Impacto de la siega y el pastoreo de las ovejas en arañas y carábidos activos del suelo de algunos marjales salinos intermareales (oeste de Francia)

The aims of this study were to characterize spider (Araneae) and ground beetle (Coleoptera, Carabidae) communities in managed (cutting and sheep grazing) and non–managed salt marshes and to assess the efficiency of management regimes in these particular ecosystems. The two groups were studied during 2002 in salt marshes of the Mont Saint–Michel Bay (NW France) using pitfall traps. By opening soil and vegetation structures cutting and grazing enhanced the abundances of some halophilic species of spiders and ground beetles. Nevertheless, grazing appeared to be too intensive as spider species richness decreased. We discuss the implications of management practices in terms of nature conservation and their application in the particular area of intertidal salt marshes. Key words: Management, Conservation value, Halophilic species, Arthropods.El objetivo de este estudio es caracterizar las comunidades de arañas (Araneae) y escarabajos del suelo o cárabos (Coleoptera, Carabidae) en marjales salinos gestionados (siega y pastoreo) y no gestionados y, por lo tanto, valorar la eficacia de lo regímenes de gestión en estos ecosistemas particulares. Ambos grupos fueron estudiados durante el año 2002 en distintos marjales salinos de la bahía de Mont Saint–Michel (NO de Francia) mediante trampas de intercepción. La siega y el pastoreo, al abrir el suelo y las estructuras vegetales, hacían aumentar la abundancia de algunas especies halófilas de arañas y cárabos. No obstante, parece ser que el pastoreo era demasiado intensivo ya que la riqueza de especies de arañas disminuía. Se discuten las implicaciones de las prácticas de gestión en términos de la conservación de la naturaleza y también su aplicación en zonas tan especiales como son los marjales salinos intermareales. Palabras clave: Gestión, Valor conservativo, Especies halófilas, Artrópodos

Classification of underwater photogrammetry data for temperate benthic rocky reef mapping

International audienceThe fine characterization of the substrate is a baseline to thoroughly investigate the relations between organisms and their biotopes. Cutting edge spatial technologies now provide access to accurate information on biotopes and biocenoses both in terrestrial and in marine environments. Photogrammetry is one of them and has recently been applied in submarine environments especially in shallow clear water. In this study, we investigated the potential of photogrammetry to characterise benthic habitats in turbid environments. Although more challenging, turbid environments are more frequent in temperate marine coastal areas. We selected two rocky sites in the bay of Saint-Malo (Brittany, France), differentiated by their level of turbidity, one being a marine site exposed to natural tides (Buharats), while the other (Bizeux) is subjected to both natural tides and artificial currents created by the functioning of a hydroelectric dam. The different substrates observed were classified into eight classes at a centimetre resolution using photogrammetry-based spatial and multispectral predictors. The spatial benthic terrain predictors were derived from a digital surface model (DSM) at various spatial scales, and the multispectral predictors were retrieved from the red-green-blue (RGB, natural colours) orthomosaic imagery. An overall classification was computed for Buharats and Bizeux, with accuracies of 84.76% and 79.54% respectively, revealing a good quality of the substrate classification. The combination of RGB, DSM, and several spatial benthic terrain variables, with a pixel resolution of 5 and 10 mm, and a kernel size of 30, 60 and 90 pixels leads to the best benthic substrate classification (highest overall accuracy). At the class scale, producer's (PA) and user's (UA) accuracy showed that big boulders and field material were correctly distinguished. Small boulders and cobbles, having similar sizes, showed the lowest classification performances. This classification methodology provides new perspectives for mesoscale (100 m2 to 1 km2) semi-automatic mapping of the fine resolution (1 cm) relationship between benthic organisms and their substrate

Spontaneous recovery of functional diversity and rarity of ground-living spiders shed light on the conservation importance of recent woodlands

