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Bean plants (Phaseolus vulgaris L.) were subjected to simulated acid mist treatments (pH 4.5, 3.0, 2.3) in the greenhouse. Solutions containing either HNO3 or H2SO4 were applied as mists over a period of 31 days. The growth medium had a pHKCl of 7.9 and a calcium (Ca) content of 18.5 mg g-1. Plants were sampled at flowering and at ripening, for determination of length, fresh and dry weights of different plant organs, and number of nodules. The plant samples were analyzed for nitrogen (N), sulfur (S), and phosphorus (P) content. A significant reduction of stem growth was recorded as a result of the treatment. Some of the plants had interveinal chlorosis, indicating mild iron (Fe) or manganese (Mn) deficiency caused by the high soil pH. The lowest leaflet dry weight was 86% of the control at a dry matter content of 90% of the control. A reduction in shoot:root dry mass ratio was detected. Pod dry weight was not affected. High increases in leaflet N (145%) or S (204%) content were found, which were roughly proportional to the respective treatment levels of HNO3 or H2SO4. Phosphorus content and N:P ratio of leaflets responded to treatment levels and chemical composition of treatment solutions. The root S content was affected only slightly. Nodules were more sensitive to HNO3 treatment, which at pH 2.3 reduced the number of large nodules to 14% of the control at flowering. At ripening of the pods, the effect of treatments on nodules was less pronounced. H2SO4 treatment also reduced the nodule numbers at higher acidities of mist. Nodule numbers at different treatment levels covaried in all variants with stem height growth, shoot:root dry mass ratio and P content in pods. In HNO3 treated plants, the numbers of root nodules changed inversely to the S content in leaflets. It was concluded that an increase in S content in the plants was less than an increase in N content. The hypothesis that H2SO4 mist causes more disturbances in bean plants than HNO3 mist was not... [ABSTRACT FROM AUTHOR]

The influence of alkaline dust pollution (pH of water solution of dust 12.3--12.7) from a cement plant (Kunda town, Estonia) on chlorophylls and carotenoids of the needles of 60--80 year old Norway spruce was studied on sample plots established at different distances from the emission source. The highest sensitivity to dust impact was measured in the content of Chl a, Chl b, carotenoids and elements regulatingor participating in the biosynthesis of pigments (Mg, Fe, N, Mn). [ABSTRACT FROM AUTHOR]

The concentration of heavy metals in soil and in Scots pine (Pinus sylvestris) organs growing on a pH gradient from 4.0 to 7.9 of soil at different distances from a cement plant was monitored. Emission for over 40 years of alkaline dust (pH 12.3-12.6) into the atmosphere in North Estonia had resulted in alkalisation and elevated concentration of total heavy metals in upper layers of the soil (0-30 cm), which was considerable even 10 years after the dust pollution stopped. Monitoring showed that the accumulation and allocation of heavy metals varied between the stem, shoots and needles and differed from the trees in the unpolluted area, depending more on the mobility of elements and the pH than element concentrations in the alkaline soil. A strong negative correlation was found between the soil pH and Mn, Zn and Cd concentrations in different tree organs. Compared to the unpolluted area, Pb was present in relatively higher concentrations in all organs but Cr, Fe and Cu in needles and shoots. The concentrations of Mn and Cd were much lower than control in all organs of trees in alkalised soil. The height increment and density of needles on shoots were predominantly in negative correlation with the pH of soil.

The investigation was carried out in 8-year-old Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) plantations on post-mining area, Northeast Estonia. The aim of the study was to assess the suitability of lodgepole pine for restoration of degraded lands by comparing the growth, biomass, and nutrient concentration of studied species. The height growth of trees was greater in the Scots pine stand, but the tree aboveground biomass was slightly larger in the lodgepole pine stand. The aboveground biomass allocation to the compartments did not differ significantly between species. The vertical distribution of compartments showed that 43.2% of the Scots pine needles were located in the middle layer of the crown, while 58.5% of the lodgepole pine needles were in the lowest layer of the crown. The largest share of the shoots and stem of both species was allocated to the lowest layer of the crown. For both species, the highest NPK concentrations were found in the needles and the lowest in the stems. On the basis of the present study results, it can be concluded that the early growth of Scots pine and lodgepole pine on oil shale post-mining landscapes is similar.

Waste management of clinker dust by spreading it on forest soil was studied in a 25-year-old Scots pine stand on acidic sandy soil. Clinker dust (0.5 kg m⁻²), fertiliser (N, P, K, Mg, 0.05 kg m⁻²; N 190 kg ha⁻¹) and untreated soil were applied on 120-m² plots in four replicates. The fertiliser was included to confirm the nutrient limitation in the stand. Clinker dust increased the soil pH by 1.2 units relative to the pH of 4.6 in the untreated soil by the second year. Soil K and Mg concentrations were larger in the dust and fertiliser treatments. Nutrient diagnostics indicated that needles of untreated trees were deficient in N and K. Fertiliser treatment indicated that the growth of trees was limited by N, since the fertiliser tended to increase needle K, N, N/P, needle dry mass and diameters of stem and shoots. By an auxiliary dataset, no effects of the dust and fertiliser on possible excess of the micronutrient Mn were observed. Clinker dust increased needle K concentration, but due to the N limitation, there was no increase in the growth of stems, branches, shoots and needles. It was concluded that in plots of 120 m² application of clinker dust at a rate of 0.5 kg m⁻² was safe for the 21-year-old Scots pine stand in this trial on an acid nutrient-poor sandy soil during 4 years after the treatment.

