The aim of the study was to identify the vegetation pattern in the different types of watercourses basing on survey in reference conditions in a wide geographical gradient, including mountain, upland and lowland rivers. We tested relationship between composition of macrophytes to environmental variables including: altitude, slope, catchment area, geology of valley, land use, hydromorphological features, water physical and chemical measurements. Analysis based on 109 pristine river sites located throughout major types of rivers in Central Europe. Qualitative and quantitative plant surveys were carried out between 2005 and 2013. Based on TWINSPAN classification and DCA analysis, six macrophyte types were distinguished. The lowland sites were divided into the following three types: humic rivers and two types of siliceous rivers depending on the catchment area, including medium-large and small rivers. The mountain and upland rivers were divided into three geological types: siliceous, calcareous and gravel. We found that the variation of macrophyte communities was determined by several habitat factors (mainly altitude, flow type, riverbed granulometry, conductivity and alkalinity), whereas the spatial factor was rather limited; further, the plant diversity was not reflected accurately by the European ecoregion approach.

The aim of the study was to compare the patterns of development of macrophytes and macroinvertebrates in different types of reference mountain rivers. The study is based on reference river sites surveyed throughout the mountains in Poland and Slovakia in two European ecoregions (9—Central Highlands, 10—The Carpathians). A wide range of environmental variables were estimated, including water chemistry, hydromorphology, geology, and the spatial factor. Based on the Jaccard index, macrophyte and macroinvertebrate variation was confirmed between four mountain and upland river types. It was found that the biological diversification is mainly influenced by geological and associated chemical factors. In the case of macroinvertebrates, additionally, the importance of the spatial factor was revealed (difference between ecoregions). Finally, the habitat preferences of various taxa were identified. It was found that extreme mountain conditions can sometimes distort bioindicative response, as was detected in the case of macroinvertebrates in the highest mountain sites. We concluded that consideration of two groups of organisms enables more comprehensive and reliable monitoring than assessment based on a single group, especially when standard bioindicative methods can be distorted by extreme local conditions.

In several countries around the world, agricultural land area exceeds 70% (Uruguay 82.6%, Kazakhstan 80.4%, Turkmenistan 72.0%, Great Britain 71.7%, Ukraine 71.6% and others). This poses a serious risk of dissipating nitrates into the aquatic environment in agricultural catchments. The aim of this study was to assess the impact of land use on water quality parameters in an agricultural catchment area. It was decided to select for analysis the catchment of the Orla River (river length of 88 km, catchment area of 1,546 km²). The catchment area is predominantly agricultural in character and its entire area has been declared as an agricultural nitrate vulnerable zone (NVZ). A total of 27 survey sites were selected on the main watercourse and its tributaries. Analyses were conducted in the years 2010–2012 to determine physical and chemical parameters of water (pH reaction, conductivity, dissolved oxygen, total nitrogen, organic nitrogen, ammonia nitrogen, nitrates, total and reactive phosphorus) as well as six macrophyte metrics of ecological status assessment (MIR, IBMR, RMNI, MTR, TIM, RI). The average values of most physico-chemical parameters of water quality repeatedly exceeded limits of good ecological status, both in the Orla River and its tributaries. As many as 18 survey sites were classified as moderate ecological status, five sites as poor and only four as good ecological status. The results indicate the impact of land use in the catchment on water conductivity. Differences were observed in the concentrations of biotic components in the main watercourse and its tributaries, and in water quality in the southern part of the catchment in relation to the rest of the study area. This is probably connected with a greater share of forests and surface waters in that area.

Currently, one of the most serious threats to the environment in rural areas is industrial livestock production, which generates a significant amount of chemical and biological pollution. It causes pollution of waters, affects biodiversity, and has an impact on the climate. Research was carried out in the Orla River (Poland) with a catchment area of 1.546 km². Studies were concentrated on pH, dissolved oxygen, alkalinity, and other factors. Analyses were conducted on the area of livestock buildings in two buffer zones, 1 and 3 km wide, respectively, and included the abundance of phosphorus and potassium in soil as well as its potential impact on the quality of river water. Seasonal variability was observed for nutrients. In the winter period the highest concentrations of nitrates were observed, while in the summer this was the case for phosphates and total phosphorus. The highest concentrations of nutrients occurred in 2012, particularly total and ammonium nitrogen. There was a positive correlation between livestock building area and parameters such as ammonium, organic, and total nitrogen in the 1 km buffer, as well as organic and total nitrogen, potassium and dissolved oxygen in the 3 km buffer. Negative correlation in the case of pH was observed in both buffer zones. Relationships were found between the area of livestock buildings and parameters analyzed during seasons.

Changes of nutrient concentrations in water sensitive to nitrate pollution from agricultural sources in the Samica Stęszewska river catchment. The aim of this study was to evaluate the surface water quality during the first period of measures undertaken to reduce nitrate concentrations in the nitrate vulnerable zone. The study was carried out in the upper part of the Samica Stęszewska catchment, located in the Wielkopolska region (western Poland), designated by the nitrate directive as a nitrate vulnerable zone (Nitrate Directive 91/676/EC). Water samples were taken at nine control points from February 2003 to December 2007. The results indicate that nitrate pollution reduction measures taken in the nitrate vulnerable zones were ineffective in reducing this type of pollution. Water quality was poor at almost all of the monitoring points, and based on nitrate concentrations, water quality was classified in classes IV or V. The only exception was in the outflow from Lake Niepruszewskie, where water quality was classified as either class I, II or III. Also water quality in Lake Niepruszewskie was extremely eutrophic. Our results indicated a role of Lake Niepruszewskie as a nutrient sink reducing pollution from the catchment.

The increasing demand for food and animal products makes it important to ensure that animals have sufficient fodder obtained from grassland. Unfortunately, there has been a recent decline in grassland areas, which makes it essential to find solutions to increase the grassland’s productivity and the quality of the fodder it yields. One of these solutions may be the use of appropriate irrigation and fertilization. The present study investigated the effect of the foliar application of silicon fertilizer and the groundwater level in a subirrigation system on the yield of a three-cut meadow. Four different experimental plots were used: high groundwater level (HWL), high groundwater level with silicon application (HWL_Si), lower groundwater level (LWL), and lower groundwater level with silicon application (LWL_Si). The analyses showed that silicon significantly reduced the amount of dry matter obtained in each of the three meadow cuts during the year. Furthermore, the plot with a higher groundwater level had an annual yield of 12.69 Mg·ha⁻¹, whereas when silicon was applied to this area, it was 10.43 Mg·ha⁻¹ (17.8% reduction in dry matter). A similar trend was noted at lower water levels, in which silicon also caused a dry matter reduction. However, the experiment did not indicate a statistically significant effect of silicon application on plant height and NDVI values. These results show that further research is still needed to better understand silicon’s effect on meadow sward.