Climatic Conditions Of Central Europe Research Articles

Endophytic fungi and alkaloid production in perennial ryegrass in Germany

AbstractInfection with Neotyphodium endophyte was detected in 33 of 38 ecotype populations of Lolium perenne originating from old grassland at four widespread sites in Germany. The frequency of individual infected plants of the different populations ranged mostly from 1% to 30%; a few populations showed higher infection levels, up to 80%. The contribution of endophyte‐positive plants to the biomass of the original swards was estimated to range from 1% to 34%.Concentrations of the indole alkaloid lolitrem B detected in the endophyte‐positive German ecotypes were similar to those in the endophyte‐positive cultivars‘Ellett’and‘Grasslands Nui', originating in New Zealand, when all were cultivated under the climatic conditions of northern Germany. A seasonal variation in lolitrem B concentrations was observed from 1993 to 1996. The highest concentrations, 0·8–1·4 mg kg−1 dry matter of herbage, were recorded during the months of July and August. These concentrations were not considered to be sufficient to induce‘ryegrass staggers', a neurological disorder in grazing animals. It is concluded that further research is necessary to elucidate the implications of grass endophytes under the climatic conditions of Central Europe.

The self-sufficient solar house in Freiburg—Results of 3 years of operation

Energy efficiency is the key to buildings with minimized environmental impact. The combination of this approach with active and passive solar energy utilization can lead to purchased energy demand close to zero. Nevertheless, energy autonomy under Central European climatic conditions requires seasonal energy storage, especially energy with a high exergy content. The Fraunhofer Institute for Solar Energy Systems built an energy autonomous house in Freiburg, Germany, in 1992. Highly efficient solar systems are combined with a hydrogen-based seasonal-storage system. Long-term storage of low-temperature heat was avoided by extensive passive solar energy utilization. After describing the project, this paper focuses on the experience of nearly 3 years of operation.

Climate of the Tatra Mountains

The typical alpine landscape of the Tatra Mountains has the greatest range of climatic conditions in Central Europe and, as a result, distinct altitudinal climatic zones and corresponding vegetation belts. The climate is determined by solar radiation and the major air circulation belts, modified by orographic factors -elevation, exposition, and inclination. All the main climatic elements (air temperature, precipitation, and snow cover) and different bioclimatic conditions are described in this paper. Diagrams indicate the frequency of the major climatic components and the human response to various weather factors. Results of recent research suggest that climatic changes resulted from the increasing influence of air mass advection from the Atlantic Ocean during the last twenty years. In the alpine belt, a significant decrease in mean annual temperatures was observed between 1968 and 1982 which relates to shorter periods of sunshine. Relatively wet conditions occurred from 1960 to 1980.

Seasonal Trends in Energy Contents of Storage Substances in Evergreen Gymnosperms Growing Under Mild Climatic Conditions in Central Europe

From the contents of the soluble sugars, starch, and total lipids measured at monthly intervals during the course of a year in leaves and barks of Taxus baccata, Juniperus communis, Thuja occidelltalis, Picea excelsa and Sequoiadendrom giganteum the energy contents of storage substances were calculated and their seasonal trends established. From Taxus and Juniperus the wood was investigated in the same manner. Furtheron, the seasonal trends in total N-contents of leaves and barks of Taxus , Juniperus and Thuja were measured. As energy storing substances the N-compounds are not important. From the seasonal trends of the N-contents a function of the old leaves as an important N-storage pool for the budding may by concluded. In the one year old needles of Picea and Taxus the carbonic acid contents were measured, from an energetic point of view the acids are not important as reserve-substances. From the seasonal trends of the energy contents in the different species a general pattern of storage in gymnosperms growing under mild climatic conditions in Central Europe was deduced (Fig. 9). Remarkably, according to this pattern the highest amounts of starch are found in the spring or early summer, the maximum contents of total lipids are reached during autumn or early winter and the highest contents of soluble sugars are found in the winter. This pattern confirms earlier assumptions regarding the functions of different storage substances. The total energy contents decline during the growth period and reach their lowest values in the late spring and early summer. In the winter none of the species showed an extensive diminution of storage energy, but rather sometimes a rise was seen which points to a net production during the winter months. Thus, the highest energy contents in the leaves are often found in the winter. The old needles have an important function as storage sites in the evergreen gymnosperms.