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

The diversity of evenness parameter in each sampling date in Maltański Reservoir.

<p>The diversity of evenness parameter in each sampling date in Maltański Reservoir.</p

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

Concentration of nitrogen forms in Maltański Reservoir.

<p>Concentration of nitrogen forms in Maltański Reservoir.</p

The abundance of cladocerans and copepods (an example from the depth of 2 m).

<p>The abundance of cladocerans and copepods (an example from the depth of 2 m).</p

Share of the abundance of zooplankton groups in Maltański Reservoir (an example from the depth of 2 m).

<p>Share of the abundance of zooplankton groups in Maltański Reservoir (an example from the depth of 2 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

A shallow lake in an agricultural landscape – water quality, nutrient loads, future management

Qualitative analyses of nitrogen and phosphorus loads reaching the lake ecosystem provide a basis for pollution control, which is of paramount importance in shallow lakes due to the rapid turn-over of matter and energy. The studies of both external and internal loading were conducted in Lake Łeknenskie, a very shallow, through-flow lake situated in Western Poland. Strong eutrophication is manifested in rich rush vegetation and a lack of submerged macrophytes as well as nitrogen and phosphorus concentrations (max 13.04 mg N dm−3 and 0.32 mg P dm−3, respectively). Constant domination of cyanobacteria in the phytoplankton community was noted in almost all seasons with a 98% share in summer, resulting in 20 cm water transparency and 223 μg dm−3 of chlorophyll-a. The zooplankton community was dominated by rotifers. The main source of nutrients was the River Nielba. Spatial external nutrient loading was 1.93 g P m−2 yr−1 and 77.55 g N m−2 yr−1. An even higher load of phosphorus was released from the bottom sediments, 2.18 g P m−2 yr−1. A comprehensive action plan is required, aiming at the reduction of both external and internal nutrient loading. A series of solutions regarding local environmental conditions should be applied in the lake catchment, including biogeochemical barriers, denitrification walls, artificial retention basins or wetlands, but most of all – improvement in the functioning of the wastewater treatment plant. Restoration is possible, however, protection measures reducing external loading should be undertaken prior to phosphorus inactivation in the water column and in the bottom sediments, supported by biological methods e.g. biomanipulation