Mortality of silver fir and Norway Spruce in the Western Alps — a semi-parametric approach combining size-dependent and growth-dependent mortality

Question

Tree mortality can be modeled using two complementary covariates, tree size and tree growth. Tree growth is an integrative measure of tree vitality while tree diameter is a good index of sensitivity to disturbances and can be considered as a proxy for tree age which may indicate senescence. Few mortality models integrate both covariates because classical model calibration requires large permanent plot data-sets which are rare. How then can we calibrate a multivariate mortality model including size and growth when permanent plots data are not available?

Location

To answer this question, we studied Abies alba and Picea abies mortality in the French Swiss and Italian Alps.

Method

Our study proposes an alternative semi-parametric method which includes a random sample of living and dead trees with diameter and growth measurements.

Results

We were able to calibrate a mortality model combining both size-dependent and growth-dependent mortality. We demonstrated that A. alba had a lower annual mortality rate (10%) than P. abies (18%) for low growth (< 0.2 mmyear^?1). We also demonstrated that for higher diameters (DBH ≥ 70 cm), P. abies had a higher mortality rate (0.45%) than A. alba (0.32%).

Conclusion

Our results are consistent with the mechanisms of colonization-competition trade-off and of successional niche theory which may explain the coexistence of these two species in the Alps. The method we developed should be useful for forecasting tree mortality and can improve the efficiency of forest dynamics models.     

对渭北地区集雨灌溉的思考-以富平县底店乡“窖灌农业”示范区为例

合理高效地利用雨水资源对西北干旱半干旱地区尤其是地表水缺乏地下水不易利用地区的经济发展具有十分重要的意义。基于此,我们在陕西省“窖灌农业”试验示范基地对蓄水设施的修筑、运行、维护及水质、雨水利用现状等进行了调研和考察,指出了其存在的问题、解决措施及进一步发展的思路,为该地及整个渭北地区雨水集流灌溉的进一步发展提供指导和参考。     

Über die Veränderungen der Sorptionseigenschaften von Wurzeln zweier Pflanzenarten während der Verrottung

Die Steigerung der naturalen Erträge unserer Kulturpflanzen ist gegenwärtig kein wissenschaftlicher Arbeitsgegenstand der produktionsorientierten landwirtschaftlichen Forschung. Es bestehen häufig Bedenken, daß mit einer zunehmenden Ertragshöhe unerwünschte Wirkungen auf die Umwelt verbunden sind.

An ausgewählten Beispielen wird dargelegt, daß es zum einen nicht möglich ist, aus der Ertragshöhe oder den Ertragssteigerungen pauschal auf negative Umweltwirkungen der ackerbaulichen Produktion zu schließen. Zudem wird diskutiert, welche Bedeutung die Steigerung der Erträge von Kulturpflanzen für die Sicherung der technologischen, aber auch der ökologischen Ansprüche hat.

Ein Rückgang der Forschungs‐ und Publikationsleistungen zu Anbauverfahren bzw. dem Ertragsmanagement wird für die letzten Jahre dargelegt und dessen Bedeutung für die wissenschaftlichen Arbeiten der landwirtschaftlichen Produktion erörtert.     

Gas chromatographic analysis of milk for deoxynivalenol and its metabolite DOM-1

A gas chromatographic method is described for the determination of deoxynivalenol (DON) and its metabolite DOM-1 in milk. Milk samples were extracted with ethyl acetate on a commercially available disposable extraction column, followed by hexane-acetonitrile partitioning. Final purification was accomplished on a reverse phase C-18 cartridge. The trimethylsilyl ether (TMS) derivatives of DON were prepared, chromatographed on an OV-17 column, and quantitated with an electron capture detector. Chromatography of the TMS derivatives of milk extracts was compared to that of the corresponding heptafluorobutyryl derivatives. The limit of detection using TMS derivatives was 1 ng/mL for both toxins with recoveries averaging 82% +/- 9% at 2.5 and 10 ng/mL milk for DON and 85% +/- 6% at 10 ng/mL for DOM-1.     

Prüfung vonAegilops-Arten auf Resistenz gegenPseudocercosporella herpotrichoides (Fron) Deighton

Zusammenfassung 490 Sippen von 21Aegilops-Arten wurden in den Jahren 1980 bis 1982 unter Freilandbedingungen mit künstlicher Infektion auf Resistenz gegenüber dem Erreger der Halmbruchkrankheit des Getreides,Pseudocercosporella herpotrichoides (Fron) Deighton geprüft. Außerdem erfolgte an ausgewählten Sippen die Prüfung der Jungpflanzenanfälligkeit im Phytotron. Unter denAegilops-Mustern erwiesen sich im Freiland 31 Herkünfte als resistent bzw. schwach anfällig. Im einzelnen handelte es sich um Vertreter der ArtenAe. ventricosa, Ae. triuncialis, Ae. kotschyi, Ae. bicornis, Ae. columnaris, Ae. lorentii, Ae. peregrina, Ae. geniculata, Ae. speltoides, Ae. crassa undAe. tauschii. Die im Jungpflanzenstadium geprüften 7 Sippen, 3 vonAe. ventricosa und je 1 vonAe. bicornis, Ae. kotschyi undAe. lorentii, waren ebenfalls resistent bzw. schwach anfällig.

