Dinâmica e distribuição vertical de uma população de Hrabeiella periglandulata (Annelida) no Sul da Morávia, República Tcheca

The objective of this work was to evaluate the density, dynamics and vertical distribution of a Hrabeiella periglandulata population in a forest soil at Brno, Czech Republic. From December 2003 to November 2004, two plots covered by mixed stands and two covered by coniferous stands were sampled monthly. Six soil cores per plot were taken down to 15 cm and subdivided into layers, which were subjected to wet funnel extraction. Missing in one of the coniferous stands H. periglandulata was abundant in the mixed stand with the highest soil pH. In this stand, monthly sampling continued until November 2005, with three additional samplings up to January 2007. Mean annual density was 2,672±1,534 individuals m-2. Population dynamics differed from those reported from Germany. Highest densities were reached in early summer, lowest between August and December. Due to aggregated horizontal distribution, differences between monthly values were often nonsignificant. No significant correlation with climatic data was found. Nevertheless, the observed dynamics corresponded to the climatic conditions, showing particularly the negative effect of drought. The population was evenly distributed in the sampled soil profile, only avoiding the organic layer. Except for a locality in Poland, this is the easternmost record of the species.O objetivo deste trabalho foi avaliar a densidade, a dinâmica e a distribuição vertical de uma população de Hrabeiella periglandulata em uma floresta de Brno, República Tcheca. De dezembro de 2003 a novembro de 2004, amostras de solo foram coletadas mensalmente, em duas áreas de floresta mista e duas áreas de floresta de coníferas. Em cada área, seis amostras de solo foram retiradas até a profundidade de 15 cm, subdivididas em camadas e colocadas para extração úmida em funil. Não encontrada em uma das áreas de floresta de coníferas, H. periglandulata foi abundante na área de floresta mista com pH do solo mais alto, onde a amostragem mensal continuou até novembro de 2005, com três amostragens adicionais até janeiro de 2007. A densidade média anual foi de 2.672±1.534 indivíduos por m2. A dinâmica populacional diferiu da encontrada na Alemanha. As maiores densidades foram encontradas no início do verão, e as menores entre agosto e dezembro. Em razão da distribuição horizontal agregada, diferenças entre os valores mensais foram, frequentemente, não significativas. Nenhuma correlação significativa com dados climáticos foi encontrada. No entanto, as dinâmicas observadas corresponderam às condições climáticas, particularmente, ao efeito negativo da seca. A população foi homogeneamente distribuída no perfil de solo amostrado, e evitou, somente, a camada orgânica. Com exceção de uma localidade na Polônia, este é o registro mais a leste sobre esta espécie

Sur l'occurrence massive de deux espèces rares de coléoptères saproxyliques Cucujus cinnaberinus (Cucujidae) et Dircaea australis (Melandryidae) dans les forêts alluviales du sud de la Moravie

From 2003 to 2005 saproxylic beetles were studied by means of flight interception traps in three old growth floodplain forest stands, dominated by pedunculate oak and narrow-leaved ash, near the confluence of the Morava and Dyje rivers in South Moravia (Czech Republic). At each site 10 traps were operated for two seasons from the last third of April or beginning of May till end of September or middle of October. Analysis of the catch is underway; the present results are based on two seasons at the Dlúhý hrúd site and the Ranšpurk National Nature Reserve, but only on one season in case of Cahnov-Soutok National Nature Reserve. The trapping yielded noteworthy high numbers of two rare and threatened saproxylic species, Cucujus cinnaberinus and Dircea australis, 10 and 63 specimens, respectively. First records of D. australis from this area, and thus from the Czech Republic, are from the 1990s. C. cinnaberinus was found exclusively in April and May, whereas D. australis was trapped from the second half of May till the first half of August, predominantly from July onwardsDe 2003 à 2005 les coléoptères saproxyliques ont été étudiés à l'aide de pièges à interception dans trois vieilles formations de forêt pluviale, à dominance de chêne pédonculé et de frêne à feuilles étroites, près de la confluence de la Morava et de la Dyje dans le sud de la Moravie (République Tchèque). Sur chaque site 10 pièges ont été placés durant deux saisons du dernier tiers d'avril ou du début mai jusqu'à la fin septembre ou la mi-octobre. L'analyse des captures est en cours. Les présents résultats s'appuient sur deux saisons à Dlùhy hrùd et dans la réserve naturelle nationale de Ranspurk mais sur une seule saison dans la réserve naturelle nationale de Cahnov-Soutok. Le piégeage a donné des nombres remarquablement élevés, respectivement 10 et 63 spécimens, de deux espèces saproxyliques rares et menacées, Cucujus cinnaberinus et Dircea australis. Les premières données sur D. australis dans cette région et donc pour la République Tchèque datent des années 1990. C. cinnaberinus a été capturé de la seconde moitié de mai à la première moitié d'août, essentiellement à partir de juillet

The wave towards a new steady state: effects of earthworm invasion on soil microbial functions

Earthworms are ecosystem engineers that cause a long cascade of ecological effects when they invade previously earthworm-free forests. However, the consequences of earthworm invasion for soil microbial functions are poorly understood. Here, we used two well-studied invasion fronts of European earthworms in northern North American hardwood forests previously devoid of earthworms in order to investigate three stages of earthworm invasion: uninvaded, the front of the leading edge of earthworm invasion and locations invaded at least 10 years previously. Soil microbial biomass, respiration and metabolic quotient were measured. Earthworms had marked effects on soil microbial biomass (−42%) and respiration (−32%). At both sites, impacts were most pronounced at the leading edge of the invasion front, significantly decreasing soil microbial C use efficiency. This was most likely due to the disturbance of the soil microbial community caused by water stress. Based on these results, we hypothesize that effects of earthworm invasion on native soil ecosystem functioning are most pronounced at the peak of the invasion wave. After experiencing this wave, ecosystems possibly enter a new steady state with altered biotic compositions and functions

Entwicklung von Methoden und einfachen Geraeten zur Bestimmung der Oberflaechentragfaehigkeit von Waldboeden zum Zwecke der Minimierung von Boden- und Baumwurzelschaeden, die durch den Einsatz von Holzrueckefahrzeugen und Holzerntemaschinen entstehen koennen

SIGLEAvailable from TIB Hannover: FR 5343 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Cultural treatments and woody debris: the study case of beech forests in Casentino (Italy)

This paper shows the first results about quantity and quality of dead wood on the ground in beech forests of Foreste Casentinesi, Monte Falterona and Campigna National Park. The presence of dead wood depends on several factors such as forest productivity, natural disturbances and human activities. Data from some mature managed beech stands have been collected and compared with those from unmanaged beech forest (Sasso Fratino full-protected Reserve). Results do not show significant differences between managed and unmanaged forests. The dead wood varies between 5 and 8 Mg ha-1 (in terms of total dry weight) mostly composed by fine woody debris