Ryszard Staniszewski

Occurrence and variability of River Habitat Survey features across Europe and the consequences for data collection and evaluation

River Habitat Survey (RHS) data collected for the EU-funded STAR project was used to identify hydromorphological characteristic features of rivers in four European regions namely: lowlands; mountain; the Alps; and the Mediterranean. Using RHS attributes, Habitat Quality Assessment (HQA) – a measure of natural habitat diversity, and Habitat Modification Score (HMS) – a measure of anthropogenic modification, we identified considerable differences in frequency, diversity and evenness of features between the regions. A relatively small subset of features clearly distinguish the hydromorphological characters of lowland, Alpine and southern European rivers. It was more difficult to distinguish mountain rivers from Alpine rivers. The highest statistical differences are observed between Lowland and Mountain region. Within the four regions studied the RHS attributes that most strongly influence the HQA and HMS indices were identified. We conclude that specific effort should be made to ensure these are recorded properly as part of the quality control of RHS data.

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.

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.

Variability of lowland river habitat features and their impact on macrophyte diversity

River habitat i s atfected by a range o f physica1 an d chemica1 components. Changes in river habitat strong1y intluence p1ant deve1opment, distribution and diversity of vegetation (WESTLA.KE 1975, HASLAM 1987). Accurate assessment o f river habitat change is becoming increasing1y important to understand the consequences for river biodiversity, and he1p environmental planning and proper management action (RAYEN et al. 2002). The purpose ofthis study was to identify the most variab1e elements ofthe lowland river habitat and to assess their impact on macrophyte diversity.