Effects of flow events and nutrient addition on stream periphyton and macroinvertebrates: an experimental study using flumes

We used flume experiments to study the effects of a temporary increase in stream flow on macroinvertebrates, leaf litter breakdown and soft-bodied benthic algae; both as a single stressor and eventually in combination with an increase in nutrient supply. In order to understand how well the flumes reflected the nearby stream ecosystem, we compared species composition of macroinvertebrates and benthic algae between the flumes and the nearby stream from which the flumes were supplied with water. As single stressors, nutrient addition and an increased flow velocity from 1.3 to 2.8 cm s����� 1 lead to an increase in the biomass of benthic algae, likely reflecting an improved transfer of nutrients into algal patches. However, the combined effect of flow and nutrient addition was smaller than the sum of both individual effects, likely because an increased biomass also was more susceptible to scouring. We found differences in macroinvertebrate and benthic algal taxon identity and abundance between stream and flumes. Since biodiversity is assumed to stabilize ecological functioning in response to disturbances and variation, we conclude that care should be taken in applying results from small scale experiments to stream ecosystems.publishedVersio

A description of Cernosvitoviella tridentina, a new species of Enchytraeidae (Oligochaeta) from the Italian Alps.

A new species of Enchytraeidae, Cernosvitoviella tridentina sp.n., is described from alpine streams (Stelvio National Park, Trentino). C. tridentina sp.n. belongs to a group of species with spermathecae confined to the V segment; it particularly resembles Cernosvitoviella carpatica (Cernosvitov), C. minor Dozsa-Farkas and C. celere Nurminen, but differs from these species by some important anatomical features: the presence of small seminal vesicles, longer ectal ducts of the spermathecae and (from two first species) by deep incision of the posterior margin of the brain

A new species of

A new species, Fridericia dissimilis n. sp., found during a study of the aquatic oligochaete fauna in the region of [math]nie[math]nik Massive (Sudety Mts, south-western Poland) is described. The species belongs to the Fridericia group of species characterised by asymmetrical spermathecae with a single diverticulum, but it is easily distinguished from other species by, the enormous size of the gland at the ectal orifice of the spermatheca and the shape of ampulla, andby the shape of the brain and seminal vesicles

Natural and anthropogenic factors that participate in the forming of the spring and benthic invertebrates in the karst area of Cracow–Częstochowa Upland (Poland)

The authors have carried out their investigations at the karst carbonate massif of the Cracow–Częstochowa Upland (CCU) since the 1990s of the XX century. The Upper Jurassic aquifer, which is a Major Ground Water Basin (MGWB No 326), was delimited in this area. It is closely connected with surface waters including living biocenoses and other dependent from the state of water. At the area of the CCU exist several hundred springs. At the drainage areas of springs authors conducted interdisciplinary investigations, including hydrogeological, geochemical, geological studies performed in spring drainage areas. The communities of benthic invertebrates were determined as the biomarkers of the environmental state. In natural springs remarkable groups of species such as oligostenothermic, crenophilic or crenobiontic prevailed whereas in springs under anthropopression mainly eurybiontic species could be stated. Stygobiontic species were also found in a few springs. The study, done together with the recognition of regional land management and pollution sources, allow to estimate the influence of natural and anthropogenic factors on water environment and its biotic elements within the karstic area of the CCU

Invertebrate communities in permanent and temporary high mountain lakes (Tatra Mts)

Water chemistry and macroinvertebrates of four high mountain lakes (alt. 1657-1784 m) were investigated. The lakes are ultraoligotrophic with naturally slightly acidic water. In three lakes these water level changed substantially during the year while in one it remained constant. Moreover, trophic status was higher in one than in the other three. Oligochaeta and Chironomidae dominated the invertebrate fauna of all lakes. Benthic faunal composition depended mainly on ecological factors such as substrate, trophic status, and hydroperiod. It appears that anthropogenic acidification has so far not affected faunal composition