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TestingAegilops species for their reaction toPseudocercosporella herpotrichoides (Fron) Deighton

Summary From 1980–1982 490 accessions out of 21Aegilops species were tested in a field trial with artificial infection regarding their resistance toPseudocercosporella herpotrichoides (Fron) Deighton in cereal crops. Simultaneously, selected accessions were checked for their susceptibility in the seedling stage under controlled conditions in the phytotrone. Among theAegilops samples 31 accessions proved to be resistant or only slightly susceptible. This refers toAe. ventricosa, Ae. triuncialis, Ae. kotschyi, Ae. bicornis, Ae. columnaris, Ae. lorentii, Ae. peregrina, Ae. geniculata, Ae. speltoides, Ae. crassa andAe. tauschii. The accessions checked in the seedling stage, i. e. 3 ofAe. ventricosa and 1 ofAe. bicornis, Ae. kotschyi andAe. lorentii, showed also resistance or only low susceptibility.

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Aegilops Pseudocercosporella herpotrichoides

1980–1982 . 490 21 Aegilops Pseudocercosporella herpotrichoides (Fron) Deighton. , . Aegilops 31 ; ¶rt; Ae. ventricosa, Ae. triuncialis, Ae. kotschyi, Ae. bicornis, Ae. columnaris, Ae. lorentii, Ae. peregrina, Ae. geniculata, Ae. speltoides, Ae. crassa, Ae. tauschii. , , Ae. ventricosa Ae. bicornis, Ae. kotschyi, Ae. lorentii .

     

The occurrence of equine arteritis virus in Australia

This paper reports the first isolation of equine arteritis virus (EAV) in Australia and serological evidence of exposure to EAV in Australian horses. Twelve Standardbred stallions imported from North America were found to shed EAV in semen. One hundred and seven stallions were tested for serum antibodies to EAV and 73% of Standardbred stallions tested were seropositive as compared to 8% of Thoroughbred stallions. Serum antibody was detected in 71% of Standardbred mares, 6% of Standardbred racehorses and 1% of Thoroughbred mares and racehorses. Examination of stored serums demonstrated that EAV had been present in Australia since at least 1975.     

Determinants of adolescents' soft drink consumption

OBJECTIVE: To identify determinants of adolescents' consumption of carbonated soft drinks (regular and diet), both of total consumption and of consumption at school. DESIGN/SETTING/SUBJECTS: Regular and diet soft drink consumption was measured by food frequency questions that were dichotomised. Several potential environmental and personal determinants of consumption were measured. A total of 2870 (participation rate: 85%) 9th and 10th graders, within 33 Norwegian schools, participated in the study. Multilevel logistic regression analyses were preformed for total soft drink consumption (twice a week or more vs. less) and for consumption at school (once a week or more vs. less). RESULTS: A total of 63% and 27% of the participants reported to drink respectively regular and diet soft drinks twice a week or more, and 24% and 8%, respectively, reported to drink soft drinks once a week or more at school. Preferences, accessibility, modelling and attitudes were the strongest determinants of both regular and diet soft drink consumption. In addition, gender, educational plans and dieting were related to both total soft drink consumption and consumption at school. Pupils with longer distance from school to shop and those in schools with rules concerning soft drink consumption tended to have lower odds of drinking both regular and diet soft drinks at school. CONCLUSION: This study shows that gender, educational plans, dieting, accessibility, modelling, attitudes and preferences all seem to be strong determinants of adolescents' soft drink consumption. Parents and the home environment appear as great potential intervention targets.     

Isopathic and pluralist homeopathic treatment of commercial broilers with experimentally induced colibacillosis

This study sought to determine the efficacy of isopathic and pluralist homeopathic treatment of colibacillosis in broiler chickens and thereby contribute to the evaluation of homeopathy in general. In each of two experiments three groups of broilers, infected intratracheally at 8 days of age with E. coli (O78:K80), were treated with different combinations of homeopathic remedies. Control groups and an infected, doxycyline-treated group were included. Experiments differed only in the dose of E. coli. Efficacy of treatment was evaluated based on the parameters mortality, body weight gain and colibacillosis lesions. In both experiments doxycyline prevented mortality and reduced E. coli lesions and stunting. None of the homeopathically treated groups differed significantly with respect to any of the parameters from the non-medicated, infected control group. It is concluded that the results of this study do not justify use of these homeopathic remedies for treatment of colibacillosis in broilers. Furthermore, no significant effects of this homeopathic treatment were established.