Dalechampii oak (Quercus dalechampii Ten.), an important host plant for folivorous lepidoptera larvae

El roble de dalechampii (Quercus dalechampii Ten.), una importante planta hospedadora de las larvas de lepidópteros filófagos Llevamos a cabo un análisis estructurado de las taxocenosis de larvas de lepidópteros que viven en las copas del roble de dalechampii (Quercus dalechampii Ten.) en nueve parcelas del estudio en los Pequeños Cárpatos (Europa central). Se analizaron las diferencias entre las taxocenosis de lepidópteros de cada roble. Se hallaron 96 especies y 2.140 individuos. La abundancia de especies alcanzó su valor más elevado en mayo, mientras que el número y la diversidad de especies fueron máximos desde abril hasta mayo y desde abril hasta junio, respectivamente. La abundancia mostró dos máximos notables en las larvas que se alimentan durante la brotación y las que se alimentan al final del verano. La taxocenosis de los lepidópteros en la parcela del estudio Horný háj (un bosque aislado con una elevada densidad de hormigas) difirió significativamente de las demás taxocenosis según el índice de Sörensen para la similitud de las especies, la diversidad de las especies, el análisis de la similitud sobre la base de las pruebas de permutación y las pruebas de pares (ANOSIM), la variabilidad estacional de la composición de especies y el escalamiento multidimensional no métrico (NMDS por sus siglas en inglés)

Modèles ecologiques pour l'extrapolation des effets écotoxicologiques enregistrés lors de biotests in situ cheZ Gammarus

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCAInternational audienceEvaluating the effects of chemical contamination on populations and ecological communities still constitutes a challenging necessity in environmental management. However the toxic effects of contaminants are commonly measured by means of organism-level responses. Linking such effects measures with ecological models is a promising way to apprehend population-level impacts. In this way, population models are currently increasingly used in predictive risk assessment procedures, but their use in environmental diagnostic framework remains limited due to their lack of ecological realism. The present study with the crustacean amphipod Gammarus fossarum, a sentinel species in freshwater monitoring, combines a dual field and laboratory experimental approach with a population modelling framework. In this way, we developed an ecologically-relevant periodic matrix population model for Gammarus. This model allowed us to capture the population dynamics in the field, and to understand the particular pattern of demographic sensitivities induced by Gammarus life-history phenology. The model we developed provided a robust population-level assessment of in situ-based effects measures recorded during a biomonitoring program on a French watershed impacted by past mining activities. Thus, our study illustrates the potential of population modelling when seeking to decipher the role of environmental toxic contamination in ecological perturbations

Occurrence of protected species ( Gomphus flavipes , Odonata and Palingenia longicauda , Ephemeroptera) in the Danube River and its deltas (Romania, Slovakia)

Till now, altogether 50 species of dragonflies have been found in the Danube and its arms in Slovakia. One of the most important indicator species is Gomphus (Stylurus) flavipes, listed as strictly protected by Appendix II of the Bern Convention. Large population of Gomphus flavipes was found in the Malý Dunaj (Small Danube), in the area called Danube’s “Inland Delta”, in 2000–2001. Watching of dragonflies in the Danube Delta (Romania) demonstrated another large population in 2007–2008. In contrast with these observations are our results, from long–term monitoring of dragonflies in the Danube, in the area influenced by the Gabčíkovo power plant (operational since 1992). Changes in hydromorphology in this section started in 19 th century and at present dam represents a significant impact on the functioning of the Danube ecosystem. During 20 years monitoring we found only one larva of Gomphus flavipes in the Danube at the site downstream of the dam. Another critically endangered species, mayfly Palingenia longicauda was found in the Danube Delta in 2009. We observed emergence of giant mayfly in the Danube ́s arm in Romania. Palingenia longicauda disappeared totally in the 1930s from many European rivers. At present it occurs in Tisza and Rába rivers (Hungary) and has been reintroduced in Lippe and Odra rivers (Germany). New findings of large populations of Palingenia longicauda in the Romanian Delta has been unknown till now. Findings of large population of Gomphus flavipes in deltas confirm that river deltas are of high importance for aquatic biodiversity conservat

Dalechampii oak (Quercus dalechampii Ten.), an important host plant for folivorous lepidoptera larvae

We conducted a structured analysis of lepidoptera larvae taxocenoses living in leaf bearing crowns of Dalechampii oak (Quercus dalechampii Ten.) in nine study plots in the Malé Karpaty Mountains (Central Europe). The differences between lepidoptera taxocenoses in individual oak stands were analyzed. A total of 96 species and 2,140 individuals were found. Species abundance peaked in May, while number of species and species diversity reached the highest values from April to May and from April to June, respectively. Abundance showed two notable peaks in flush feeders and in late summer feeders. Lepidoptera taxocenosis in the study plot Horný háj (isolated forest, high density of ants) differed significantly from all other taxocenoses according to Sörensen’s index of species similarity, species diversity, analysis of similarity on the basis of permutation and pairwise tests (ANOSIM), seasonal variability of species composition, and NMDS ordination

Community structure, life histories and secondary production of stoneflies in two small mountain streams with different degree of forest cover

Our study examines community structure and nymphal biology (life cycles and secondary production) of stoneflies in two adjacent mountain streams with different degree of forest cover in the Prosiečanka River Basin (Chočské Vrchy Mts., West Carpathians). One of the streams has non-forested catchment, converted to meadows and pastures, while the other one has catchment with 60% covered by spruce forest. Differences in forest cover and in thermal regime of the streams were reflected by the difference of stonefly communities at their structural and functional level. Species Nemoura cinerea and Leuctra aurita created stonefly assemblage in non-forested stream, whereas Nemoura cinerea also occurred in naturally forested stream together with species Leuctra armata, Leuctra nigra, Leuctra prima, Siphonoperla neglecta and Arcynopteryx dichroa. All examined species had maximally annual life cycle and in eudominant species Nemoura cinerea one month shift was found in nymphal hatching and adult emergence between streams. Total secondary production of stoneflies in undisturbed stream (126.46 mg DW m-2 y-1) was more than two times higher than the production in non-forested stream (47.39 mg DW m-2 y-1). </p