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41.
42.
Raphaël Trouvé Thomas Drapela Thomas Frank Franz Hadacek Johann G. Zaller 《Biology and Fertility of Soils》2014,50(1):13-23
Invasion of non-native species is among the top threats for the biodiversity and functioning of native and agricultural ecosystems worldwide. We investigated whether the herbivory of the slug Arion vulgaris (formerly Arion lusitanicus; Gastropoda), that is listed among the 100 worst alien species in Europe, is affected by soil organisms commonly present in terrestrial ecosystems (i.e. earthworms—Annelida: Lumbricidae and arbuscular mycorrhizal fungi—AMF, Glomerales). We hypothesized that slug herbivory would be affected by soil organisms via altered plant nutrient availability and plant quality. In a greenhouse experiment, we created a simple plant community consisting of a grass, a forb, and a legume species and inoculated these systems with either two earthworm species and/or four AMF taxa. Slugs were introduced after plants were established. Earthworms significantly reduced total slug herbivory in AMF-inoculated plant communities (P?=?0.013). Across plant species, earthworms increased leaf total N and secondary metabolites, AMF decreased leaf thickness. Mycorrhizae induced a shift in slug feeding preference from non-legumes to legumes; the grass was generally avoided by slugs. AMF effects on legume herbivory can partly be explained by the AMF-induced increase in total N and decrease in C/N ratio; earthworm effects are less clear as no worm-induced alterations of legume plant chemistry were observed. The presence of earthworms increased average AMF colonization of plant roots by 140 % (P?<?0.001). Total shoot mass was significantly increased by AMF (P?<?0.001). These data suggest that the feeding behavior of this invasive slug is altered by a belowground control of plant chemical quality and community structure. 相似文献
43.
S Franz M Hofmann-Parisot M Gumpenberger 《Berliner und Münchener tier?rztliche Wochenschrift》2001,114(5-6):202-209
Beside the clinical examination of udder/teat imaging methods e.g. sonography, radiography and endoscopy allow diagnosis. This publication will give a summary of currently used and potentially usable methods of diagnostic imaging applied to the teat. Advantages and disadvantages of the several methods were compared--as quoted in literature and completed by own experiences. 相似文献
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F. Lahnsteiner 《Fish physiology and biochemistry》2002,27(1-2):49-59
The present study investigated the influence of ovarian fluid (OV) on the gamete physiology in the brown trout (Salmo trutta f. fario). In comparison to water OV prolongs the duration of sperm motility for >'5 min and the fertilizability of eggs for >'10 min independent from the quality of the egg batch from which the OV derived. These stabilizing effects are related to the inorganic composition of OV as similar results are obtained in buffered artificial saline solution (AFS). OV compensates also for sub-optimal environmental conditions as demonstrated in fertilization experiments with mixtures of OV and buffer solutions of different pH. At a dilution ratio of OV: water of 1:1 the stabilizing effect on gametes is significantly decreased and at a dilution ratio of 1:8 it is completely lost. Due to the described effects significantly higher fertilization rates are obtained in OV than in water. In OV the fertilization rates are also higher than in AFS but only at low sperm to egg ratios or when semen with low motility rates and swimming velocities is used. This is considered to be due to a semen dependent egg activation which is partly suppressed by a OV protein with a molecular weight between 20 and 62 kdaltons. The phenomen is discussed in detail. 相似文献
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Franz Bichlmaier 《European Journal of Forest Research》1970,89(1):356-362
Summary One of the essential aims of land planning is to satisfy the people's need for recreation. For this purpose it seems to be
efficient to differentiate between “local” recreation and “long-distance” recreation areas and to consider them separatly
in regional planning. To determine the location of recreational forests we need appropriate aids for decision making. Therefore
activities that bring about deterioration of natural conditions, e.g. water pollution, soil erosion etc., as well as injuries
to the optical value of the landscape, are not allowed in natural recreational areas. On the other hand it is possible to
delimit forests after an analysis of stand composition and also by interpretation of maps giving the physiological effects
of the climate.
Above all the habits of the people are of importance, especially when they are based on irrational motives. These factores
are of great importance in addition to the sociological conditions of an area and therefore do not allow the organization
of long-distance recreation areas from simply a regional point of view. In the case of areas designed for local recreation,
however, it might be sufficient to appraise the demands of the people through a regional analysis.
Herrn Professor Dr. Dr. h. c.Julius Speer zum 65. Geburtstag gewidmet. 相似文献
Herrn Professor Dr. Dr. h. c.Julius Speer zum 65. Geburtstag gewidmet. 相似文献
50.
F. Lahnsteiner 《Fish physiology and biochemistry》2000,23(2):107-118
In rainbow trout (Oncorhynchus mykiss) freshly ovulated eggs and over-ripened eggs which had been retained in the coelomic cavity for 7, 14 and 21 days were investigated in aspects of morphology, physiology and biochemistry. Egg viability was significantly reduced from 85.9±16.4% in freshly ovulated eggs to 25.1±21.9% in over-ripened eggs which had been retained in the coelomic cavity for 21 days. Further during over-ripening in the ovarian fluid the pH significantly decreased, while the levels of proteins, of esterified and non esterified fatty acids and the activities of aspartate aminotransferase and acid phosphatase significantly increased. Also egg parameters changed: the wet weight of the unhardened eggs increased, the weight increase during hardening and the levels of esterified and of non esterified fatty acids significantly decreased. In freshly ovulated eggs the yolk consisted of a homogenous mass and the perivitelline space was small, but in over-ripened eggs the yolk was non homogenous with numerous vesicular inclusions and the perivitelline space was enlarged. When freshly ovulated eggs were incubated in water the cortical reaction was detectable within 5 min, in over-ripened eggs hardly no extrusion of cortical vesicles was visible and the width of the perivitelline space was very irregular.For the investigated freshly ovulated and over-ripened samples the egg viability significantly correlated with ovarian fluid parameters (pH, protein, non esterified fatty acids, esterified fatty acids, aspartate aminotransferase, acid phosphatase) and egg parameters (weight increase during hardening, weight of the hardened eggs). 相似文献