scholarly journals Comparing statistical and mechanistic models to identify the drivers of mortality within a rear-edge beech population

2019 ◽  
Author(s):  
Cathleen Petit-Cailleux ◽  
Hendrik Davi ◽  
François Lefèvre ◽  
Joseph Garrigue ◽  
Jean-André Magdalou ◽  
...  
Keyword(s):  
Tree Mortality ◽  
European Beech ◽  
Temporal Variations ◽  
Individual Variability ◽  
Rear Edge ◽  
Individual Vulnerability ◽  
Individual Probability ◽  
Crown Defoliation ◽  
The Individual ◽  
The Impact

AbstractSince several studies have been reporting an increase in the decline of forests, a major issue in ecology is to better understand and predict tree mortality. The interactions between the different factors and the physiological processes giving rise tree mortality, as well as the inter-individual variability in mortality risk, still need to be better assessed.This study investigates mortality in a rear-edge population of European beech (Fagus sylvatica L.) using a combination of statistical and process-based modelling approaches. Based on a survey of 4323 adult beeches since 2002 within a natural reserve, we first used statistical models to quantify the effects of competition, tree growth, size, defoliation and fungi presence on mortality. Secondly, we used an ecophysiological process-based model (PBM) to separate out the different mechanisms giving rise to temporal and inter-individual variations in mortality by simulating depletion of carbon stocks, loss of hydraulic conductance and damage due to late frosts in response to climate.The combination of all these simulated processes was associated with the temporal variations in the population mortality rate. The individual probability of mortality decreased with increasing mean growth, and increased with increasing crown defoliation, earliness of budburst, fungi presence and increasing competition, in the statistical model. Moreover, the interaction between tree size and defoliation was significant, indicating a stronger increase in mortality associated to defoliation in smaller than larger trees. Finally, the PBM predicted a higher conductance loss together with a higher level of carbon reserves for trees with earlier budburst, while the ability to defoliate the crown was found to limit the impact of hydraulic stress at the expense of the accumulation of carbon reserves.We discuss the convergences and divergences obtained between statistical and process-based approaches and we highlight the importance of combining them to characterize the different processes underlying mortality, and the factors modulating individual vulnerability to mortality.

European beech is a net annual source of methane (CH4)

2021 ◽  
Author(s):  
Katerina Machacova ◽  
Hannes Warlo ◽  
Kateřina Svobodová ◽  
Thomas Agyei ◽  
Tereza Uchytilová ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Seasonal Dynamics ◽  
Forest Floor ◽  
Greenhouse Gas Emission ◽  
European Beech ◽  
Individual Variability ◽  
Spatiotemporal Variability ◽  
Vegetation Season ◽  
Dormant Season ◽  
The Impact

<p>Trees are known to be sources of methane (CH<sub>4</sub>), an important greenhouse gas, into the atmosphere. However, still little is known about the seasonality of the tree stem CH<sub>4</sub> fluxes, particularly for the dormant season, and about the impact of environmental parameters on this gas exchange. This makes the estimation of net annual ecosystem CH<sub>4</sub> fluxes difficult.</p><p>We determined seasonal dynamics of CH<sub>4</sub> exchange of mature European beech stems (<em>Fagus sylvatica</em>) and of adjacent forest floor in a temperate montane forest of White Carpathians, Czech Republic, from November 2017 to December 2018. We used static chamber methods and gas chromatographic analyses. We aimed to understand the unknown role in seasonal changes of CH<sub>4</sub> fluxes of these forests, and the spatiotemporal variability of the tree fluxes.</p><p>The beech stems were net annual sources for atmospheric CH<sub>4</sub>, whereas the forest floor was a predominant sink for CH<sub>4</sub>. The stem CH<sub>4</sub> emissions showed high inter-individual variability and clear seasonality following the stem CO<sub>2</sub> efflux. The fluxes of CH<sub>4</sub> peaked during the vegetation season, and remained low but significant to the annual totals during winter dormancy. By contrast, the forest floor CH<sub>4</sub> uptake followed an opposite flux trend with low CH<sub>4</sub> uptake detected in the winter dormant season and elevated CH<sub>4</sub> uptake during the vegetation season. Based on our preliminary analyses, the detected high spatial variability in stem CH<sub>4</sub> emissions can be explained neither by the CH<sub>4</sub> exchange at the forest floor level, nor by soil CH<sub>4</sub> concentrations, soil water content and soil temperature, all measured in vertical soil profiles close to the studied trees.</p><p>European beech trees, native and widely spread species of Central Europe, seem to markedly contribute to the seasonal dynamics of the ecosystem CH<sub>4</sub> exchange, and their CH<sub>4</sub> fluxes should be included into forest greenhouse gas emission inventories.</p><p> </p><p><em>Acknowledgement</em></p><p><em>This research was supported by the Czech Science Foundation (17-18112Y), National Programme for Sustainability I (LO1415), CzeCOS (LM2015061), and SustES - Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797). We thank Libor Borák and Leszek Dariusz Laptaszyński for their technical and field support.</em></p><p> </p>

