culled all cattle. Two farmers refused co-operation. On the remaining 175 farms the animals were inspected and was completed a questionnaire. A high percentage of culling for of health reasons (on average 18.1% of young stock and adult cattle) and an increased mortality rate (4.8%) were reported on the farms visited. In only two of the 175 inspected herds, more than 20 percent of cattle were found showing signs of wasting. These two herds were identified as 'chronic wasting herds'. The prevalence of such herds was low in this study. Consequently, it is likely that there were very few 'chronic wasting herds' among the whole Dutch dairy population in March/April 2000.  相似文献