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The paper concerns changes of chemical composition of water in headwater streams in the valley of the Kamienna, left bank tributary of the Słupia River (54°19′N; 17°10′E). Water samples were collected in 2012 from three streams, in their upper, middle and lower course every month. Analysis included water temperature, pH, conductivity, and the content of dissolved oxygen, HCO3– , K+, Na+, Ca2+, Mg2+, NH4+, Cl–, NO3–, PO43– and SO42–. Water of the analysed streams was characterized by generally low concentration of solutes (tab. 1) and had bicarbonate−calcium character. The observed low variability of water temperature along the streams resulted from their shortness and rapid flow. Low variability was also observed in case of pH and Mg2+ content. Increasing trends downward the streams were noticed for dissolved oxygen, while decreasing changes were observed for HCO3–, NO3– and PO43–. The remaining components showed different trends in the individual streams, indicating importance of local−scale factors.
The paper presents the result of the studies on the properties of soil organic matter in Sapric Histosols associated with mid−forest spring niches in the valley of the Kamienna Creek, left bank tributary of the Słupia River (northern Poland). We sampled five soil profiles at the depth of every 10 cm until the mineral bed was reached. We analyzed degree of peat mass decomposition, reaction and the content of organic matter, total organic carbon and total nitrogen. Fractional composition of soil organic matter was analyzed with Schnitzer method. We measured the absorbance at wavelenghts of 280, 465 and 665 nm in 0.01% alkaline solutions of humic acids and the absorbance ratios A2/6, A2/4 and A4/6 were calculated based on these data. The studied soils consisted of strongly and moderately decomposed alder and alder−sedge peat, which contained 309.7−829.0 g/kg of organic matter. The soils were moderately abundant in nitrogen and were characterized by low variability in pH (pHH2O 5.6−6.9). Soil organic matter was dominated by humins, contribution of which ranged from 71.5 to 91.9%. Humic acids constituted 4.9−22.1%, fulvic acids 1.9−6.7% and the most labile organic substances extracted during decalcification of samples (Cdek) – 0.2−1.1% (tab. 2). The observed relatively low degree of humification and quantitative predominance of humic acids over fulvic acids are features typical for riparian organic soils. High values of absorbance ratios of alkaline solutions of humic acids (tab. 3) indicate predominance of aliphatic structures over aromatic in their molecules, which is typical for weakly humified organic substances.
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