Stojące i płynące wody Poznania

Książka zawiera 139 stron, 153 barwne fotografie oraz 135 pozycji literaturyZamiarem autorów tego opracowania było zebranie i przybliżenie czytelnikowi podstawowych wiadomości o jak największej liczbie zbiorników i cieków wodnych, znajdujących się w granicach administracyjnych Poznania. Do przedstawionych danych należy przede wszystkim położenie zbiorników, przebieg cieków wodnych, ich cechy morfometryczne, ale również tam, gdzie to było możliwe – informacje o walorach przyrodniczych, turystyczno-krajobrazowych i o jakości wody. Mają one zachęcić mieszkańców Poznania do odwiedzania opisanych miejsc w ramach wycieczek, spacerów czy choćby po to, by odpocząć od zgiełku ulic miasta i trudów pracy zawodowej. Mają również rozbudzić zainteresowanie otaczającą przyrodą młodzież szkolną, będąc uzupełnieniem wiedzy zdobywanej w ramach zajęć szkolnych.Wydanie książki dofinansowano ze środków budżetowych Miasta Poznani

The Assessment of External and Internal Nutrient Loading as a Basis for Lake Management

Successful management of lake ecosystems used for recreation requires firstly an identification of nutrient sources. It is necessary to identify the factors causing the deterioration of water quality and to plan measures for their mitigation. Analyses of the external and internal nutrient loading were carried out for the hypereutrophic Raczyńskie Lake. The study included flows from lake tributaries, stormwater runoff from impermeable areas and direct catchment impact as external sources of nitrogen and phosphorus, as well as bottom sediments as an internal source of phosphorus. In the case of external sources, the largest load (about 80% of N and 67% of P) is supplied from croplands via the shoreline. Both external and internal loading was characterized by distinct seasonal variability. The loads from watercourses supplying the lake played the most significant role in spring, whereas the release of phosphorus from bottom sediments (accounting for 81.4% of the total P load) was responsible for cyanobacterial blooms in summer. In order to improve Raczyńskie Lake water quality it is crucial to implement both in-catchment and in-lake measures by means of diversion of stormwater runoff, reduction of nutrient content in some of tributaries at their inflow to the lake (gabions filled with dolomite surrounded by macrophytes) and restoration treatments aiming at the inactivation of phosphorus in the water column and reduction of its release from sediments

Functional Groups of Phytoplankton and Their Relationship with Environmental Factors in the Restored Uzarzewskie Lake

Uzarzewskie Lake is a small, postglacial lake, located in western Poland. The lake is under restoration treatment since 2006. At first, iron treatment was done for 2 years. In the second stage, spring water was directed into the hypolimnion in order to improve water oxygenation near the bottom sediments. The purpose of our research was to determine changes in the contribution of functional groups to the total number of taxa and total biomass of phytoplankton due to changes in the physical and chemical characteristics of the restored lake. Phytoplankton composition was analyzed in three periods: (1) before restoration; (2) during the first method of restoration; and (3) when the second method was implemented in the lake. Epilimnetic phytoplankton was sampled every year monthly from March to November. The relationship between phytoplankton groups and environmental factors (water temperature, ammonium nitrogen, nitrate nitrogen, dissolved phosphorus, conductivity and pH) was examined, using the canonical analyses. The redundancy analysis indicated that the temperature, dissolved phosphates concentration, ammonium nitrogen and pH were the main determining factors of the phytoplankton community dynamics. During the study, 13 coda dominated the phytoplankton biomass. Cyanobacteria of the codon H1 with such species as Aphanizomenon gracile, Dolichospermum planctonicum, D. viguieri dominated the phytoplankton community before restoration. S1 group consisting of Planktolyngbya limnetica, Limnothrix redekei and Planktothrix agardhii mostly dominated during the period in which the first method was used. Improvement of water quality due to restoration efforts in the third period caused dominance of other groups, especially J (Actinastrum hantzschii and other Chlorococcales), C (Asterionella formosa and other diatoms), Y (Cryptomonas marssonii and other cryptophytes), Lo (Peridiniopsis cunningtonii and other dinophytes) and X2 (Rhodomonas lacustris)

Sustainable lake restoration: from challenges to solutions

Sustainable management of lakes requires us to overcome ecological, economic, and social challenges. These challenges can be addressed by focusing on achieving ecological improvement within a multifaceted, co-beneficial context. In-lake restoration measures may promote more rapid ecosystem responses than is feasible with catchment measures alone, even if multiple interventions are needed. In particular, we identify restoration methods that support the overarching societal target of a circular economy through the use of nutrients, sediments, or biomass that are removed from a lake, in agriculture, as food, or for biogas production. In this emerging field of sustainable restoration techniques, we show examples, discuss benefits and pitfalls, and flag areas for further research and development. Each lake should be assessed individually to ensure that restoration approaches will effectively address lake-specific problems, do not harm the target lake or downstream ecosystems, are cost-effective, promote delivery of valuable ecosystem services, minimize conflicts in public interests, and eliminate the necessity for repeated interventions. Achieving optimal, sustainable results from lake restoration relies on multidisciplinary research and close interactions between environmental, social, political, and economic sectors

Can space-for-time-substitution surveys represent zooplankton biodiversity patterns and their relationship to environmental drivers?

Space-for-Time-Substitution surveys (SFTS) are commonly used to describe zooplankton community dynamics and to determine lake ecosystem health. SFTS surveys typically combine single point observations from many lakes to evaluate the response of zooplankton community structure and dynamics (e.g., species abundance and biomass, diversity, demographics and modeled rate processes) to spatial gradients in hypothesized environmental drivers (e.g., temperature, nutrients, predation), in lieu of tracking such responses over long time scales. However, the reliability and reproducibility of SFTS zooplankton surveys have not yet been comprehensively tested against empirically-based community dynamics from longterm monitoring efforts distributed worldwide. We use a recently compiled global data set of more than 100 lake zooplankton time series to test whether SFTS surveys can accurately capture zooplankton diversity, and the hypothesized relationship with temperature, using simulated SFTS surveys of the time series data. Specifically, we asked: (1) to what degree can SFTS surveys capture observed biodiversity dynamics; (2) how does timing and duration of sampling affect detected biodiversity patterns; (3) does biodiversity ubiquitously increase with temperature across lakes, or vary by climate zone or lake type; and (4) do results from SFTS surveys produce comparable biodiversity-temperature relationship(s) to empirical data within and among lakes? Testing biodiversity-ecosystem function (BEF) relationships, and the drivers of such relationships, requires a solid data basis. Our work provides a global perspective on the design and usefulness of (long-term) zooplankton monitoring programs and how much confidence we can place in the zooplankton biodiversity patterns observed from SFTS surveys.info:eu-repo/semantics/publishedVersio