DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 13/2005 str. 217 <-- 217 --> PDF |
1. Tikvić. D. Puntane. 2. Zečić. D. Ugarković, Z. Seletković: TI Ili IMPACT OH MONTANE FOREST Šumarski list SUPLEMENT (2005), 202-218 of forest ecosystems. Indicators of water quality in pro- compared in order to determine the effects of forest tected areas and in commercial forests were finally management on water quality. RESULTS PHYSICAL-CHEMICAL INDICATORS OF WATER QUALITY IN WATERCOURSES Table 2 shows indicators of physical-chemical features of water from the watercourses in the area of Papuk, Plitvice Lakes and Velebit. With regard to pH values, water samples in all the localities belong to the first category (I), except in the locality of Papuk 1, where water bordered between the first and the second category (I and II) (Fig. 1). On average, the lowest pH values were found in the area of Papuk and the highest in the area of Plitvice Lakes. By localities, the highest differences in pH values of water were found in the watercourses of Papuk, and the smallest in the area of Plitvice Lakes (Tabic 2). Values of pH in the watercourses outside the forest ecosystems did not differ significan tly from those in the forests. No differences were found in the pH value of water between protected areas and commercial forests. Electrical conductivity values were the highest in the area of Plitvice Lakes. The majority of the watercourses were in the first (I) water category, except for the localities Plitvice 3 and 4, which were in the second (II) category. The localities Papuk 1 and 2 had significantly lower values of electrical conductivity than other localities. Higher electrical conductivity values were found in the protected area in relation to commercial forests, while no differences were found between the localities in and outside the forest. OXYGEN REGIME IN WATERCOUSES No differences were found between the localities in terms of dissolved oxygen values, oxygen saturation and chemical requirements of oxygen, except for the locality Papuk 2, which showed considerable aberration from these indicators in relation to other localities. In terms of dissolved oxygen, all watercourses contained the first-category water (I), except for the sample from the river Orljava (Papuk 2). Oxygen saturation in the area of Papuk was slightly lower and in Plit vice Lakes slightly higher, so three samples had water quality of the second category (II) (Fig. 2). Chemical oxygen consumption (COC) was similar in all the watercourses, except for the sample from the river Orljava, where COC values were 30 times higher than those in other Papuk localities (Table 2). Higher COC values indicate an increased content of hardly soluble organic matter in water. No oxygen regime indicators were measured in the area of Velebit. NUTRITIVE AND ORGANIC MATTER AND MICROBIOLOGICAL INDICATORS OF WATER QUALITY IN WATERCOURSES Nitrates are the only nutrients found in water samples from the watercourses. In terms of nitrate content, the majority of the watercourses belonged to the second category (II), except for the locality Velebit 1 and 3, whose waters were in the first category (I) (Table 3). No differences were found between the protected area and commercial forests, nor were they found between watercourses in and out of forests. The average proportion of aerobic bacteria was the lowest in Plitvice Lakes, slightly higher on Papuk and the highest on Velebit. All aerobic bacteria values were within the first-category water, except the river Orljava (Papuk 2), where the quantity of aerobic bacteria exceeded that in other watercourses by up to 250 times. No differences were found between the protected area and commercial forests, whereas a significantly higher quantity of aerobic bacteria was found in the watercourses outside the forests compared to those in the forests. The mineral oil content in the majority of the samples was within the limits of the first-category water. Only the samples from the Orljava (Papuk 2) and the stream Veliki Tisovac (Velebit 4) had water of the second category. Higher values of total oil quantities were found in the watercourses outside the forests in relation to those in the forests. Minimal values were found in the watercourses on Velebit and on Papuk (Fig. 4). No differences in the quantity of mineral oils and total oils were established between protected areas and commercial forests. DANGEROUS SUBSTANCES AND METALS IN THE WATERCOURSES OF MONTANE CROATIA In terms of cyanide content, water in the majority of the watercourses belonged to the second category (II). The least cyanide was registered in Plitvice Lakes, while the most was found on Velebit. Velebit also sho wed the highest differences between particular watercourses in the same area. In terms of cyanide content, higher cyanide concentrations were found in commercial forests compared to those in the protected area, |