Abstract Coleanthus subtilis is a globally rare therophyte growing on exposed bottoms of water reservoirs and riverbanks, where it forms dense patches, while specimens differ morphologically within the population. However, factors determining its morphological variability and habitat features favoring its good performance remain poorly understood. Also, despite the fact that it is threatened in many regions, it shows a potential to conquer new localities, especially anthropogenic habitats, and dominate in some phytocoenoses. Therefore, we analyzed in detail the main morphological features of the species in relation to bottom sediment characteristics, i.e. pH and macroelement content and ecological preferences, illustrated by the values of ecological indicators, and phytocoenoses composition. We showed that pH, N and P content, as well as the moisture of the bottom sediments determine the intrapopulational morphological variability of C. subtilis . Different morphotypes can co-occur in one vegetation patch, but one morphological type usually prevails depending on bottom sediment characteristics, and the coverage of individuals of other plant species, as well as the C. subtilis itself. Our results show the link between C. subtilis morphotypes and habitat parameters, and shed light on the relationship between its morphotypes and the coverage of individuals of various species comprising vegetation patches, which can be considered in management and conservation of this species.

Abstract Urban wetlands, though frequently underestimated, contribute to biodiversity in cities and enhance residents’ well-being. However, these ecosystems have faced significant threats and degradation over the past century due to urbanization and unsustainable land-use changes, leading to significant biodiversity loss and ecosystem services. This study examines a comparative analysis of urban wetland policies in Helsinki, Finland, and Vienna, Austria, with a focus on governance structures, planning frameworks, and the role of institutional actors and policymakers in wetland conservation. Building on previous research that identified policy neglect in Helsinki’s wetlands, this study examines the policy-making processes in both cities to identify barriers and opportunities for improving urban wetland management. Through expert interviews and policy documents, the study explores how governance dimensions shape wetlands in both cities. Based on the analysis, the research identifies similarities and differences in how both cities approach wetland protection. The findings emphasize the importance of cross-sectoral collaboration and long-term urban ecological planning. The study concludes with practical recommendations to support sustainable wetland protection in the face of urban development and climate change, offering solutions that may also be applicable to other urban contexts. Ultimately, this work aims to contribute to more resilient urban ecosystems and the long-term protection of wetland biodiversity and functionality.

Abstract The vegetation of high Andean wetlands in hyperarid environments is typically azonal; however, differentiated responses between permanent and temporary vegetation cover have been observed, driven by environmental factors. These responses create dynamic boundaries in vegetation cover, complicating the monitoring, assessment, and management of wetlands. Using the Tilopozo wetland as the study area, we aimed to identify permanent vegetation cover and evaluate its stability over time and determine changes in temporary vegetation cover and the environmental factors that influence them. The surface covered with vegetation was analyzed using six time-series from 1985 to 2019 based on the normalized difference vegetation index. The stability of permanent vegetation cover was assessed using the Kappa coefficient, while temporary vegetation cover was correlated with environmental factors (precipitation, evapotranspiration, and water table levels). Vegetation maps were used to determine the dominant species for both types of cover. The results revealed that permanent vegetation exhibited high temporal stability, with Kappa coefficients ranging from “very good” to “excellent,” dominated by Schoenoplectus americanus and Baccharis juncea , two strict hygrophilous species. Conversely, temporary vegetation cover was significantly influenced by precipitation and evapotranspiration and composed of transitional hygrophilous species such as Distichlis spicata and Tessaria absinthioides . These findings present an approach to delineate stable boundaries and estimate the maximum potential extent of wetlands (dynamic boundaries), and assessing their spatiotemporal variability and the environmental drivers of these changes. This information is crucial for the effective management and conservation of wetland ecosystems in these environments.

Abstract New definitions of “niche diversification” and “niche differentiation” are proposed. The former is the opening up of new adaptive zones through major changes in the environment or though internal changes that allow a range of new resources to be exploited. The latter is the lowering of competition (both intra- and interspecific) within existing adaptive zones through partitioning of resources. These definitions are discussed with respect to Hutchinson’s n-dimensional concept of the niche. The snail-killing flies (Sciomyzidae: Diptera), one of the biologically best known and most species rich higher flies in wetlands, are used as exemplars of this concept.