Zur Geschichte der Forstschädlingsbekämpfung vom Flugzeuge aus

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Individual tree diameter increment model for managed even-aged stands of ponderosa pine throughout the western United States using a multilevel linear mixed effects model

A diameter increment model is developed and evaluated for individual trees of ponderosa pine throughout the species range in the United States using a multilevel linear mixed model. Stochastic variability is broken down among period, locale, plot, tree and within-tree components. Covariates acting at tree and stand level, as breast height diameter, density, site index, and competition indices are included in the model as fixed effects in order to explain residual variability. The data set used in this study came from long-term permanent research plots in even-aged, pure stands both planted and of natural origin. The data base consists of six levels-of-growing stock studies supplemented by initial spacing and other permanent-plot thinning studies for a total of 310 plots, 34,263 trees and 153,854 observations. Regression analysis is the preferred technique used in growth and yield modeling in forestry. We choose the mixed effects models instead of the regression analysis approach because it allows for proper treatment of error terms in a repeated measures analysis framework. Regional growth and yield models exist for ponderosa pine. However, data collection and analysis procedures differ. As a result, comparisons of growth responses that may be due to geographic variation of the species are not possible. Our goal is to present a single distance-independent diameter increment model applicable throughout the geographic range of ponderosa pine in the United States and by using only data from long-term permanent plots on sites capable of the productivity estimated by Meyer [Meyer, W.H., 1938. Yield of Even-Aged Stands of Ponderosa Pine. US Department of Agriculture Technical Bulletin 630].     

Future of the animal health industry at a time of food crisis

It is popular in some quarters to say that there is no food crisis; that there is food aplenty; and that the problem is one of distribution or other over-arching technical difficulty. To the starving, however, there is a food crisis; and it neither speaks well nor bodes well for humanity if we dismiss their plight so glibly. The United Nations has called for a large and rapid increase in food production. Veterinary parasitologists and industry leaders can contribute to the production of healthier livestock and the expansion of aquaculture, but enhanced production and better delivery of plant foods may provide faster relief. Although livestock farming is not the most energy-efficient way of producing food, meat will remain a significant component of the global diet for the foreseeable future. New measures for parasite control will be needed, and we must improve our methods of inventing them. They need not act directly against the parasite. In the distant future lie other threats to the inhabitants of planet Earth, and here we must acknowledge the cogency of the no-food-crisis argument. In the long term, the production of animal foods and animal feeds will be revamped in ways that depend on how (or whether) we solve the energy crisis, the environmental crisis, the increasingly dire regional population crises, and the current world financial crisis. Throughout the 20th century, the animal health industry had to adapt to industrialization and expansive agribusiness. It will have to adapt to even greater changes in the 21st century and beyond.     

Fortschritt in der Bekämpfung von Rapsschädlingen

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Soil invertebrates and the degradation of vanillin,cinnamic acid,and lignins

A range of 8–25% of fed cinnamic 2-[¹⁴C] acid and 9–14% of injected vanillin 5-[¹⁴C] were oxidised to ¹⁴CO₂ at 15 C over 7 and 6 days respectively in an isopod, Oiuscus asellus; a millipede, Pseudopolydesmus serratus; a slug, Deroceras reticulatum; a snail, Oxychilus draparnaldi; and an earthworm, Eisenia foetida. Approximately 2–10% of nonmetabolised and 13–48%, of metabolised vanillin were present in the animal tissues after 6 days. Correspondingly. 1–4% and 22–66% of these materials were found in egesta.A millipede (Oxidus gracilis), O. asellus. D. reticuluttum. O. draparnaldi, and E. foetida were found unable to degrade ring [¹⁴C]-, methoxy [¹⁴C]- and side chain [¹⁴C]-lignin to ¹⁴CO₂ over 10 days, thus providing very strong evidence that these invertebrates are incapable of degrading liginin.