A case study of forest management planning using a new heuristic algorithm     

Son JH  Vilcko F  Sánchez Orois S  Kunth S  Son YM  von Gadow K 《Tree physiology》2005,25(7):929-938

We present an approach to generate and evaluate different silvicultural development paths and to optimize the development of a Norway spruce stand, using a long-term planning horizon. To generate a silvicultural path, the maximum stand density was applied. At each thinning event, three possible thinning intensities (10, 20, 30% of the stem number per ha) were randomly chosen. A search algorithm known as modified Accelerated Simulated Annealing (mASA) was used to estimate the optimum combination of stand paths for a given forest as a whole. Production and economic management objectives were considered and then compared. The economic criterion was the Expected Stand Value (ESV) with a 4% discount rate. The generated data set of 38 Norway spruce stands (comprising a total of 123.8 ha) was used in the case study. The result with the best combination of paths was presented in a digitized forest map. Forest management simulation was performed using a specially developed computer program, for a planning horizon of 20 years. The mASA proved to be an effective search method for identifying optimum paths.  相似文献   

III. Buchbesprechungen     

von Pechmann  Attenberger  E. Rohmeder  Backmund und H. Mayer 《Forstwissenschaftliches Centralblatt》1955,74(5-6):186-192

Ohne Zusammenfassung  相似文献   

Using model scenarios to predict and evaluate forest-management impacts on soil base saturation at landscape level     

Dietmar?Zirlewagen  Klaus?von?WilpertEmail author 《European Journal of Forest Research》2004,123(4):269-282

Silviculture, forest conversion and technical tools of ecosystem management, such as forest liming, display their effects at the landscape level. Therefore their planning and control should take place at the same scale. The primary objective of this work was to assess soil chemical properties and their changes in relationship to ecosystem management, especially forest conversion and forest liming. We calculated scenario models, based on regression analysis, which allow such an examination in the context of understanding landscape processes which can be expected to operate in the sampling region. Stepwise multiple linear regression analysis was used to predict soil chemical attributes (base saturation, pH, C/N content and stock, exchangeable stocks of Ca and Mg) as indicators of site stability or off-site effects of forest ecosystems such as effects on clean drinking water from forested watersheds. Because of space limitations, in this paper only the modelling results of base saturation are presented. Base saturation was used as an integrative example for other soil chemical properties. The transformation of measurements to the regional scale, i.e., the regionalization, was calculated for the forested parts of two test regions in the Black Forest on the basis of measured chemical properties of 90–150 soil profiles per test region. The models have a spatial resolution of 50×50 m, which is a spatial scale relevant for forestry practice and forest management. Topographic variables (e.g., elevation, aspect, slope gradient, and slope length), the stratigraphic classification of the geologic substrate, stand characteristics from forest inventory data, and finally technical information about forest liming were the auxiliary variables (secondary site properties) that provided indirect information about base saturation and were available for the whole forested area of the test regions. Base saturation could be predicted with an accuracy of ~50–70% (in terms of the multiple R²) by using these properties as predictor variables in multiple linear regression analyses. The explained proportion of variance was unexpectedly high considering the high geomorphological heterogeneity of the two test regions. Based upon the regionalization models, it was possible to establish scenarios showing the landscape-related effects on base saturation that may be achieved by forest conversion towards a higher proportion of forests with broad-leaved mixed stands and by forest liming. These scenarios allow the interactions between several influencing factors and management strategies and the impacts on the target variable to be synoptically judged. Thus the presented regionalization models achieve the role of decision support tools for the planning of forest management at the landscape level. They allow an assessment of the environmental effects of forest management strategies in terms of site sustainability or preservation of water resources in forested catchments.  相似文献   

Jahrringchronologie der Spessart-Buchen     

W. von Jazewitsch 《Forstwissenschaftliches Centralblatt》1953,72(7-8):234-247

Ohne ZusammenfassungHerrn Prof. Dr. O.Renner zum 70. Geburtstag gewidmet.Mit 6 Abbildungen  相似文献   

Productivity of poplar short rotation coppice in an alley-cropping agroforestry system     

Justine Lamerre  Kai-Uwe Schwarz  Maren Langhof  Georg von Wühlisch  Jörg-Michael Greef 《Agroforestry Systems》2015,89(5):933-942

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Long‐Term Functional Outcome of Tibial Plateau Leveling Osteotomy Versus Extracapsular Repair in a Heterogeneous Population of Dog          下载免费PDF全文

Dirsko von Pfeil  Mike Edwards  Samantha Nelson  Ursula Krotscheck 《Veterinary surgery : VS》2015,44(7):920-920

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Veterinary Clinical Pathology goes online‐only beginning in January 2016          下载免费PDF全文

Meredith Duey  Dr. Barbara von Beust 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2015,44(4):473-473

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Nonthymoma‐associated exfoliative dermatitis in 18 cats          下载免费PDF全文

Monika Linek  Silvia Rüfenacht  Chiara Brachelente  Claudia von Tscharner  Claude Favrot  Sylvia Wilhelm  Claudia Nett  Ralf S. Mueller  Ursula Mayer  Monika Welle 《Veterinary dermatology》2015,26(1):40-e13

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Acute renal failure associated with Amaranthus species ingestion by lambs          下载免费PDF全文

AE Kessell  J Boulton  GL Krebs  JC Quinn 《Australian veterinary journal》2015,93(6):208-213

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Detection of ruminant meat and bone meals in animal feed by real-time polymerase chain reaction: result of an interlaboratory study   总被引：1，自引：0，他引：1  

Prado M  Berben G  Fumière O  van Duijn G  Mensinga-Kruize J  Reaney S  Boix A  von Holst C 《Journal of agricultural and food chemistry》2007,55(18):7495-7501

The commercialization of animal feeds infected by prions proved to be the main cause of transmission of bovine spongiform encephalopathy (BSE). Therefore, feed bans were enforced, initially for ruminant feeds, and later for all feeds for farmed animals. The development and validation of analytical methods for the species-specific detection of animal proteins in animal feed has been indicated in the TSE (Transmissible Spongiform Encephalopathies) Roadmap (European Commission. The TSE (Transmissible Spongiform Encephalopathy) roadmap. URL: http://europa.eu.int/comm/food/food/biosafety/bse/roadmap_en.pdf, 2005) as the main condition for lifting the extended feed ban. Methods based on polymerase chain reaction (PCR) seem to be a promising solution for this aim. The main objective of this study was to determine the applicability of four different real-time PCR methods, developed by three National expert laboratories from the European Union (EU), for the detection and identification of cattle or ruminant species in typical compound feeds, fortified with meat and bone meals (MBM) from different animal species at different concentration levels. The MBM samples utilized in this study have been treated using the sterilization condition mandatory within the European Union (steam pressure sterilization at 133 degrees C, 3 bar, and 20 min), which is an additional challenge to the PCR methods evaluated in this study. The results indicate that the three labs applying their PCR methods were able to detect 0.1% of cattle MBM, either alone or in mixtures with different materials such as fishmeal, which demonstrates the improvement made by this technique, especially when compared with results from former interlaboratory studies.  相似文献