Abstract:We analysed the influence of environmental stress (mainly deforestation of catchment due to windstorm) on taxonomic structure as well as composition of functional groups (FG) based on zonation preferences and feeding types of caddisfly species in 11 streams (12 sites) with various environmental conditions situated in the High Tatra Mts, Slovakia. Using Spearman correlation, we confirmed an expected positive association between taxonomic and functional groups richness (Ri), diversity (Shannon -Wiener Index) (Di) and equitability (Eq), but not with habitat diversity (HQA indices). By testing measured physiographical, physico-chemical and hydromorphological factors using CCA analysis we found that stream order and temperature best explained the functional and taxonomic structure of caddisfly assemblages. The occurrence of Rhyacophila glareosa decreased with increasing daily mean water temperature positively correlated with deforestation, whereas R. tristis (dominating at sites most affected by erosion) showed the opposite pattern. Composition of functional groups based on zonation preferences and feeding types distinguished well near natural sites from impacted ones, dominated by crenal/rhithral predators, and explained more of the overall variance of the species-environment relationships than taxonomic composition of caddisfly assemblages.
In this study we describe how the river morphology of seven High Tatras streams has been influenced in different ways by a severe windstorm that occurred in November 2004. A control site situated in an undisturbed area is compared with six sites in windstorm damaged areas. In 2009-2010 River Habitat Survey (RHS) was used to assess the character of 500 m lengths of stream and to derive associated morphological indices (HQA, HMS sensu Raven 1998, RHS indices sensu Vaughan 2010). Large amounts of large woody debris in the channel influenced the streams despite most of it having been removed after the windstorm. Streams situated in deforested valley slopes were probably more affected by erosion; they had higher amounts of transported inorganic matter and also depositional bar features. Some changes in land-use had occurred with streams situated on the south-east side of the High Tatras having a more uniform banktop vegetation structure than the other streams. Distinct secondary succession of bank top vegetation was observed along windstorm influenced streams. The highest percentage of shrubs occurred where impacted streams remained untouched. Morphologically, the streams most affected by windstorm are those situated in deforested steep valley slopes that are affected by erosion and siltation.
Hydrobiological research of high mountain streams in the High Tatras was carried out in [2009][2010]. We evaluated the influence of windstorm on caddisfly assemblages. To assess the influence of windstorm we focused on river morphology using the RHS method and evaluation of TAM, TOM and BOM (CPOM, FPOM, UFPOM) amount in seven streams. Site 1 was a control and the other six were disturbed by the windstorm in different ways. The most remarkable differences compared to the control site was in feeding structure at sites most affected by erosion. In these streams there was a noticeable dominance of predators from the family Rhyacophilidae (mainly Rhyacophila tristis; sites 3, 4, 5, 6) and a remarkable decrease of passive filter feeders (site 4, 5). Using Spearman coefficient we confirmed a positive correlation between the proportion of predators and amount of TAM caused by erosion of steep deforested slopes of windstorm affected sites. In contrast, we did not observe such an increase in the proportion of predators at site 7, which was affected by both windstorm and subsequently by fire. This might be explained by the shallow vee valley with no observed erosion, where this site is situated. We also found a negative correlation between predators and evenness, indicating unstable community structure clearing succesion in the streams disturbed by erosion, and a negative correlation between passive filter feeders and UFPOM. We found out that overhanging tree boughs and LWD had an influence on species composition. RHS was a useful tool in characterising the influence of hydromorphology on caddisfly assemblages.
Attempting to help reduce the costs of bioassessment of aquatic habitats, the aim of this study was to estimate how particular substrate types influence the ecological quality evaluation based on a multihabitat scheme proposed by the AQEM/STAR consortium. Samples of macroinvertebrates were taken from the Stupavský potok brook, a small, 4
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.