Search results for "Red"
showing 10 items of 23890 documents
Sex pheromones and trail-following pheromone in the basal termites Zootermopsis nevadensis (Hagen) and Z. angusticollis (Hagen) (Isoptera: Termopsida…
2010
In the context of an evolutionary study of the chemical communication in termites, sex pheromones and trail-following pheromones were investigated in two Termopsidae, Zootermopsis nevadensis and Z. angusticollis. In these species, in which the presence of sex-specific pheromones has been demonstrated previously, the chemical structure of the female sex pheromone has now been identified as (5E)-2,6,10-trimethylundeca-5,9-dienal and the male sex pheromone as (+)- or (-)-syn-4,6-dimethyldodecanal. The amount of sex pheromone was estimated at 5-10 ng per individual in females and 2-5 ng in males. Because these two sympatric species do not differ in their pheromonal chemical composition, reprodu…
Discriminating uniparental and biparental breeding strategies by monitoring nest temperature
2017
10 pages; International audience; Birds exhibit a wide diversity of breeding strategies. During incubation or chick-rearing, parental care can be either uniparental, by either the male or the female, or biparental. Understanding the selective pressures that drive these different strategies represents an exciting challenge for ecologists. In this context, assigning the type of parental care at the nest (e.g. biparental or uniparental incubation strategy) is often a prerequisite to answering questions in evolutionary ecology. The aim of this study was to produce a standardized method unequivocally to assign an incubation strategy to any Sanderling Calidris alba nest found in the field by moni…
Faster acquisition of symbiotic partner by common mycorrhizal networks in early plant life stage
2016
Arbuscular mycorrhizal (AM) fungi usually improve plant performance yet our knowledge about their effects on seed germination and early plant establishment is very limited. We performed a factorial greenhouse experiment where the seeds from four low Arctic cooccurring mycorrhizal herbs (Antennaria dioica, Campanula rotundifolia, Sibbaldia procumbens, and Solidago virgaurea) were germinated alone or in the vicinity of an adult Sibbaldia plant with or without AM fungi; given either as spores or being present in a common mycorrhizal network (CMN). Three different AM fungal species were examined to assess species-specific differences in symbiont acquisition rate. Out of the four plant species i…
Carbon partitioning in a walnut-maize agroforestry system through arbuscular mycorrhizal fungi
2020
National audience; In tree-based intercropping systems, roots of trees and crops are interacting and could influence ecosystem services provided by soil microorganisms. Here, the analysis of diversity of arbuscular mycorrhiza fungi (AMF) associated with roots of walnut and maize reveals differences. Of interest, Funneliformis genus is mainly associated with maize roots, and one OTU related to an uncultured Glomus, might form a common mycorrhizal network linking roots of both plants. In addition, the analysis of 13C of mycelium living in the surrounding environment of roots, suggest that part of the carbon derived from walnut trees could be transferred to maize plants. Our results suggest th…
Last tesserae of a fading mosaic: floristic census and forest vegetation survey at Parche di Bilello (south-western Sicily, Italy), a site needing ur…
2021
This paper illustrates the botanic heritage of Parche di Bilello, a site located in the municipality of Castelvetrano. The study area hosts several woodland fragments dominated by Olea europaea var. sylvestris, Quercus suber and Quercus ilex, respectively. According to historical data, these nuclei represent the last remnants of an open forestland which covered a much wider coastal area between Mazara del Vallo and Sciacca until the end of Middle Age. Phytosociological relevés were focused on these forest nuclei, probably the most representative of south-western Sicily, which correspond to three habitats included in the 92/43 EEC Directive (9320, 9330 and 9340, respectively) and represent t…
Mediterranean Bioconstructions Along the Italian Coast
2018
Marine bioconstructions are biodiversity-rich, three-dimensional biogenic structures, regulating key ecological functions of benthic ecosystems worldwide. Tropical coral reefs are outstanding for their beauty, diversity and complexity, but analogous types of bioconstructions are also present in temperate seas. The main bioconstructions in the Mediterranean Sea are represented by coralligenous formations, vermetid reefs, deep-sea cold-water corals, Lithophyllum byssoides trottoirs, coral banks formed by the shallow-water corals Cladocora caespitosa or Astroides calycularis, and sabellariid or serpulid worm reefs. Bioconstructions change the morphological and chemicophysical features of prima…
Selective incorporation of dissolved organic matter (DOM) during sea ice formation
2013
This study investigated the incorporation of DOM from seawater into >2 day-old sea ice in tanks filled with seawater alone or amended with DOM extracted from the microalga, Chlorella vulgaris. Optical properties, including chromophoric DOM (CDOM) absorption and fluorescence, as well as concentrations of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), dissolved carbohydrates (dCHOs) and dissolved uronic acids (dUAs) were measured. Enrichment factors (EFs), calculated from salinity-normalized concentrations of DOM in bulk ice, brine and frost flowers relative to under-ice water, were generally >1. The enrichment factors varied for different DOM fractions: EFs were the lowest fo…
Occupation of wood warbler Phylloscopus sibilatrix nests by Myrmica and Lasius ants
2018
Bird nests can provide habitats for various invertebrates, including ectoparasites, scavengers, and predators. Records of ants associating with active bird nests mostly involve the insects searching for food, with some exceptional records of ants raising their broods (eggs, larvae or pupae) within songbird nests in nest-boxes or tree cavities. We present data for a previously undocumented, but apparently regular, occurrence of ants and their broods within the active nests of a songbird, the wood warbler Phylloscopus sibilatrix (Bechstein, 1793), which builds domed nests on the ground in European forests. Systematic recording found ants, mostly Myrmica ruginodis Nylander, 1846, in 43% of 80 …
Camouflage accuracy in Sahara–Sahel desert rodents
2020
1. Camouflage helps animals to hide from predators and is therefore key to survival. Although widespread convergence of animal phenotypes to their natural environment is well-established, there is a lack of knowledge about how species compromise camouflage accuracy across different background types in their habitat.2. Here we tested how background matching has responded to top–down selection by avian and mammalian predators using Sahara–Sahel desert rodents in North Africa.3. We show that the fur colouration of several species has become an accurate match to different types of desert habitats. This is supported by a correlation analysis of colour and pattern metrics, investigation of animal…
Lichen communities on Populus tremula are affected by the density of Picea abies
2021
Questions Aspen (Populus tremula) is declining in the old‐growth forests of boreal Fennoscandia. This threatens the numerous taxa that are dependent on old aspens, including many epiphytic lichens. Potential methods to aid epiphytic lichens on aspen are centered around treatments which affect the density of Norway spruce (Picea abies). In this study, we investigated how epiphytic lichen communities on aspen are affected by the variation of spruce density in the immediate vicinity of the focal aspen. Location Southern boreal forests in Finland. Methods We recorded the occurrence of lichens from 120 aspens in 12 semi‐natural forest sites. We used spruce basal area as the measure for spruce de…