Szymon Jusik

Assessment of sources of uncertainty in macrophyte surveys and the consequences for river classification

The application of macrophytes in freshwater monitoring is still relatively limited and studies on their intercalibration and sources of variation are required. Therefore, the aim of the study was to compare selected indices and metrics based on macrophytes and to quantify their variability. During the STAR project, several aspects influencing uncertainty in estimation of the ecological quality of river were assessed. Results showed that several metrics based on the indicative value of plant species can be used in evaluation of the ecological status of rivers. Among estimated sources of variance in metric values the inter-surveyor differences had the lowest effect and slightly stronger were the influences of temporal variation (years and seasons) and shading. The impact of habitat modification was the most important factor. Analysis showed that some of macrophyte-based metrics (notably MTR and IBMR) are of sufficient precision in terms of sampling uncertainty, that they could be useful for estimating the ecological status of rivers in accordance with the aims of the Water Framework Directive.

Macrophyte development in unimpacted lowland rivers in Poland

Freshwater classification according to the Water Framework Directive (WFD) is based on estimation of the deviation between biological elements found on river stretch in comparison with communities detected in the same river type under reference conditions (undisturbed and near-natural habitats). We present analyses to describe macrophyte development in pristine lowland rivers and to reveal the variation among various stream types. The study is based on a country-wide survey of Poland with a dataset of 642 sites on 367 water courses. Surveyed rivers covered the whole lowland area of Poland. Field surveys were conducted using the Polish macrophyte approach, which enabled calculation of several macrophyte metrics. Firstly, a numerical index MIR (Macrophyte Index for Rivers) was computed, which reflects river degradation, especially eutrophication. Furthermore, five diversity metrics were calculated. Each survey, in addition to macrophyte assessment, was supplemented by a complex suite of environmental records. Reference conditions were defined using four criteria: (1) catchment land use, (2) hydromorphological features, (3) water quality and (4) biological assessment. The selected reference lowland rivers included 40 sites. To classify plant data, two-way indicator species analysis Twinspan was used. This resulted in distinguishing four end-clusters which were heterogeneous according to plant composition: organic rivers and three types of siliceous rivers (small with sandy substrate, small with stony substrate and large rivers). The differentiation of environmental factors between river types was confirmed by a variance analysis (ANOVA). Furthermore, the environmental database was explored with principal component analysis (PCA). The PCA principal components were analysed against river types with the canonical correspondence analysis (CCA). Finally botanical differences between identified river types have been detected, using botanical metrics the share of different macrophyte groups and relationships with particular species were defined.

The variability of macrophyte metrics used in river monitoring

The variability of macrophyte metrics used in river monitoring The study aimed at estimating the reliability of river classification based on macrophytes under differentiated habitat conditions. The studies were carried out between 2002 and 2005, within the EU STAR project and two other local projects. Factors taken into consideration included: shading, habitat modification, and lengths of the survey sections. Polish lowland watercourses were surveyed. The analyzed streams represented a wide range of degradation. Several macrophyte-based metrics were evaluated, including major European systems (MTR, IBMR, TIM, MI, RI) and diversity metrics (number of species, Shannon diversity index, total cover). The reaction of the macrophyte-based metrics examined to habitat factors was compared. It was proved that some of the metrics appeared to be resistant to different sources of variability, thus confirming their usefulness for river monitoring.

Development of comprehensive river typology based on macrophytes in the mountain-lowland gradient of different Central European ecoregions

The aim of the study was to identify the vegetation pattern in the different types of watercourses basing on survey in reference conditions in a wide geographical gradient, including mountain, upland and lowland rivers. We tested relationship between composition of macrophytes to environmental variables including: altitude, slope, catchment area, geology of valley, land use, hydromorphological features, water physical and chemical measurements. Analysis based on 109 pristine river sites located throughout major types of rivers in Central Europe. Qualitative and quantitative plant surveys were carried out between 2005 and 2013. Based on TWINSPAN classification and DCA analysis, six macrophyte types were distinguished. The lowland sites were divided into the following three types: humic rivers and two types of siliceous rivers depending on the catchment area, including medium-large and small rivers. The mountain and upland rivers were divided into three geological types: siliceous, calcareous and gravel. We found that the variation of macrophyte communities was determined by several habitat factors (mainly altitude, flow type, riverbed granulometry, conductivity and alkalinity), whereas the spatial factor was rather limited; further, the plant diversity was not reflected accurately by the European ecoregion approach.

