Caddisfly assemblages of high mountain streams (The High Tatra Mts, Slovakia) influenced by a major windstorm event

Abstract

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.

Caddisflies (Trichoptera) as good indicators of environmental stress in mountain lotic ecosystems

“…HQA total: overall habitat diversity = sum of scores of habitat diversity of channel (HQA channel), banks (HQA banks), landuse within 50 m from both banktops and within 500 m of the stream reach (HQA luse 500) and scores of features of special interest (HQA spec int), such as waterfalls according to Raven et al (1998). Values marked with asterisk adopted according to Kalaninová et al (2013 cal parameter stream order (P = 0.002; F = 6) and the physical parameter temperature -Deg. Days (VI-IX) C • (P = 0.006; F = 3.47) (Fig.…”

Influence of selected environmental factors on macroinvertebrates in mountain streams

“…For example, the RHS was a useful tool in assessing the influence of the hydromorphology on caddisfly assemblages in high mountain streams [5]. The characteristic responses of macroinvertebrate communities to anthropogenic disturbances in a stream's corridor and the adjacent area are a reduction in the number of macroinvertebrate taxa and diversity, alterations of the community composition and feeding guilds.…”

River morphology of mountain streams influenced by an extreme windstorm in the High Tatra Mountains (northern Slovakia)

“…There is a rapid succession in riparian vegetation and land-use of affected streams. We suppose that change in landuse is only temporary and more negative impacts on the aquatic biota result from erosion in steep deforested slopes in asymmetrical valleys, whereas streams situated in shallow vee valley are not so strong affected (Kalaninová et al 2013).…”