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Effect of soil acidification on the growth of Korean pine (Pinus koraiensis) seedlings in a granite-derived forest soil.

The growth of pine trees has diminished in recent years in industrial areas of Korea. Soil acidification is believed to be responsible. To study its effects, we grew seedlings of three-year-old Korean pine in brown forest soil derived from granite, which had been treated with an acid solution, for 182 days. The anion mol ratio in the solution was SO4(2-):NO3-:Cl-=5:3:2, which is the average in the total precipitation in Korea; six H+ ion concentrations in the soil were studied (0 (control), 10, 30, 60 and 90 mmol H+.kg-1). With increasing amounts of H+ added to the soil, the concentrations of Ca, Mg, K, Al and Mn increased, especially below a soil pH of 3.8. The concentrations of Ca, Mg and K in pine needles and stems increased with increasing H+ added to the soil, whereas their concentrations in the root decreased. Conversely, the concentration of N and P in each organ of the pine plant was higher in all treatments than in controls. Also, the concentrations of Al and Mn increased significantly in all organs of the plant with increasing H+. We also estimated the effect of deliberate soil acidification on tree growth, using the molar ratio (Ca+Mg+K)/Al as an indicator of soil acidification. A strong positive correlation was found between the total dry mass (TDM) of seedlings and the (Ca+Mg+K)/Al molar ratio calculated from the concentrations of water-soluble elements in soil (r=0.99, p<0.001). When the (Ca+Mg+K)/Al molar ratio reached 1.0, the relative TDM had fallen to 40%. These results show that deliberate soil acidification reduces the growth of the Korean pine less than it does the Red pine, which has been the dominant species in Korea.

Acids↗

[Effects of soil temperature and humidity on soil respiration rate under Pinus sylvestriformis forest].

Employing root-wrenching method and LI-6400-09 soil respiration chamber, this paper measured the diurnal changes of soil respiration rate with and without roots in situ on June 17, August 5, and October 10, 2003. The seasonal changes of soil respiration were also measured from May to September, 2004. The results showed that both the total and the root-wrenched soil respiration appeared single diurnal pattern, with the peaks presented during 12:00-14:00. The diurnal fluctuation of soil respiration on August 5 was smaller than that on June 17 and October 10. There were also obvious seasonal changes in total and root-wrenched soil respiration, as well as in root respiration, which were higher from June to August but lower in May and September. The average total soil respiration, root-wrenched soil respiration, and root respiration were 3.12, 1.94 and 1.18 micromol CO2 x m(-2) s(-1), respectively, and the contribution of roots to total soil respiration ranged from 26.5% to 52.6% from May to September, 2004. There were exponential correlations between respiration rate and soil temperature, and linear correlations between respiration rate and soil humidity. The Q10 values were 2.44, 2.55 and 2.27 for total soil respiration, root-wrenched soil respiration, and root respiration, respectively. The effect of soil temperature on root-wrenched soil respiration was lager than that on total soil respiration and root respiration. Soil humidity had a larger effect on total soil respiration than on root respiration and root-wrenched soil respiration.

China↗

[Effect of accumulating fluorine and sulphur compounds on the content of chlorophyll in pine needles (Pinus sylvestris L.) from some areas of southern Poland in 2001-2003].

Concentrations of F(-), S and chlorophyll in needles of pines growing near metallurgical works and power plants were determined. A statistically significant positive correlation between F(-) (in the range of 4.32 to 21.98 microg F(-)/g d.m.) and chlorophyll and a negative correlation between S (in the range of 1094 to 2150 microg S/g d.m.) and chlorophyll was found. This result suggests an antagonistic interaction between F(-) and S in pine needles.

Chlorophyll↗

Production of cytokinin-like substances by mycorrhizal fungi of pine (Pinus sylvestris L.) in cultures with and without metabolites of actinomycetes.

Studies on the effect of post culture liquids of actinomycetes on cytokinin-like substances production by mycorrhizal fungi have revealed that actinomycete metabolites inhibited or stimulated the synthesis of these compounds. The results of chromatographic analyses suggest, that substances stimulating the soybean callus are likely to be: riboside 6 (gamma, gamma-dimethylallylamino) purine and riboside zeatin. Using gas chromatography it was confirmed that both substances are produced by Rhizopogon luteolus. Paxillus involutus synthesizes probably besides the two substances also zeatin, as appears from the data obtained by column chromatography.

Actinomyces↗

Production of organic acids by bacteria isolated from soil, rhizosphere and mycorrhizosphere of pine (Pinus sylvestris L.).

The bacteria studied released into the medium ten to eleven organic acids. Soil organisms excreted mainly pyruvic and alpha-ketoglutaric acids, while strains from the root zone--gluconic acid and unidentified uronic acid (y2). Mean indices of total production of the organic acids by bacteria were in the following order: rhizosphere less than soil less than mycorrizosphere. Bacteria from the root zone released into the medium very large amounts of pyruvic, gluconic, and uronic (y2) acids--in some instances several times higher than bacterial dry mass.

Arthrobacter↗

Free amino acids production by ectomycorrhizal fungi of pine (Pinus sylvestris L.).

Studies on free amino acids production by five species of ectomycorrhizal fungi (Amanita muscaria, Suillus granulatus, Suillus luteus, Suillus bovinus and Rhizopogon luteolus) show that all the fungi produced mainly: glutamic acid, leucine, lysine, ornithine, arginine and an unidentified ninhydrin-positive compound X3. Both the quality and quantity of amino acids released was different in the fungal species studied. The predominant amino acids in post-culture liquids in general did not exceed 1.5 micrograms/mg dry mass.

Agaricales↗

Production of B-group vitamins by bacteria isolated from soil, rhizosphere, and mycorrhizosphere of pine (Pinus sylvestris L.).

Studies on the production of B vitamins by soil, rhizosphere, and mycorrhizosphere bacteria have revealed that such ability is common among these organisms. Thiamin, nicotinic and folic acids were produced by the greatest number of bacteria. Bacteria isolated from the rhizosphere and mycorrhizosphere produced more riboflavin than those originating from the soil distant from roots. In general the soil strains produced higher amounts of vitamins (except riboflavin) than the root-zone isolates. Two and three vitamins were produced by the majority of bacteria. The synthesis of four and five vitamins was found in few strains only.

Bacteria↗