The influence of hydromorphological modifications of the littoral zone in lakes on macrophytes

The study aimed at determining the influence of hydromorphological modifications of the littoral zone in lakes on the occurrence and quantitative diversity of macrophytes. The field research was carried out at the peak of the growing season (June – September) between 2006 and 2009. Altogether, 457 transects were studied, located in 5 lakes. Studies on the hydromorphology were performed with the method of Lake Habitat Survey (LHS), and on macrophytes — with the method of transects. The studied sites were divided into 3 groups of different intensity of morphological transformations. The identified groups constituted the starting point for the analysis of influence exerted by transformations on macrophytes. The obtained results indicate that hydromorphological modifications of lakes are an important ecological factor affecting the occurrence and quantitative diversity of macrophytes. The transformations recorded in the studied reservoirs resulted mostly from recreational exploitation. They were responsible for mechanical elimination of dominant species, which led to an increased number of taxa, synanthropization and an average level of hemeroby as well as a decrease in the total vegetation cover. Helophytes were the most negatively affected group by the transformations, which reduce their contribution in the vegetation cover, whereas macroscopic filamentous algae and elodeids were positively affected.

Macrophyte and macroinvertebrate patterns in unimpacted mountain rivers of two European ecoregions

The aim of the study was to compare the patterns of development of macrophytes and macroinvertebrates in different types of reference mountain rivers. The study is based on reference river sites surveyed throughout the mountains in Poland and Slovakia in two European ecoregions (9—Central Highlands, 10—The Carpathians). A wide range of environmental variables were estimated, including water chemistry, hydromorphology, geology, and the spatial factor. Based on the Jaccard index, macrophyte and macroinvertebrate variation was confirmed between four mountain and upland river types. It was found that the biological diversification is mainly influenced by geological and associated chemical factors. In the case of macroinvertebrates, additionally, the importance of the spatial factor was revealed (difference between ecoregions). Finally, the habitat preferences of various taxa were identified. It was found that extreme mountain conditions can sometimes distort bioindicative response, as was detected in the case of macroinvertebrates in the highest mountain sites. We concluded that consideration of two groups of organisms enables more comprehensive and reliable monitoring than assessment based on a single group, especially when standard bioindicative methods can be distorted by extreme local conditions.

Influence of selected environmental factors on macroinvertebrates in mountain streams

Abstract The objectives of our survey were: to analyze the structure of macroinvetebrate communities in mountain streams in national parks and Biosphere Reserves (Poland, the Slovak Republic), to determine the environmental factors that influence the structure of macroinvertebrate communities and to assess the stream habitats including the bank and channel features, any modifications, land use and channel vegetation. Our results showed that in addition to the conductivity, the altitude, stream gradient and the values of the HQA index that reflected more natural features in the channel and river corridor were most important. The River Habitat Survey (RHS) method reflects not only the morphology but also the relationships between habitat features and the structure of macroinvertebrate communities and it provides a more holistic approach to assessing the health condition of stream ecosystems. Headwater streams support unique macroinvertebrate taxa that are found nowhere else in a catchment and may also constitute refuges for in-stream biota. Some of the least water pollution-tolerant macroinvertebrate taxa were recorded.

Habitat requirements of Elodea canadensis Michx. in Polish rivers

Abstract The main objectives of this work were to investigate the range of habitat conditions (in terms of water chemistry and hydromorphological parameters) at sites colonized by Elodea canadensis and to analyze the species composition of communities with this plant species. We analyzed physicochemical, hydromorphological and biological data from 1135 sites located in Polish rivers to identify environmental factors that determine the occurrence of Elodea canadensis. Canadian waterweed was present at 18.1% of the analyzed river sites, located mainly in the lowlands (26.2% of all lowland sites).The results show that Elodea canadensis prefers moderately mineralized water (545 ± 329 μS cm−1), rich in calcium and magnesium carbonates (174 ± 63 mg CaCO3 l−1, 84.1 ± 31.4 mg Ca2+ l−1 and 11.1 ± 6.4 mg Mg2+ l−1), with moderate concentrations of chlorides and sulfates (38.9 ± 59.1 mg Cl- l−1 and 62.3 ± 50.9 mg SO42− l−1) and in terms of nutrients, it prefers water from moderately rich to mesotrophic and eutrophic. This plant has high light requirements and grows mainly in unshaded sections of shallow rivers. The studied species avoids sections of rivers strongly transformed and those with reinforced banks and bottoms. Canadian waterweed occurs mostly in the company of vascular macrophytes associated with slow-flowing rivers with sandy bottom material, indicating mesotrophic and eutrophic water.