Search results for "ASA"

Genetic variation in the mechanisms of direct mutual interference in a parasitic wasp: consequences in terms of patch-time allocation

2004

Summary 1. Direct mutual interference between insect parasitoids has always been considered to have major consequences for the population dynamics of parasitoid‐host systems. Furthermore, patch time allocation has also always been presented as an important behavioural component that is closely involved in the demographic features of host‐ parasitoid interactions. 2. Based on a detailed analysis of within-patch interactions between Trissolcus basalis (Hymenoptera: Scelionidae) females, the present study aimed to understand accurately how direct mutual interference can influence patch time allocation in this species. 3. The genetic variation in the behavioural mechanisms involved in the inter…

On personality, energy metabolism and mtDNA introgression in bank voles

2014

Consistent interindividual differences in behaviour, or animal personality, are emerging as an important determinant of a wide range of life history traits and fitness. Individual behaviour, however, may be constrained by between-individual variability in energy metabolism and may become unstable owing to intrinsic and extrinsic stressors. Here we tested the relationship between personality and physiology using wild-caught bank voles, Myodes glareolus, that varied according to mtDNA type (original or introgressed from Myodes rutilus). Personality traits and their within-individual consistency were assessed using an open field test and basal metabolic rate (BMR) was measured in an open-flow …

Basal ice formation in snow cover in Northern Finland between 1948 and 2016

2018

Sea temperature effects on depth use and habitat selection in a marine fish community.

2021

14 pages, 7 figures, 2 tables.-- Open access

Major trends in stem anatomy and growth forms in the perianth-bearing Piperales, with special focus on Aristolochia.

2014

International audience; BACKGROUND AND AIMS: The order Piperales has the highest diversity of growth forms among the earliest angiosperm lineages, including trees, shrubs, climbers and herbs. However, within the perianth-bearing Piperales (Asarum, Saruma, Lactoris, Hydnora, Prosopanche, Thottea and Aristolochia), climbing species only occur in the most species-rich genus Aristolochia. This study traces anatomical and morphological traits among these lineages, to detect trends in growth form evolution and developmental processes. METHODS: Transverse stem sections of different developmental stages of representatives of Asarum, Saruma, Lactoris, Hydnora, Thottea and Aristolochia were compared …

Windthrow in streamside key habitats: Effects of buffer strip width and selective logging

2020

Abstract Streamside forests are preserved from clear-cut logging in production forests and protected with uncut buffer strips in many countries. However, buffer strips often remain narrow due to economic reasons and, therefore, provide weak protection against adverse edge effects of clear-cuts and are vulnerable to windthrow. Selective logging of buffer strips is sometimes allowed to reduce their costs, but the decreased tree density may expose the buffer to higher occurrence of windthrow. We used a replicated two-factor experiment to assess the effects of buffer width (15 m or 30 m) and selective logging (0% or 30% of the basal area removed) on the risk of windthrow in boreal streamside fo…

Introgression of mitochondrial DNA among Myodes voles: consequences for energetics?

2011

Abstract Background Introgression of mitochondrial DNA (mtDNA) is among the most frequently described cases of reticulate evolution. The tendency of mtDNA to cross interspecific barriers is somewhat counter-intuitive considering the key function of enzymes that it encodes in the oxidative-phosphorylation process, which could give rise to hybrid dysfunction. How mtDNA reticulation affects the evolution of metabolic functions is, however, uncertain. Here we investigated how morpho-physiological traits vary in natural populations of a common rodent (the bank vole, Myodes glareolus) and whether this variation could be associated with mtDNA introgression. First, we confirmed that M. glareolus ha…

Elevated oxidative stress in pied flycatcher nestlings of eumelanic foster fathers under low rearing temperatures

2019

Striking variation in melanin coloration within natural populations is likely due to the different fitness outcomes of alternative phenotypes in varying environmental conditions. There are two types of melanin: eumelanins yield blackish hues, whereas pheomelanins yield reddish hues. The production of eumelanins requires low levels of glutathione (GSH), which is the most important intracellular antioxidant, whereas the production of pheomelanins requires high levels of GSH. We investigated the oxidative status of male pied flycatchers (Ficedula hypoleuca) with different degrees of melanin coloration under different temperatures during the nestling period. Moreover, we assessed the oxidative …

The evolution of sperm morphometry in pheasants

2007

7 pages; International audience; Post-copulatory sexual selection is thought to be a potent evolutionary force driving the diversification of sperm shape and function across species. In birds, insemination and fertilization are separated in time and sperm storage increases the duration of sperm-female interaction and hence the opportunity for sperm competition and cryptic female choice. We performed a comparative study of 24 pheasant species (Phasianidae, Galliformes) to establish the relative importance of sperm competition and the duration of sperm storage for the evolution of sperm morphometry (i.e. size of different sperm traits). We found that sperm size traits were negatively associat…

Living and Dead Aboveground Biomass in Mediterranean Forests: Evidence of Old-Growth Traits in a Quercus pubescens Willd. s.l. Stand

2017

For a long time, human impact has deeply simplified most of the forest ecosystems of the Mediterranean Basin. Here, forests have seldom had the chance to naturally develop a complex and multilayered structure, to host large and old trees and rich biological communities, approaching old-growth conditions. Also for this reason, limited information is currently available about Mediterranean old-growth forests, particularly with regard to deadwood. The main aim of this work is to help fill this critical knowledge gap. In Sicily (Italy), we identified a Quercus pubescens forest that seemed to show some typical old-growth features. Total living volume (360 m3 ha−1) and basal area (34 m2 ha−1) wer…