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

Response of vegetation to growing recreational pressure in the shallow Raczyńskie Lake

Strong human impact accelerates eutrophication which deteriorates water quality and consequently prevents recreational use. Increasing trophy and low transparency induce macrophyte rebuilding. A gradual transformation of the land use of the direct catchment area of Raczyńskie Lake from agricultural to recreational has been observed over the last 45 years. In built-up areas sewage facilities were inadequate and septic tanks did not work properly and as a consequence most wastewater was able to infiltrate through the ground into the lake. The lake ecosystem became unstable and water blooms intensified. The aim of the study was to assess the changes in the composition of the lake vegetation over the last 45 years, during which the use of the direct catchment has changed and recreational pressure increased. A reduction of the number of plant communities from 24 to 15 and the disappearance of almost all the submerged vegetation was observed. The dominant reed beds (Phragmitetum communis, Typhetum angustifoliae) were unable to provide a sufficient barrier to the flow of pollution from the catchment because of the numerous gaps made for angling piers, bathing sites, jetties, etc. The macrophyte index indicated a bad ecological status. To improve the ecological status of Raczyńskie Lake it is necessary to introduce intensive protection and restoration treatments

Response of vegetation to growing recreational pressure in the shallow Raczyńskie Lake

Strong human impact accelerates eutrophication which deteriorates water quality and consequently prevents recreational use. Increasing trophy and low transparency induce macrophyte rebuilding. A gradual transformation of the land use of the direct catchment area of Raczyńskie Lake from agricultural to recreational has been observed over the last 45 years. In built-up areas sewage facilities were inadequate and septic tanks did not work properly and as a consequence most wastewater was able to infiltrate through the ground into the lake. The lake ecosystem became unstable and water blooms intensified. The aim of the study was to assess the changes in the composition of the lake vegetation over the last 45 years, during which the use of the direct catchment has changed and recreational pressure increased. A reduction of the number of plant communities from 24 to 15 and the disappearance of almost all the submerged vegetation was observed. The dominant reed beds (Phragmitetum communis, Typhetum angustifoliae) were unable to provide a sufficient barrier to the flow of pollution from the catchment because of the numerous gaps made for angling piers, bathing sites, jetties, etc. The macrophyte index indicated a bad ecological status. To improve the ecological status of Raczyńskie Lake it is necessary to introduce intensive protection and restoration treatments

Water Quality of Freshwater Ecosystems in a Temperate Climate

Water is the substance that made life on Earth possible. It plays a key role in both the individual and population development of all species. Water is also a critical resource for humans as populations continue to grow and climate change affects global and local water cycles. Water is a factor limiting economic development in many regions of the world. Under these conditions, good water quality becomes an extremely important factor that determines its economic utility, including water supply, recreation, and agriculture. Proper water quality maintenance of freshwater ecosystems is also very important for preserving biodiversity. The quality of water depends on many factors, the most important of which are related to human impact on water ecosystems, especially the impact of various pollutants from municipal economy, industry and agriculture. Hydrotechnical changes, such as river damming, drainage processes and water transport between catchments also have a significant impact. Water quality is also dependent on the impact of natural conditions connected, e.g., with climate, catchment, water organisms and their interactions within the food-webs, etc. This Special Issue consists of fourteen original scientific papers concerning different problems associated with the water quality of freshwater ecosystems in a temperate climate. Most of the articles deal with the relations between water quality and the structure of ecosystem biocenoses. The conclusion of these articles confirms the fact that the deterioration of water quality has a direct impact on the quantitative and qualitative structure of biocenoses. This is accompanied by a decline in biodiversity and the disappearance of rare plant and animal species. They also draw attention to the particular importance of internal physical and chemical differentiation within the aquatic ecosystem, both in horizontal and vertical dimensions. The problem of ensuring proper ecological conditions and good quality of water in freshwater aquatic ecosystems is also raised, and methods for the restoration of water bodies are presented. The majority of the research presented in this Special Issue was carried out in Central Europe, and one of the papers concerns the area of West Africa—the edge of temperate climate zone

Numerical criterion for the duration of non-chaotic transients in ODEs

The paper proposes an original numerical criterion for the duration analysis of non-chaotic transients based on the Euclidean norm of a properly defined vector. For this purpose, transient trajectories, prior to their entering a small neighbourhood of the limit cycle, are used. The vector has been defined with its components constituting the lengths of the sections, which connect the origin of the coordinate system with appropriately determined transient trajectory points. The norm of the vector for the analysis of non-chaotic transients has also been applied. As an assessment criterion of transients, the convergence of the norm to small neighbourhood of the limit cycle with the assumed accuracy is used. The paper also provides examples of the application of this criterion to the Van der Pol oscillators in the case of periodic oscillations

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

Ryby w kulturze i rekultywacja środowiska wodnego. Szkic historyczny i badania hydrobiologiczne

