Gregor Kraus

Gregor Konrad Michael Kraus, Conrad Gregor Michael Kraus ( born May 9, 1841 in Bad Orb, † November 14, 1915 in Würzburg ) was a German botanist and university professor. Kraus is considered one of the founders of micro- climatology and experimental ecology. Its official botanical author abbreviation is " Kraus ".

Life

The son of a teacher attended high school in Aschaffenburg and studied medicine from 1860 at the University of Würzburg, where he in 1866 with a thesis "On the construction of dry Pericarpien " Dr. phil. received his doctorate. After that, he was a research assistant at Julius Sachs at the University of Bonn and joined thereto at the University of Freiburg. 1867 Habilitation at the University of Würzburg with the theme " tissue tension of the tribe and its consequences " and appointment as Assistant Professor in Würzburg. From 1868 he was a research assistant at the Botanical Institute of the University of Leipzig. In 1869 he was appointed as a full professor and director of the botanical garden at the University of Erlangen, where he worked until 1972. In 1872, he was the successor of Anton de Bary Professor and Director of the Botanical Garden at the University of Halle. In 1898, he was the successor of Julius Sachs at the University of Würzburg.

Research

His scientific interest was initially the anatomy of plants, especially the fossil and trees. Because of his special knowledge in this field Krause was used among other things in the determination of data collected by the 2nd German, directed by Carl Koldewey North Polar Expedition driftwood. In Erlangen and Halle, he dealt with the physiology of plants, where he gradually developed ecological issues and as one of the pioneers of the ecophysiology was. First, he explored the properties of chlorophyll which he used new methodological approaches, such as spectral analysis. With its metabolic studies of crassulacea he stripped aspects of the water balance of plants, in his work on the physiology of the tannins he devoted himself among others, the ecological importance of this class of substances. Kraus took multiple research trips, so 1893/1894 to Java and 1896/1897 to India.

As director of the Botanical Garden of the University of Halle, he introduced a new concept, in which he arranged the plants according to their relationship as well as physiognomic aspects. This type of presentation, he later led a well in Wurzburg, it is meanwhile in many botanical gardens the rule. Ecological aspects came with him to advantage, as, by laying out a large complex of alpine plants, a collection of German salt plants. For an extension of the stock of cold house plants provided a foundation of the industrialist Carl Adolph Riebeck widow.

Kraus is considered one of the founders of micro- climatology. His research in this area, he summed up in his 1911 book " The climate and soil in a small space: an attempt to exact treatment of the site on the Wellenkalk ", which is now regarded as one of the first plant ecological works in which the conditions of existence of the plants with chemical and physical methods are described and analyzed. He also created the basis for the experimentally -ecological analysis of the distribution of plants. In addition, Kraus was with his studies as a model for careful site analysis and has given a significant impetus for the development of the then young science of ecology.

The known fact that often very considerable differences in terms of temperature, air movement and relative humidity can be observed within a seemingly uniform climate area in a small space, and this becomes apparent in a change of the vegetation was already known before Kraus. His merit is that he conceptualized these relationships for the first time on a section of the landscape, namely the shell limestone mountains of the middle Main valley with exact methods of investigation over a long period of time.

During his investigations he carried out numerous chemical soil analysis, examined the soil profile and the grain size of the soil, ie the proportion of the skeleton and fine earth, the water content and the temperature of the soil, temperature and wind at different heights above the ground.

Here, for example, showed that the " Kalkvegetation " is dependent on a particular carbonate content in the soil less, but that their training is primarily determined by the physical soil conditions. Calcareous soils generally have a high proportion of the skeleton. Such soils are the drier and heat up the faster and higher, which has a significant impact on the plant community.

Next he has found in his exact temperature measurements show that in the lowest layers of the atmosphere immediately above the ground daily temperatures often exceed 10 ° C higher than the air measurements suggest that detect the air temperature by default in 2-3 m height above the ground.

His measurements and experiments led Kraus to the hot and dry limestone slopes at Gambach - by where he bought a then non-managed two permanent plots. This land later passed into the possession of the Natural Science Association of Würzburg and became the core of today under reserve.

Works

• The botanical garden of the University of Halle. From 1888 to 1893.
• History of plant introductions to the European botanical gardens. In 1894.