Climatic effect of atmospheric CO2 doubling on radial tree growth in south eastern France

The climatic effect of a doubling of atmospheric CO₂ on radial growth of trees was studied in ten populations of three species in south eastern France using an Atmospheric General Circulation Model (AGCM) predicting a 3°C increase of mean temperature and a light rise of precipitation. Results are based on empirical growth climate models, involving an Artificial Neural Network (ANN) technique. Only two of the studied populations, on the boundaries of their ecological area, are sensitive to the climatic variations. One is the larch ( Larix decidua Mill.) population located at 2300 m on elevation (near the timberline) which shows a radial growth increase. The other is the most southern French Scots pine ( Pinus sylvestris L.) population which reacts with a severe growth rate reduction.     

Nouveaux repères biostratigraphiques à terebratulidés (Brachiopodes) dans le Tithonien inférieur ouest-européen

The discovery of a new species of Terebratulid (Xestosina sera nov. sp.) in the Lower Tithonian allows to specify the biostratigraphical subdivision of the Gigas Zone. This also allows to improve the correlations, when ammonites are lacking, among the Tithonian deposits of Aquitaine, the northern Jura and the eastern border of the Paris Basin. The critical revision of the Xestosina genus gives a nomenclatural setting argued to the index-species of biozones. It constitutes a brachiopods based parallel scale for the Kimmeridgian and Tithonian Stages.     

L'indice thermique,un essai de méthodepour comparer et utiliser climatologiquement les gisements quaternaires. Application aux oiseaux du Pléistocène Français

The birds found in the Middle and Upper Pleistocene sites of France can be classified in four categories according to the thermic requirements of present forms. A «guide-number growing from 1 to 4 and corresponding to an increasing temperature has been ascribed to each category. The «Thermic index is calculated from this guide-number and takes into account the relative frequency of species.The different values obtained for the main fossilavifaunas allow to find climatic fluctuations that, in the whole, confirm the facts already known, which therefore allows to test the method.     

The life expectancy of phlebotomine sandflies: first field estimates from southern France

Abstract. 1. A field study of Phlebotomus ariasi Tonnoir, the vector of Leishmania infantum Nicolle in southern France, addressed the following questions: Is it possible to estimate reliably the life expectancy of this sandfly; can spatial or temporal variation in the life expectancy be detected, and is such variation significant for disease transmission? 2. Life expectancy was estimated by examining follicular relics in the ovaries of more than ten thousand females caught in light traps at seven sites in the Cévennes and the Garrigues, throughout their active period in 1985 and 1986. Whilst the distinction between nulliparous and parous flies was easily made, assessments of the number of times a parous fly had laid eggs were unreliable. Best estimates of life expectancy were therefore calculated from the parous rate. 3. Large samples collected from one site in the Cevennes in both years gave very similar estimates of life expectancy. 4. There was also no significant difference between estimates obtained from the Cévennes and the Garrigues, despite their distinct vegetation and climates. Therefore, large regional differences in sandfly population size and the prevalence of canine leishmaniasis cannot be explained by a difference in adult survival rate. 5. With no systematic annual or regional variation, a useful mean life expectancy can be calculated from the data collected at all sites in both years. It is 1.54 (SE 0.04) ovarian cycles. However, this estimate is sensitive to the assumption that survival rate is a discrete rather than a continuous variable. 6. Local variation in the parous rate may be associated with the proximity of traps to P.ariasi emergence sites.     

A new look at the Late Jurassic Canjuers conservation Lagerstätte (Tithonian,Var, France)

The Canjuers conservation Lagerstätte represents a Late Jurassic lagoonal environment. The sedimentology and stratigraphy of the locality show three different depositional sequences. Fossils are mainly found in the basalmost layers that correspond to the first phase of deposition in the lithographic limestones sensu stricto. The fossil biodiversity is rich. So far, more than 1000 specimens including 38 invertebrate and 18 vertebrate taxa have been recovered from the limestones. The depositional information suggests that most invertebrates and vertebrates were not autochthonous to the lagoon, but swept in during storm events from the open sea or nearby emerged reef environments.     

The oldest Cenozoic passandrid (Coleoptera: Cucujoidea: Passandridae) from the Paleocene of Menat (France)

The new oldest representative of the subfamily Passandrinae (Passandridae) was found in materials from Menat (Puy-de-Dôme, France). It was preliminarily assigned to the genus Passandra Dalman in Schönherr, 1817, although the new species (?) Passandra plenaria sp. n., in contrast to other congeners, demonstrates an exposed labrum and an absence of preapical groove or impression on the hypopygidum. Some notes on fossil records and classification of the family Passandridae are made. The distinctiveness of the families Passandridae and Laemophloeidae in light of the new data on fossils is considered, and the attribution of Mesopassandra Jin, Ślipiński, Zhou and Pang, 2019 (type genus of Mesopassandrinae) to the family Passandridae is regarded as problematic.     

Honeydew sugars in wild-caught Phlebotomus ariasi detected by high performance liquid chromatography (HPLC) and gas chromatography (GC)

Phlebotomus ariasi Tonnoir sandflies were caught in light traps hung in oak trees and in a house in the Cévennes focus of leishmaniasis in the South of France. The flies were cryopreserved either immediately on removal from the traps, or after starvation for 6-7 days, or after 6-7 days starvation followed by exposure to oak infested with the aphid genera Lachnus or Thelaxes. After transportation to the laboratory, the sandflies were thawed and aqueous extracts of the crushed flies were analysed for their carbohydrate content using high performance liquid chromatography (HPLC) and gas chromatography (GC). Starved female sandflies lacked significant amounts of any saccharides. Four types of sugar, melezitose and its hydrolysis products turanose, glucose and fructose, were observed in flies which had been starved previously and then placed with Lachnus infested oak. The results also indicate the presence of hydrolysis products of melezitose: (a) in flies previously starved and placed with Thelaxes infested oak, (b) in P.ariasi cryopreserved direct from the light traps hung in oak trees infested with Lachnus and Thelaxes, and (c) flies caught in a house. Unidentifiably small quantities of a trisaccharide were also detected in the latter groups of flies. In previous tests, sugars were detected in P.ariasi after their exposure to aphid-infested oak (Quercus ilex L.), but not when P.ariasi females were exposed to washed oak leaves without aphids. The results indicate that P.ariasi feed on melezitose and/or turanose, the main local source of which is aphid honeydew. A better understanding of sugar meal sources of sandflies using HPLC and GC techniques will assist in our understanding of sandfly/Leishmania relationships, parasite transmission and epidemiology.     

Bioturbational redistribution of Danian calcareous nannofossils in the uppermost Maastrichtian across the K-Pg boundary at Bidart, SW France

In this paper we present the effects of different tracemakers on the redistribution of calcareous nannofossils throughout the K-Pg boundary at the Bidart section (SW France), along with their consequences for our knowledge of the K-Pg boundary event. Danian calcareous nannofossil assemblages are present in Maastrichtian samples due to infiltration into dark trace fossil infillings proceeding from the earliest Paleogene. This is evidenced by the appearance of abundant paleogene calcareous nannofossils just below the K-Pg boundary, showing the relevance of the trace fossil infillings in the context of the K-Pg boundary event.