SUMMARYThe present study was performed on mature Norway spruce trees {Picea abies L.) with needle losses in the range of 25-35 %. The trees were growing at three altitudes (870, 1270, and 1700 m above sea level) in a mountain forest in the Calcareous Alps of Bavaria. The objectives were to assess the role of climate and pollution in addition to nutrient disorders for damage to spruce trees. During the growing season the average temperature was up to 5 °C lower and the average ozone concentration was about twofold higher at the high altitude in comparison to the low altitude (13 and 18 °C, and 60 and 35 nl T^ ozone, respectively); the average NO^ and SO^ concentrations did not exceed 5 nl 1"^ Foliar analysis of pollutants did not indicate critical levels of Pb, Cd, Cl, F and S. Biometrical parameters, foliar element composition, pigment and protein content of the needles were determined during four seasons. Average dry:fresh weight ratios, specific needle weights, projected needle areas, soluble protein and carotenoid contents were similar within the 20 % range for needles from all three altitudes. Foliar analysis of nutrients indicated a low nutrient status especially for nitrogen, and showed a phosphorus deficiency in needles from the three sites. The chlorophyll content of the needles decreased with increasing altitude. Since nutrient imbalances were greatest in needles from the lowest site, it was concluded that the greater damage to spruce trees and lower chlorophyll content of the needles at altitudes > 1000 m above sea level were not caused by nutrient disorders.

During and after prolonged periods of rainfall in late spring, blighted young twigs of European beech (Fagus sylvatica) were frequently observed in several beech stands in south-western and southern Germany. Long and short shoots of young understorey trees or lower branches up to 1.5 m above the soil level were affected. Symptoms also occurred regularly on twigs in heights up to 2 m and more above the ground. Necroses usually expanded within the current yearÕs tissue and often also reached into the previous yearÕs wood. Ponding rain water in the stands or along forest roads or open soil seemed to promote the disease. Of a total of 54 symptomatic twigs collected in four stands, 37 revealed Phytophthora isolates, of which 33 were P. plurivora and four were P. cambivora. Both species caused extensive lesions on beech twigs in laboratory pathogenicity tests. Patterns of the disease indicated that these pathogens, generally considered soilborne species, in most cases are transmitted from the soil to above-ground parts of the trees via rain splash. In larger heights, however, other vectors such as snails might be responsible for transmission. Although Phytophthora spp. are well known as causal agents of seedling blight as well as root and cambium rot and aerial bleeding cankers of mature beech, to our knowledge this is the first report of a twig blight in beech associated with soilborne Phytophthora spp. In particular in periods of high precipitation, this disease might pose an additional threat to Central European beech forests, especially endangering the success of artificial and natural regeneration of beech in affected stands.

The aim of this study was to evaluate the computed tomography (CT)-imaging potential of iopromide-carrying liposomes (SPC/CH/SPG, 6:3:1) of approximately 200 nm in diameter in healthy rabbits and in rabbits with implanted liver tumors in an intraindividual comparison with iopromide. Normal rabbits and animals with VX2 tumors implanted into the liver received iopromide (600 mg of iodine/kg, bolus injection) and, 1 or 2 days later, iopromide liposomes (300 mg of iodine/kg, bolus injection or 10-minute infusion). CT imaging up to 1 hour after administration was performed, focusing on the aorta, vena cava, kidney, spleen, and liver. Pharmacokinetic parameters for CT enhancement were calculated. Detectability and delineation of liver lesions were assessed on a 4-grade scale, and differences were evaluated statistically. Using half the iodine dose, iopromide liposomes achieved similar blood-pool enhancement as iopromide. Detectability and delineation of liver lesions were easy/good in the arterial phase after iopromide injection, but poor in the venous and equilibration phases. Iopromide liposomes resulted in a long-lasting, good detectability and delineation of liver lesions similar or superior to that observed after iopromide in the arterial phase.

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