The growth of Scots pine and its suitability for afforestation of post-mining landscapes in Northeast Estonia were assessed in comparative analytical studies by using morphological parameters and mineral nutrition characteristics. The growth and nutrient uptake of Scots pine growing on post-mining substrate were compared with the characteristics of pines of the same age (22-23 years) in a Calluna forest site type predominant in North Estonia in similar climatic zone. Results of the analyses of soil upper layers showed that the concentration of N and P in soil did not differ between the opencast spoil and Calluna site, but significantly higher pH of soil and concentrations of K, Ca, and Mg were found in mine spoil. The concentrations of K and Mg in needles were significantly higher in the post-mining area, but the concentrations of N, P, and Ca did not differ significantly. Comparison of the needle nutrient concentration with the standard for optimum concentrations revealed P deficit in the post-mining area and P and K deficit in the Calluna site. Scots pine formed longer and thinner needles and shoots in the post-mining substrate than in the Calluna site. It was assumed that in the post-mining area the growth of pines is predominantly dependent on K and Ca concentrations in their tissues as the biomass of needles was strongly correlated with the K/Ca ratio, whereas the biomass in the Calluna site was correlated with the N/P ratio. The height and diameter of trees were significantly larger in the post-mining area.

Alkalisation of soil has been assumed to be the principal cause of changes in vertical gradients of nutrients in Pinus sylvestris crown. The long-term influence of alkaline dust pollution (pHH2O 12.3-12.6) emitted from a cement plant on the element composition of soil and needles of Scots pine in different canopy layers was studied. In the polluted area, the pH of soils was >7, and high amounts of Ca, K and Mg were measured in the upper layers of soil (0-30 cm), while the mobility and solubility of some contaminants have decreased, nutrition processes have become complicated, and imbalance of mineral composition of trees was revealed. Reduced N and increased K, Ca and Mg concentrations in needles were observed in the heavily polluted area. Vertical gradients of elements and their ratios in canopies varied depending on the alkalisation level of soil. Needles on the upper-crown shoots had higher concentrations of N, C, Ca and Mg and lower concentrations of P and K compared to the lower layer of the crown. In the unpolluted area, higher concentrations of N, P, K and Ca were found in lower-crown needles and of C and Mg in needles at the top of the canopy. The P/N ratio below 0.125 indicated P deficiency in pines. The ratios N/Ca, N/Mg and N/K had significantly decreased, while the ratios Ca/Mg, K/Mg and K/Ca had a tendency to increase in heavily polluted sample plots. Magnitude of changes of element ratios indicates on the disbalances of availability and translocation of nutrients in the crown of trees.

Long-term influence of alkaline dust (pH 12.3-12.7) pollution emitted over 40 years from a cement plant in Estonia was the reason of alkalisation (pH 6.7-7.9) and high concentrations of K, Ca and Mg in the soil of affected territories. Although dust emission has diminished during the last 10 years, the imbalances in nutrition substrate and their influence on the growth of trees are notable up to now. The study of morphological and physical properties of 70-80-year-old Scots pine (Pinus sylvestris L.) crown, stems and stemwood from three different air pollution zones showed serious deviations in comparison with a relatively healthy forest in an unpolluted area. The specimens from polluted trees, if compared to reference site, showed significantly smaller height growth, radial increment and width of annual rings of sapwood. In heartwood wider annual rings were found in polluted areas. In the period of heartwood formation the dust pollution level emitted from the plant was relatively modest and cement dust, which contains elements necessary for mineral nutrition of trees, may have acted as fertiliser. The moisture content in sapwood and heartwood, especially in the upper layers of stems, was lower in the polluted area than in reference site trees. Regression analysis revealed a strong dependence between latewood percentage and sapwood or heartwood in stems of Scots pine in all sample plots.

The study was aimed at the quantitative evaluation of the temporal and spatial partitioning of non-structural carbohydrates and needle biomass in a canopy of Scots pine (Pinus sylvestris L.) growing in a Myrtillus site type forest stand (predominant in Estonia). The tree canopy was divided into ten equal layers and the material for the spatial partitioning of the investigated characteristics was sampled from all layers. Our findings revealed a significant variation in morphology and in the partitioning of carbohydrates in needles in different layers of the canopy. The study of the temporal dynamics of carbohydrates showed that starch content in needles started to increase in early spring before budbreak, which was accompanied by a decline in soluble carbohydrates. In October, the starch content of needles was low, but the concentration of soluble sugars started to increase attaining a maximum in winter. Regression analysis indicated that before budbreak, the partitioning of soluble sugars in different canopy layers was relatively weakly correlated with the height of the layer; however, a strong correlation was observed for starch. In autumn, when the growth of trees stopped and daily temperatures decreased, the allocation of soluble sugars was correlated with the height of the canopy layer.