Ce que la reconstruction comparative peut apporter à la morphologie constructionnelle. Une cavalcade étymologique

This paper reconsiders the etymology of the lexical units Cat. cavalcar, encavalcar, descavalcar and their cognates, e.g. Span. cabalgar, Port. encavalgar, or It. discavalcare. An etymological cavalcade in the framework of the Dictionnaire Étymologique Roman (DÉRom) yields three Proto-Romance etyma: */ka'βall‑ɪk‑a‑/, */ɪn‑ka'βall‑ɪk‑a‑/, and */dɪs‑ka'βall‑ɪk‑a‑/. These etyma, out of which only the first one presents a correlate in written Latin, owe their existence to the application of comparative reconstruction to the Romance lexicon, the last ones respresenting derivatives from */ka'βall‑ɪk‑a‑/ with the prefixes */ɪn‑/ and */dɪs‑/

Species variables or environmental variables as indicators of forest biodiversity: a case study using saproxylic beetles in Maritime pine plantations

To assess the sustainability of plantation forest management we compare two types of biodiversity indicators. We used the species richness of saproxylic beetles as a case study to test the “species” and “environmental” indicator approaches. We compared single species abundance or occurrence and deadwood volume or diversity as predictor variables. • Beetles were sampled with flight interception traps in 40 Maritime pine plantation stands. The volume and diversity of deadwood was estimated with line intersect and plot sampling in the same stands. Predictive models of species richness were built with simple linear or Partial Least Square regressions. • Deadwood variables appeared to be good predictors of saproxylic beetle richness at the stand-scale with at least 75% of variance explained. Deadwood diversity variables consistently provided better predictive models than volume variables. The best environmental indicator was the diversity of deadwood elements larger than 15 cm in diameter. • By contrast, the use of “species variables” appeared to be less relevant. To reach the quality of prediction obtained with “environmental variables”, the abundance or occurrence of 6 to 7 species – some of which are difficult to identify – had to be used to build the indicator

Modelling Monochamus galloprovincialis dispersal trajectories across a heterogeneous landscape to optimize monitoring by trapping networks

Context 14 The pine wood nematode (PWN), is an invasive species which was introduced into Europe in 15 1999. It represents a major economic and ecological threat to European forests. In Europe, the 16 maritime pine is the main host and Monochamus galloprovinciallis is its only vector. 17 18 Objectives 19 Our goal was to analyze the effect of landscape heterogeneity on the vector’s dispersal. We 20 further aimed at developing a new method to locate the origin of insects captured in a systematic 21 network of pheromone traps. 22 23 Methods 24 A mark-release-recapture experiment was carried out in a heterogeneous landscape combining 25 maritime pine plantations, clear-cuts and isolated patches of broadleaved and mixed forests in 26 the southwest of France. 27 Least-cost path analysis was used to model dispersal trajectories and assign friction values to 28 each land-use type in the landscape. We used the trap’s geographical coordinates, capture levels 29 and mean friction values of neighbouring patches to calculate a weighed barycentre and the 30 position of the release of marked beetlesinfo:eu-repo/semantics/submittedVersio

Drought and stand susceptibility to attacks by the European spruce bark beetle: A remote sensing approach

Several time-series analyses have demonstrated that after extreme summer droughtbark beetle damage increased. However, studies predicting stand susceptibility overlarge spatial extents are limited by technical constraints in obtaining detailed,spatially-explicit data on infestation spot occurrence.2. Using a unique dataset of georeferenced bark beetle infestation data, we testedwhether the spatial variation of local growing conditions of forest stands, topogra-phy, and landscape variables modified the local occurrence ofIps typographusinfes-tations after a severe hot drought in Central Europe.3. Bark beetle infestation occurrence depended on soil-related aridity intensity, eleva-tion, slope, and soil conditions. We showed that elevation interacted with growingconditions and topography. At low elevations, spruce forests growing on flat areasand wetter soils were more sensitive to the infestations. On the contrary, forestson steep slopes and soils with low water availability were rarely attacked. At thelandscape scale, bark beetle damage increased with host tree cover but decreasedwith compositional diversity.4. Our findings are generally consistent with the growth-differentiation balancehypothesis that predicts that trees growing under chronic dry conditions tend to bemore resistant against biotic disturbances.5. Spruce stands at low elevations located in homogeneous landscapes dominated byspruce were those more exposed to bark beetles in the initial phase of a drought-induced outbrea

La cochenille du pin maritime, Matsuccocus feytaudi, nouvelles données épidémiologiques et perspectives de lutte.

La cochenille Matsucoccus feytaudi fait son apparition en Corse en 1994. Depuis, un réseau de surveillance a été mis en place, qui a permis de suivre efficacement l'évolution de la maladie. Même si les résultats en terme de mortalité ne sont guère encourageants, des solutions de lutte préventive semblent se profiler : lutte biologique, éclaircie préventive, sélection d'arbres résistants..

Effect of the Diversity of Forests on Their Resistance to native and Alien Insect Pests

In view of the technical, economic and environmental problems raised by curative control of insect pests, greater attention should be paid to developing prevention of entomological risks in forests. An increasing number of meta-analyses and empirical studies suggest that mixed forests suffer less damage from insects than pure forests in a temperate environment. Several mechanisms explain this “associational resistance” (of forest species). The presence of non-host species in mixed forests brings about a decrease in the host tree resource, reduces their accessibility and may alter their traits limiting their colonisation and exploitation by the insect pest. Furthermore, forest species biodiversity leads to an increase in the resource and to habitats that are favourable to the natural enemies of pests and therefore to an improvement in their predatory efficiency. Rather than the wealth of species in a mixed forest, it is more the identity and relative proportions of the various species in the mix that impact their resistance to herbivores. These ecological processes based on the concept of associational resistance could be taken into account to develop alternative silvicultural practices for preserving forest health in the long term

Forest edges have high conservation value for bird communities in mosaic landscapes

A major conservation challenge in mosaic landscapes is to understand how trait-specific responses to habitat edges affect bird communities, including potential cascading effects on bird functions providing ecosystem services to forests, such as pest control. Here, we examined how bird species richness, abundance and community composition varied from interior forest habitats and their edges into adjacent open habitats, within a multi-regional sampling scheme. We further analyzed variations in Conservation Value Index (CVI), Community Specialization Index (CSI) and functional traits across the forest-edge-open habitat gradient. Bird species richness, total abundance and CVI were significantly higher at forest edges while CSI peaked at interior open habitats, i.e., furthest from forest edge. In addition, there were important variations in trait-and species-specific responses to forest edges among bird communities. Positive responses to forest edges were found for several forest bird species with unfavorable conservation status. These species were in general insectivores, understorey gleaners, cavity nesters and long-distance migrants, all traits that displayed higher abundance at forest edges than in forest interiors or adjacent open habitats. Furthermore, consistently with predictions, negative edge effects were recorded in some forest specialist birds and in most open-habitat birds, showing increasing densities from edges to interior habitats. We thus suggest that increasing landscape-scale habitat complexity would be beneficial to declining species living in mosaic landscapes combining small woodlands and open habitats. Edge effects between forests and adjacent open habitats may also favor bird functional guilds providing valuable ecosystem services to forests in long-standing fragmented landscapes