The study aimed at estimating the reliability of river classification based on macrophytes under differentiated habitat conditions. The studies were carried out between 2002 and 2005, within the EU STAR project and two other local projects. Factors taken into consideration included: shading, habitat modification, and lengths of the survey sections. Polish lowland watercourses were surveyed. The analyzed streams represented a wide range of degradation. Several macrophyte-based metrics were evaluated, including major European systems (MTR, IBMR, TIM, MI, RI) and diversity metrics (number of species, Shannon diversity index, total cover). The reaction of the macrophyte-based metrics examined to habitat factors was compared. It was proved that some of the metrics appeared to be resistant to different sources of variability, thus confirming their usefulness for river monitoring.

Financial liquidity and profitability are two critical phenomena present in the financial economy of a company, whose relations depend on each other and may course in different directions. At the same time, they are an example of the complexity of the problem, which demands a proper approach, allowing one to reconcile two opposing objectives of any enterprise, i.e., maximizing the benefits for the owners and minimizing the risk of losing financial liquidity. Until now, the relationship between liquidity and profitability has not been examined explicitly, using multidimensional methods in particular. Nevertheless, the links between profitability and financial liquidity maintenance ensure the sustainable development of enterprises in different branches. This paper formulates two aims: scientific and practical. The scientific one concerns adopting the canonical variate analysis method to visualize the differences and relationships between food industry companies regarding financial liquidity and profitability. The practical one relates to indicating the relationship between financial liquidity and profitability in different groups of food industry companies. To study the relationships between the selected groups of enterprises and describe them, the liquidity and profitability ratios were utilized, involving canonical variate analysis based on transformation by linear combination and singular value decomposition. The analysis found that the most important feature highlighting the group of the examined entities regarding financial liquidity was the cash conversion cycle. The research results showed the existence of multidirectional relationships between liquidity and profitability. The research indicates that they depend on indicators describing financial dependencies and the industries in which they operate. This led to a much deeper and broader interpretation of the assessment of the financial situation of companies to support their sustainable development.

Wielkopolska region has precipitation below country average and water shortage is especially visible during spring and summer, thus regeneration of water bodies play important role in saving of water reserves in rural areas. The newly built water reservoir is located in Nienawiszcz, Rogoźno commune, Poland. The aim of study was to compare experimental sites according to parameters describing water trophy like chlorophyll a, dry mass of seston, total organic carbon, biochemical oxygen demand and according to concentrations of nitrogen and phosphorus compounds. Sites were compared using location in reservoir and year season. In the year 2014 (after connection of both parts of lake) part A and B of reservoir had similar trophic conditions, thus confirming stabilisation of the reservoir as an initial freshwater ecosystem. Water table level was also stable, thus low average water depth was not affected water quality Based on canonical variates analysis it was showed, that changes of nitrates and total nitrogen concentrations strongly affected the variability of experimental objects in comparison to concentrations of nitrites and total phosphorus. In the year 2014, after connection of both parts A and B the reservoir start to stabilise in case of similarity of water quality parameters in surveyed sites.

In conditions of economic and political instability, when unpredictability affects business, the need for security, including financial security, becomes particularly important. In our study, we address this issue, with the main objective of comparing and evaluating the financial security of small and medium-sized renewable energy companies in Poland according to sustainable development goals. In order to study and describe relationships between selected groups of companies, financial ratios were used, including canonical variate analysis. The liquidity ratios of the surveyed companies indicated a low level of financial security in terms of the ability to meet short-term liabilities. The profitability of operations was low and did not contribute to the improvement of financial security in most of the companies. The lowest return on assets was found in the group of biogas plants. Higher profitability of assets was found in solar power plants, including those with system installations. Solar power plants were also characterized by a high level of total debt and a rapid turnover of assets in comparison to other studied companies. The results show that the financial security of small and medium-sized renewable energy enterprises in Poland is low, which may be a threat to sustainable development in the future.