Acta Facultatis Ecologiae - Technická univerzita vo Zvolene

155Fig. 5 Compression of wood formation during the1995–2007 period in the living branchesof the Pinus sylvestris from the dump-fieldFig. 8 shows comparison of width of yearshoots from the analyzed samples of Betula pendulafrom the dump-field and reference site. Thewidth of year shoots is narrower in sample from thedump-field. It suggests more stressful conditionsfor vegetation at the dump-field. The zonal occurrenceof thick-walled and thin-walled libro-shapedfibres, scalar perforation and hyphae in vessels ispossible to observe in the cross-section of livingbranches of Betula pendula from the dump-fieldby detail enlargement (Fig. 9). In living branchesof Betula pendula membranes of axial parenchymaand parenchyma of medullary ray are enzymaticdecomposable and parenchyma of medullary ray iswithout stock substances. Irregular width of yearshoots and preferential setting of vessels into radialFig. 6 Comparison of the current year shoots in analysed samples of the Betula pendula.Sample LB–7 from the: 1 – living branches. 2 – dead branches; sample LB–10 from reference site:3 – living branches. 4 – dead branches.groups is possible to be observed in the cross-sectionof live branches from the reference site. Membranesof thinned parenchyma of medullary raywere enzymatic decomposabled.Changes of pH and oxidative-reductive potentialaffect the release and precipitation of heavymetals. It causes the heavy metals transfer into thebottom sediments, solution or soil/rock environment.Bowen [13] states that Ag, As, Cd, Cu, Pb,Sb and Zn metals have the tendency to accumulatein the upper soil horizon due to vegetation recycling,atmospheric deposition and adsorption byorganic mass. Fe, Co and Ni metals usually accumulatein higher concentrations in dislocated clayminerals and autigene sesqui-oxides in lower horizonof the soil profile enriched in clay and oxyhydroxidecomponents.Fig. 7 Living branches of Betula pendulafrom dump-field; zonal occurrenceof thick-walled fibres.