International audienceSecondary (or recent) woodlands, whose development is favoured by massive farmland abandonment, are increasingly seen as promising habitats that limit losses of biodiversity and ecosystem processes. The importance of temporal forest continuity (i.e. the duration of an uninterrupted forest state) for conservation of the forest fauna has been demonstrated for several taxa, but its influence on functional diversity and conservation importance of communities remains unclear. We studied how temporal continuity can shape taxonomic and functional composition and structure of forest-ground spider communities at a regional scale. According to broad-scale ecological site characteristics, species composition and—to a lesser extent—trait distribution substantially diverged between ancient and recent forest sites. Yet, we found hardly any significant differences in functional β-diversity, community structure, or conservation importance between the two forest categories. The only difference was for functional originality, which quantifies the average functional uniqueness of species within an assemblage spiders’ communities of the ancient forests was more functionally original than those of the recent woodlands. Thus, in a conservation perspective, our study provides evidence that each forest harbours original species combinations, suggesting that each of them is irreplaceable, especially for ancient forests, which are functionally more original; however, recent woodlands have a high potential to spontaneously recover typical forest fauna communities with very similar structural and functional profiles to those of ancient forests

Wartime Allowances to the Families of Servicemen in Germany during the World War I (1)

はじめに　Ⅰ　応召兵士家族支援の制度的枠組み （1）1888／1914年〈兵士家族支援法〉（a)1888年〈兵士家族支援法〉／1914年〈改正法〉の規定（b）〈兵士家族支援法〉の実施 （2）1916年1月21日〈連邦参議院布告〉（a)1916年1月21日〈連邦参議院布告〉の規定（b)〈連邦参議院布告〉の解釈と実

Are phenological patterns of ballooning spiders linked to habitat characteristics?

We describe here the phenological patterns of the 25 most common ballooning species of spiders caught by a 12.2 m suction trap during an eleven year survey in Switzerland. We aimed at identifying and quantifying the number, position, spread, and relative weight of activity periods for the whole community. Further, we explored the possible link between phenological patterns and habitat use. For this purpose, we used bump-hunting approaches and fitted mixtures of normal distributions to the abundance data. The phenologies can be grouped in four categories, from uni- to quadrimodal. The specific peaks in the timing of ballooning were found between February and November, with most ballooning activity occurring in summer and autumn. For some taxa, it was possible to analyze the data for young instars and adults. For the majority of taxa, the adults’ peak appeared between the early and late peaks of immature individuals. Species inhabiting the ground level of open areas, often disturbed by agricultural practices, were clearly dominant in the multimodal categories; spiders living in more closed and stable habitats, such as tree-shrub and herb layers, typically had a single peak of adult dispersal. This discrepancy in phenology may simply reflect different numbers of generations, but may also result from an adaptation to maximize the persistence of populations in unstable habitats.Peer reviewe

Diversidade e estimativas de riqueza de aranhas em quatro fitofisionomias na Serra do Cachimbo, Pará, Brasil

Um inventário da fauna de aranhas foi realizado na Serra do Cachimbo, no Campo de Provas Brigadeiro Velloso, município de Novo Progresso, Pará. As coletas ocorreram em duas expedições, uma na estação seca (agosto e setembro de 2003) e outra na chuvosa (março e abril de 2004). Cada expedição contou com a participação de três coletores. O esforço de amostragem foi de 240 amostras, sendo 96 através de guarda-chuva entomológico e rede de varredura, 96 através de coleta manual noturna e 48 por triagem manual e extratores de Winkler. Foi comparada a diversidade de aranhas de quatro tipos de vegetação, Floresta Ombrófila Aberta, mata de galeria, áreas de Cerrado (Savana Arbórea) e de Campina. As coletas resultaram em um total de 4.990 indivíduos, dos quais 2.750 adultos. Foram identificadas 427 morfoespécies em 37 famílias, sendo as mais abundantes Theridiidae, Salticidae e Araneidae e as mais ricas em espécies Araneidae, Salticidae e Theridiidae. As espécies representadas por apenas um indivíduo somaram 40% do total e apenas duas ultrapassaram cem indivíduos. A curva de riqueza específica estimada (ACE) atingiu 614 espécies. A maior diversidade alfa (índice de Shannon-Wiener) foi encontrada em Floresta Ombrófila, seguida pela mata de galeria, Campina e Cerrado. Tais diferenças entre as vegetações podem ser explicadas devido a variações na complexidade da vegetação e na disponibilidade de microhábitats em cada fitofisionomia