The Quality of Stemwood of Pinus sylvestris in an Alkalised Environment
2007
Mandre, Malle | Korsjukov, Reet
The impact of long-term dust pollution emitted from a cement plant on soil chemistry, and the concentrations of plant nutrients, lignin, cellulose and hemicellulose in the stemwood of 80–85-year-old Pinus sylvestris was investigated at different distances from the emission source. It was found that alkaline cement dust (pH 12.3–12.6) emissions for over 40 years resulted in an alkalisation (pH 6.7–7.9) of the polluted soil compared to a pH value of 3.8 in unpolluted soil. There were also nutrient imbalances in the soil, as well as certain disturbances in mineral nutrition processes and accumulation of nutrients in the tree stems. The average concentrations of K, Ca and Mg in stems were higher and those of N and P lower than in the unpolluted area. The lignin (L) content in stemwood increased, hemicellulose (Hc) decreased, while cellulose (Ce) did not change. A variation in the partitioning of L, Ce, Hc and nutrients between different sections of stems and between trees from different sample plots was found. L, Ce and Hc were not related to the internal K, Ca and Mg concentrations. Correlations were established between L, Ce, or Hc content and C content, and between L and Hc content in stem tissues. The contents of wood components were not related to N or P in the alkalised areas, but seemed to be more associated with P than with N. Alterations in the arbitrarily chosen ratio L/(Ce + Hc) indicated changes in wood quality, and a negative correlation with N/P was found in stem tissue in the polluted area, while positive correlations with N/Mg and Ca/Mg were found in the control area.
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