Ditches and drainage canals are an important element in the post-bog meadows. Their basic function is to regulate air-water relations in ecosystems, mainly in agrocenoses. The environmental functions of ditches and canals consist of maintaining a large diversity of flora and fauna species due to high humidity of these ecosystems. The study of plant communities in the ditches in the post-bog meadows habitat of the Supraśl Dolna valley structure in 2010–2020 was carried out. There were 23–27 species of plants in the ditches. Species diversity did not change significantly during this period, while changes in individual species’ coverage and viability were found. The species were classified into two rush communities: reed rush ( Phragmitetum australis) and rush ( Phalaridetum arundinaceae). As a result of the lack of maintenance of the ditches, an invasive species of flapped barbed ( Echinocystis lobata) was found. The natural valorization carried out by the Oświt method showed that plant communities in the drainage ditches are in the lowest valorization classes.

A study was conducted on changes in the abundance and diversity of floristic composition in baulks and cultivated agrocenoses in the area of the village of Nowokornino, located on the outskirts of the Białowieża Forest. Within the geodesic area of the village, which covers approximately 1,100 ha, agricultural crops are grown under three farming systems: conventional farming, integrated farming and organic farming. In the study area, there are unique marginal ecosystems in the form of mid-field baulks on which various weed species of ecological importance occur. Three study plots were designated on the baulks, and three plots on field crops Floristic surveys were carried out in 2016, 2020 and 2022. The cover of individual species was estimated according to the 7-level Braun-Blanquette scale. A total of 91 plant species belonging to 6 phytosociological groups were found, with the Stellarietea mediae group having the highest species richness. The significance of differences in floristic richness between study and control plots was tested by one-way analysis of variance (ANOVA). Statistical analysis showed that the factors differentiating the floristic composition on the baulks were their location within the cultivated agrocenoses, natural soil abundance and interaction with fertiliser factors. The highest species abundance of plants defined as weeds, occurred in fields under the integrated farming system (58 species), the lowest in fields under the conventional system (39 species). The vegetation of the baulks and adjacent arable fields was dominated by plants representing mainly three types of ecological strategies: C, R and C-R.