Search results for "Biotic component"
showing 10 items of 127 documents
Metacommunities from bacteria to birds: stronger environmental selection in mediterranean than in tropical ponds
2021
AbstractThe metacommunity concept provides a theoretical framework that aims at explaining organism distributions by a combination of environmental filtering, dispersal and drift. With the development of statistical tools to quantify and partially isolate the role of each of these processes, empirical metacommunity studies have multiplied worldwide. However, few works attempt a multi-taxon approach and even fewer compare two distant biogeographical regions using the same methodology. Under this framework, we tested the expectation that temperate (mediterranean-climate) pond metacommunities would be more influenced by environmental and spatial processes than tropical ones, because of stronge…
Starvation can diversify the population structure and virulence strategies of an environmentally transmitting fish pathogen.
2013
Background Generalist bacterial pathogens, with the ability for environmental survival and growth, often face variable conditions during their outside-host period. Abiotic factors (such as nutrient deprivation) act as selection pressures for bacterial characteristics, but their effect on virulence is not entirely understood. “Sit and wait” hypothesis expects that long outside-host survival selects for increased virulence, but maintaining virulence in the absence of hosts is generally expected to be costly if active investments are needed. We analysed how long term starvation influences bacterial population structure and virulence of an environmentally transmitting fish pathogen Flavobacteri…
The Global Soil Mycobiome consortium dataset for boosting fungal diversity research
2021
This version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at https://doi.org/10.1007/s13225-021-00493-7. Fungi are highly important biotic components of terrestrial ecosystems, but we still have a very limited understanding about their diversity and distribution. This data article releases a global soil fungal dataset of the Global Soil Mycobiome consortium (GSMc) to boost further research in fungal diversity, biogeography and macroecology. The dataset comprises 722,682 fu…
Filamentous fungi transported by birds during migration across the mediterranean sea.
2013
The potential for the transport and diffusion of some pathogenic microorganisms by migratory birds is of concern. Migratory birds may be involved in the dispersal of microorganisms and may play a role of mechanical and biological vectors. The efficiency of dispersal of pathogenic microorganisms depends on a wide range of biotic and abiotic factors that influence the survival or disappearance of a given agent in a geographical area. In the present study, 349 migratory birds were captured in four sites (Mazara del Vallo, Lampedusa, Ustica and Linosa), representing the main stop-over points during spring and autumnal migration, and analyzed for the presence of filamentous fungi. A total of 2,3…
Biometric variation in three strains of Brachionus plicatilis as a direct response to abiotic variables
1987
Morphometric variation in three clones of Brachionus plicatilis cultured at 20°C, 25°C and 30°C, and 9‰, 12‰ and 24‰ salinity was analysed. Size appeared to be largely under genetic control and this defined the narrow limits within which variation due to abiotic factors could occur. Temperature had a significant effect on size, but affected the three clones differently. The most general effect of temperature was a reduction in size which levelled off as the temperature rose. Of the measurements taken, only distance between the median spines was affected by salinity. An important inter-relationship between the effects of temperature and salinity was also detected.
Home advantage? Decomposition across the freshwater-estuarine transition zone varies with litter origin and local salinity
2015
Expected increases in the frequency and intensity of storm surges and river flooding may greatly affect the relative salinity of estuarine environments over the coming decades. In this experiment we used detritus from three contrasting environments (marine Fucus vesiculosus; estuarine Spartina anglica; terrestrial Quercus robur) to test the prediction that the decomposition of the different types of litter would be highest in the environment with which they are associated. Patterns of decomposition broadly fitted our prediction: Quercus detritus decomposed more rapidly in freshwater compared with saline conditions while Fucus showed the opposite trend; Spartina showed an intermediate respon…
Ocean acidification bends the mermaid's wineglass
2015
Ocean acidification lowers the saturation state of calcium carbonate, decreasing net calcification and compromising the skeletons of organisms such as corals, molluscs and algae. These calcified structures can protect organisms from predation and improve access to light, nutrients and dispersive currents. While some species (such as urchins, corals and mussels) survive with decreased calcification, they can suffer from inferior mechanical performance. Here, we used cantilever beam theory to test the hypothesis that decreased calcification would impair the mechanical performance of the green alga Acetabularia acetabulum along a CO 2 gradient created by volcanic seeps off Vulcano, Italy. Cal…
Mussels as a model system for integrative ecomechanics.
2015
Copyright © 2015 by Annual Reviews. All rights reserved. Mussels form dense aggregations that dominate temperate rocky shores, and they are key aquaculture species worldwide. Coastal environments are dynamic across a broad range of spatial and temporal scales, and their changing abiotic conditions affect mussel populations in a variety of ways, including altering their investments in structures, physiological processes, growth, and reproduction. Here, we describe four categories of ecomechanical models (biochemical, mechanical, energetic, and population) that we have developed to describe specific aspects of mussel biology, ranging from byssal attachment to energetics, population growth, an…
Growth and defense in deciduous trees and shrubs under UV-B
2005
Abstract Reflection by waxy or resinous surface structures and hairs, repair reactions of biomolecules and induction of different sheltering components provide the means of plant protection from harmful solar UV-B radiation. Secondary products, especially flavonoids and phenolic acids as defense components are also important in plant tolerance to UV-B, fulfilling the dual role as screens that reduce UV-B penetration in plant tissues, and as antioxidants protecting from damage by reactive oxidant species. Plants are sensitive to UV-B radiation, and this sensitivity can be even more clone-specific than species-specific. The results available in the literature for deciduous trees and shrubs in…
Broomrape weeds. Underground mechanisms of parasitism and associated strategies for their control: a review
2016
prod 2018-285d SPE GESTAD Agrosup INRA CT?; International audience; Broomrapes are plant-parasitic weeds which constitute one of the most difficult-to-control of all biotic constraints that affect crops in Mediterranean, central and eastern Europe, and Asia. Due to their physical and metabolic overlap with the crop, their underground parasitism, their achlorophyllous nature, and hardly destructible seed bank, broomrape weeds are usually not controlled by management strategies designed for non-parasitic weeds. Instead, broomrape are in a current state of intensification and spread due to lack of broomrape-specific control programs, unconscious introduction to new areas and may be decline of …