The body size distribution of Filinia longiseta (Ehrenberg) in different types of small water bodies in the Wielkoposka region

The body size distribution of Filinia longiseta (Ehrenberg) in different types of small water bodies in the Wielkoposka region Small water bodies are often characterised by speci c macrophyte species composition and different levels of predation. This may also have an effect on the body size and shape of rotifer specimens. The aim of the study was to determine the relation of the size of rotifer Filinia longiseta (body and appendages length), with respect to three speci c kinds of pond (mid-forest, pastoral and anthropogenically changed) and to three kinds of hydromacrophytes (nymphaeids, elodeids and helophytes) as well as comparatively to the open water zone. The examined water bodies also differed in sh presence or absence. Morphometric analysis of specimens of F. longiseta showed that both factors –the type of water body relating to different land-use in the catchment area as well as the microhabitat type– were signi cant predictors, in uencing their body size and spine length. Filinia longiseta specimens were signi cantly smaller in ponds situated within the pastoral catchment area. The largest specimens were found among stands of nymphaeids, while the smallest were found within the open water zone, which may indicate both the ecological requirements of this species as well as the marked in uence of sh in the unvegetated area.Distribuci´on de tama˜nos de Filinia longiseta (Ehrenberg) en diferentes tipos de peque˜nas masas de agua en la regi´on de Wielkoposka Las peque˜nas masas de agua est´an caracterizadas a menudo por la composici´on espec´ ca de macr´o tos y diferentes niveles de depredaci´on. Esto puede tener efecto en el tama˜no y la forma de los rot´ feros. El objetivo de este estudio fue determinar las diferencias de tama˜no (longitud del cuerpo y de los ap´endices) del rot´ fero Filinia longiseta en tres tipos de charcas (forestales, de pastizales y antropizadas) y en tres tipos de vegetaci´on sumergida (ninfeidos, elodeidos y hel´o tos) as´ como tambi´en en aguas libres. Las charcas examinadas difer´ an tambi´en por la presencia o no de peces. Los an´alisis morfom´etricos de los individuos de F. longiseta han mostrado que tanto el tipo de charca, seg´un los usos del suelo en el ´area de captaci´on, como el tipo de microhabitat in uencian las longitudes del cuerpo y de los ap´endices. Los individuos de F. longiseta resultaron ser signi cativamente m´as peque˜nos en las charcas situadas en las zonas de pastizales. Las poblaciones con individuos de mayor tama˜no se encontraron en las matas de ninfeidos, mientras que en las de aguas libres se encontraba las constituidas por individuos de menores dimensiones, lo que puede ser debido tanto a las adaptaciones de esta especie a las condiciones del medio como a la reconocida in uencia de los peces en las zonas desprovistas de vegetaci´on

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

Vertical distribution of zooplankton in a shallow peatland pond: the limiting role of dissolved oxygen

We investigated the diel vertical distribution patterns of microcrustacean zooplankton (Cladocera, Copepoda) in a shallow pond (max. depth: 70 cm) of the Öreg-turján peatland (Ócsa, Central Hungary) during three 24-h periods in July (19–20th), August (17–18th) and September (11–12th) 2011. Environmental variables showed remarkable vertical stratification. Oxygen concentration was close to zero in the entire water column from night until sunrise, while the lower strata (from 20 cm below the surface) were close to anoxic during all three diel cycles. It proved to be the main determinant of the vertical distribution of microcrustaceans. Accordingly, the highest proportion of individuals was present in the surface layer. Chlorophyll-a concentration and phytoplankton biomass were inversely distributed compared to zooplankton. Microcrustaceans (mainly Daphnia curvirostris) migrated to the middle layer only in August, which could be explained by a trade-off between food resources, dissolved oxygen (DO) and competition with littoral zooplankters. The diurnal density patterns of microcrustaceans suggested horizontal migration into the aquatic macrophytes during night, which could be a strategy to avoid Chaoborus predation. Our results show that strong vertical gradients of abiotic and biotic factors occur even in such shallow waterbodies. Among them, DO can maintain constant vertical aggregation of zooplankters by limiting their occurrence to the surface layers

Abundance, biomass and community structure of pond phytoplankton related to the catchment characteristics