Opracowania w książce bogato ilustrowaneW części pierwszej książki, autorstwa Andrzeja M. Wyrwy, przez pryzmat źródeł archeologicznych, historycznych, etnograficznych i ikonograficznych, w syntetycznej formie, zasygnalizowano wybrane wątki odnoszące się do miejsca ryb w kulturze, ich symboliki w życiu ludzi zachodnioeuropejskiego kręgu kulturowego i diecie rybnej zakonników różnych obserwancji od średniowiecza do czasów nowożytnych. W części drugiej znajdują się rozważania poświęcone rekultywacji środowiska wodnego. Obecnie stało się bowiem tak, że w wyniku zdynamizowanej, nie zawsze do końca przemyślanej działalności człowieka, a jednocześnie naturalnych zmian środowiska, ów życiodajny, szanowany i czczony przez tysiąclecia dar coraz bardziej jest niszczony. Stąd też jednym z ważniejszych działań jest obecnie potrzeba ochrony wód z całym ich bogactwem. Tym zagadnieniom poświęcone są dwa opracowania w książce. Ryszard Gołdyn omawia metody rekultywacji i poprawy stanu jakości wód, a Beata Messyasz, Katarzyna Kowalczewska – Madura, Sławomir Cerbin poddają ocenie skuteczność rekultywacji wód na przykładzie Jeziora Durowskiego

The biomass of phytoplankton groups in the investigated period (an example from the depth of 1 m).

<p>The biomass of phytoplankton groups in the investigated period (an example from the depth of 1 m).</p

RDA biplot showing relationships between phytoplankton size fractions (a), taxonomical groups (b), the most abundant taxa and selected environmental factors directly dependent on restoration measures (c).

<p>Abbreviations: cond-conductivity, ON-organic nitrogen, oxy-oxygen saturation, temp-temperature, R+n—rotifers and nauplii, FILT- filter feeders, PRED- predators, nono- nanophytoplankton, micro-microphytoplankton, <i>Aph</i>.<i>gra</i>.<i>-Aphanizomenon gracile</i>, <i>Ast</i>.<i>for</i>.<i>-Asterionella formosa</i>, <i>Aul</i>.<i>gran</i>.<i>-Aulacoseira granulata</i>, <i>centr- centric diatom</i>, <i>Chr</i>.<i>min</i>.<i>-Chrysococcus minutus</i>., <i>Chl</i>.<i>sp</i>.<i>-Chlamydomonas sp</i>., <i>Coe</i>.<i>ast</i>.<i>- Coelastrum astroideum</i>, <i>Cry</i>.<i>mar</i>.<i>- Cryptomonas marssonii</i>, <i>Cry</i>. <i>ova</i>.<i>- Cryptomonas ovata</i>, <i>Cry</i>.<i>ref</i>.<i>- Cryptomonas reflexa</i>, <i>Cus</i>.<i>iss</i>.<i>-Cuspidothrix issatschenkoi</i>, <i>Cru</i>. <i>tet</i>.<i>- Crucigenia tetrapedia</i>, <i>Des</i>.<i>com</i>.<i>- Desmodesmus communis</i>, <i>Des</i>.<i>opo</i>.<i>- Desmodesmus opoliensis</i>, <i>Din</i>.<i>div</i>.<i>- Dinobryon divergens</i>, <i>Erk</i>.<i>sub</i>.<i>-Erkenia subaequiciliata</i>, <i>Fra</i>.<i>cro</i>.<i>-Fragilaria crotonensis</i>, <i>Kol</i>.<i>spi</i>.<i>-Koliella spiculiformis</i>, <i>Lim</i>.<i>red-Limnothrix redekei</i>, <i>Mon</i>.<i>con</i>.<i>-Monoraphidium contortum</i>, <i>Mon</i>. <i>min</i>.<i>- Monoraphidium minutum</i>, <i>Nit</i>.<i>aci</i>.<i>- Nitszchia acicularis</i>, <i>Nit</i>.<i>clo</i>.<i>- Nitszchia acicularis var</i>. <i>closterioides</i>, <i>Nit</i>. <i>spp—Nitszchia spp</i>., <i>Ooc</i>.<i>lac</i>.<i>- Oocystis lacustris</i>, <i>Ped</i>.<i>bor</i>.<i>- Pediastrum boryanum</i>, <i>Pha</i>.<i>lent</i>.<i>- Phacotus lenticularis</i>, <i>Pla</i>.<i>aga—Planktothrix agardhii</i>, <i>Rho</i>.<i>lac</i>.<i>- Rhodomonas lacustris</i>, <i>Sce</i>.<i>acu</i>.<i>- Scenedesmus acuminatus</i>, <i>Syn</i>.<i>uve</i>.<i>- Synura uvella</i>, <i>Uln</i>.<i>acu</i>.<i>- Ulnaria acus</i>.</p