Search results for "Priming effect"
showing 10 items of 12 documents
Previous fire occurrence, but not fire recurrence, modulates the effect of charcoal and ash on soil C and N dynamics in Pinus pinaster Aiton forests.
2021
Abstract Understanding the effects of fire history on soil processes is key to characterise their resistance and resilience under future fire events. Wildfires produce pyrogenic carbonaceous material (PCM) that is incorporated into the soil, playing a critical role in the global carbon (C) cycle, but its interactions with soil processes are poorly understood. We evaluated if the previous occurrence of wildfires modulates the dynamic of soil C and nitrogen (N) and microbial community by soil ester linked fatty acids, after a new simulated low-medium intensity fire. Soils with a different fire history (none, one, two or three fires) were heat-shocked and amended with charcoal and/or ash deriv…
Le Priming Effect dans le sol : mécanismes, acteurs et conséquences sur les services écosystémiques dans un contexte de changement global
2022
The priming effect (PE) is a key mechanism contributing to the carbon balance of the soil ecosystem. Almost 100 years of research since its discovery in 1926 have led to a rich body of scientific publications to identify the drivers and mechanisms involved. A few review articles have summarised the acquired knowledge; the last major one was published in 2010. Since then, knowledge on the soil microbial communities involved in PE and in PE + C sequestration mechanisms has been considerably renewed.This article reviews current knowledge on soil PE to state to what extent new insights may improve our ability to understand and predict the evolution of soil C stocks. We propose a framework to un…
A time estimation task as a possible measure of emotions: difference depending on the nature of the stimulus used
2015
Objective: Time perception is fundamental for human experience. A topic which has attracted the attention of researchers for long time is how the stimulus sensory modality (e.g., images vs. sounds) affects time judgments. However, so far, no study has directly compared the effect of two sensory modalities using emotional stimuli on time judgments. Methods: In the present two studies, healthy participants were asked to estimate the duration of a pure sound preceded by the presentation of odors vs. emotional videos as priming stimuli (implicit emotion-eliciting task). During the task, skin conductance (SC) was measured as an index of arousal. Results: Olfactory stimuli resulted in an increase…
Auditory Emotion Word Primes Influence Emotional Face Categorization in Children and Adults, but Not Vice Versa
2018
In order to assess how the perception of audible speech and facial expressions influence one another for the perception of emotions, and how this influence might change over the course of development, we conducted two cross-modal priming experiments with three age groups of children (6-, 9-, and 12-years old), as well as college-aged adults. In Experiment 1, 74 children and 24 adult participants were tasked with categorizing photographs of emotional faces as positive or negative as quickly as possible after being primed with emotion words presented via audio in valence-congruent and valence-incongruent trials. In Experiment 2, 67 children and 24 adult participants carried out a similar cate…
The Clock'N Test as a Possible Measure of Emotions: Normative Data Collected on a Non-clinical Population.
2016
International audience; Objective: At present emotional experience and implicit emotion regulation (IER) abilities are mainly assessed though self -reports, which are subjected to several biases. The aim of the present studies was to validate the Clock'N test, a recently developed time estimation task employing emotional priming to assess implicitly emotional reactivity and IER. Methods: In Study 1, the Clock' N test was administered to 150 healthy participants with different age, laterality and gender, in order to ascertain whether these factors affected the test results. In phase 1 participant were asked to judge the duration of seven sounds. In phase 2, before judging the duration of the…
High microbial diversity promotes soil ecosystem functioning
2018
ABSTRACT In soil, the link between microbial diversity and carbon transformations is challenged by the concept of functional redundancy. Here, we hypothesized that functional redundancy may decrease with increasing carbon source recalcitrance and that coupling of diversity with C cycling may change accordingly. We manipulated microbial diversity to examine how diversity decrease affects the decomposition of easily degradable (i.e., allochthonous plant residues) versus recalcitrant (i.e., autochthonous organic matter) C sources. We found that a decrease in microbial diversity (i) affected the decomposition of both autochthonous and allochthonous carbon sources, thereby reducing global CO 2 e…
Response of soil bacterial communities to the incorporation of crop residues : influence of agricultural practices and link with the soil biological …
2010
The effect of the location of wheat residues (soil surface vs. incorporated in soil) on their decomposition and on soil bacterial communities was investigated by the means of a field experiment. Bacterial-Automated Ribosomal Intergenic Spacer Analysis (B-ARISA) of DNA extracts from residues, detritusphere (soil adjacent to residues), and bulk soil evidenced that residues constitute the zone of maximal changes in bacterial composition. However, the location of the residues influenced greatly their decomposition and the dynamics of the colonizing bacterial communities. Sequencing of 16S rRNA gene in DNA extracts from the residues at the early, middle, and late stages of degradation confirmed …
Influence of microbial diversity on soil organic carbon dynamics highlighted by a 13C-labelling technique
2012
Soil organic matter (SOM) represents the main pool of carbon within the biosphere, estimated at roughly twice that in atmospheric CO2. In agrosystems, organic amendments are common to maintain soil C stocks. However, recent studies have revealed that these practices can lead to a priming effect, corresponding to enhanced release of CO2 into the atmosphere, due to over-mineralisation of soil organic carbon. Therefore, appropriate decisions regarding organic input management require better understanding of the biogeochemical cycles related to SOM dynamics. As soil microorganisms are major actors in SOM turnover, their diversity is likely to influence SOM dynamics. In this context, the relatio…
Soil microbial networks: what is the relationship with plants?
2020
International audience; Since a long time, the interactions between soil microbes and plant roots are intensively investigated to decipher the role of microorganisms in the growth and the maintenance of plants in a multitude of environmental conditions as climatic stress, agricultural practices or pathogenic/parasitic invasions. Beyond their intimate relationships, the soil microbial communities influence and are influenced by the aboveground vegetation. The interaction/co-occurrence networks are a relatively new look on the soil microbial communities. This look integrates the most comprehensively the community complexity, provides a more complete information on the community and seems to b…
Priming effect increases with depth in a boreal forest soil
2016
Abstract Climate warming increases labile carbon (C) inputs to soil through increased photosynthesis and C allocation belowground. This could counterintuitively lead to losses of soil C via priming effects (PE): the stimulation of soil organic matter (SOM) decomposition caused by labile C addition. Systematic quantification of PEs in different ecosystems is needed. We measured PEs of free-living soil microbes in different layers of a boreal forest soil, and found that the relative magnitude of the PE increased with soil depth. The relationship between relative PE and the added glucose amount also depended on the soil layer. Our results indicate that the decomposition of SOM in deeper soil l…