Studies were conducted in 2010 on phytoplankton assemblages in ponds in North-East Poland with catchment areas in village environments, mid-forest, mid-meadow and mid-field settings. Differences in phytoplankton abundance, biomass and structure and the environmental requirements of dominant species were assessed in the studied ponds. These features were related to variable physicochemical water parameters and nutrient presence; with the highest phytoplankton abundance and biomass dominated by chlorophytes and diatoms in the village ponds and the greatest diversity of species’ assemblages recorded in the mid-forest and mid-field ponds. In addition, CCA analysis of general trends in phytoplankton growth determined that NH4 and TN enhanced growth in the mid-meadow and mid-field ponds, and P-PO4 and pH influenced growth in the mid-forest pond. The relationships established in this study between phytoplankton and environmental conditions can directly influence future directions in small water-body conservation

The response of phytoplankton, zooplankton and macrozoobenthos communities to change in the water supply from surface to groundwater in aquaculture ponds

Investigating forces driving the structure of aquatic communities has long been an important issue in ecology. In the present study, we focused on the effects of changed water supply for aquaculture ponds on phytoplankton, zooplankton and macrozoobenthos communities during two seasons of rearing common carp. We compared these communities between two types of inflow water: surface sources of water a reservoir pond, two open wells and a small stream and groundwater deep tube well. Significant changes were observed in environmental variables after the introduction of the groundwater source: oxygen concentration and water hardness decreased, while conductivity, phosphorus and un-ionized ammonia increased. Results revealed that all investigated groups, except Mollusca (macrozoobenthos), decreased in species richness, abundance and biomass due to changed water chemistry, but differed in the level of susceptibility. Rotifera and Cladocera were the most affected showing a sharp decline in density and number of species since 66% of species disappeared from the ponds. The abundance of Copepoda was relatively high although significantly lower under new conditions, with adults being more tolerant to changed inflow water than nauplii larvae. Phytoplankton had the highest potential to replace previous species with newcomers more adapted to changed water chemistry, providing 36 immigrant species, whereas 49 became extinct. Although mainly influenced by fish predation, Chironomidae (macrozoobenthos) were undoubtedly affected by changed water chemistry. These results suggest profound changes in three key ecological groups produced by significant changes of important environmental variables and water quality after the shift from surface to groundwater supply

Epiphytic metazoans on emergent macrophytes in oxbow lakes of the Krapina River, Croatia: differences related to plant species and limnological conditions

This study investigated the structure of the epiphytic metazoans on emerged macrophytes in the littoral zone of two oxbow lakes with different trophic levels. Differences in the diversity and density of the epiphytic metazoans were analyzed in relation to plant architecture (simple or complex stems), food resources (algae and detritus) and water characteristics (transparency and derived trophic state index). Asignificant negative correlation was found between detritus on plants as food resource, and diversity and density of epiphytic metazoans, indicating grazing of microphagous species. Rotifers dominated in diversity and density in the epiphyton on all habitats. Total density of metazoans, rotifers and copepods in epiphyton were significantly higher on Mentha in mesotrophic lake than on Iris in a eutrophic lake.We presume that macrophyte belt width and trophic state governed biotic interactions and consequently epiphytic assemblages more strongly than macrophyte architecture. However, a Mentha habitat showed a slightly higher density and diversity of epiphytic metazoans in relation to Iris at the same site, but these differences were not significant

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

Response of Zooplankton Indices to Anthropogenic Pressure in the Catchment of Field Ponds

As methods for assessing the environmental conditions in ponds are still not well developed, I studied zooplankton to identify a response of community indices to abiotic, biotic, and habitat type in two types of ponds differing in the level of human stress. Ponds of low human alterations (LowHI) harbored generally richer communities and a higher share littoral zooplankton, whose occurrence was associated with higher water transparency and complex macrophyte habitat, particularly the presence of hornworts and charoids. In high human-impact ponds (HighHI) planktonic communities prevailed. Their distribution was mainly related to the open water area and fish presence. Anthropogenic disturbance was also reflected in the frequency of rare species, which were associated with LowHI ponds. Higher diversity of zooplankton increased the chance for rare species to occur. Despite the fact that the majority of rare species are littoral-associated, they had no prevalence towards a certain ecological type of plants, which suggests that any kind of plant cover, even macrophytes typical for eutrophic waters (e.g., Ceratophyllum demersum) will create a valuable habitat for conservation purposes. Thus, it is postulated that a complex and dense cover of submerged macrophytes ought to be maintained in order to improve the ecological value of small water bodies