Graduates and Active Labour Market Programmes: Evidence of Deactivation

2012 ◽  
Vol 26 (2) ◽  
pp. 107-113 ◽  
Author(s):  
Simon Stephens
Keyword(s):  
Labour Market ◽  
Empirical Studies ◽  
Short Term ◽  
Active Labour ◽  
Individual Probability ◽  
The Individual ◽  
The Impact ◽  
Depth Interviews ◽  
Active Labour Market Programmes ◽  
Job Prospects

This paper explores the experiences of graduates who participated in a range of Active Labour Market Programmes (ALMPs) in Ireland. The paper uses narrative structuring to provide an enhanced understanding of the graduates' experiences. A review of the literature indicates that most empirical studies of the effects of ALMPs are quantitative. Typically, the studies evaluate whether participation in a programme increases the individual probability of leaving unemployment. This paper argues that other, softer outcomes must also be studied if the impact of ALMPs is to be properly understood. The author therefore adopts a qualitative approach to examine the impact of ALMPs on graduates. The data collected during in-depth interviews indicate a mixed picture. While graduates found their experiences during the ALMPs positive in the main, the impact on their outlook and job prospects is not encouraging. Too often, the graduates express a view that the ALMPs are a ‘short-term fix’, offering little prospect of secure employment. The paper identifies the potential problem of deactivation in addition to the problems of deadweight loss, substitution and displacement reported by Fraser (1999).

scholarly journals Crown defoliation decreases reproduction and wood growth in a marginal European beech population

2018 ◽  
Author(s):  
Sylvie Oddou-Muratorio ◽  
Cathleen Petit-Cailleux ◽  
Valentin Journé ◽  
Matthieu Lingrand ◽  
Jean-André Magdalou ◽  
...  
Keyword(s):  
Basal Area ◽  
High Growth ◽  
European Beech ◽  
Population Level ◽  
Forest Tree ◽  
List Type ◽  
Female Fecundity ◽  
Large Trees ◽  
Crown Defoliation ◽  
The Impact

ABSTRACTAbiotic and biotic stresses related to climate change have been associated to increased crown defoliation, decreased growth and a higher risk of mortality in many forest tree species, but the impact of stresses on tree reproduction and forest regeneration remains understudied. At dry, warm margin of species distributions, flowering, pollination and seed maturation processes are expected to be affected by drought, late frost and other stresses, eventually resulting in reproduction failure. Moreover, inter-individual variations in reproductive performances versus other performances (growth, survival) could have important consequences on population’s dynamics.We investigated the relationships between individual crown defoliation, growth and reproduction in a drought-prone population of European beech, Fagus sylvatica. We used a spatially explicit mating model and marker-based parentage analyses to estimate effective female and male fecundities of 432 reproductive trees, which were also monitored for basal area increment and crown defoliation over nine years.Female and male fecundities markedly varied among individuals, more than did growth. Both female fecundity and growth decreased with increasing crown defoliation and competition and increased with size. Male fecundity only responded to competition, and decreased with increasing competition. Moreover, the negative effect of defoliation on female fecundity was size-dependent, with a slower decline in female fecundity with increasing defoliation for the large individuals. Finally, a trade-off between growth and female fecundity was observed in response to defoliation: some large trees maintained significant female fecundity at the expense of reduced growth in response to defoliation, while some other defoliated trees rather maintained high growth at the expense of reduced female fecundity.Synthesis. Our results suggest that while decreasing their growth, some large defoliated trees still contribute to reproduction through seed production and pollination. This non-coordinated decline of growth and fecundity at individual-level in response to stress may compromise the evolution of stress-resistance traits at population level, and increase forest tree vulnerability.

scholarly journals Testing and Validating Against Historic Spills

2021 ◽  
pp. 59-86
Author(s):  
Cathrine Stephansen ◽  
Anders Bjørgesæter ◽  
Odd Willy Brude ◽  
Ute Brönner ◽  
Tonje Waterloo Rogstad ◽  
...  
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
Individual Vulnerability ◽  
Resource Data ◽  
Using Data ◽  
Set Up ◽  
The Individual ◽  
Acute Results ◽  
The Impact ◽  
Impact Models

AbstractTo validate the predictive capability of ERA Acute, a study was carried out using data from two well-studied historic oil spills, the Exxon Valdez Oil Spill (EVOS) and the Deepwater Horizon Oil Spill (DHOS) incidents. Results from the case studies with ERA Acute were compared to the impact estimates and recovery observations that have been reported in the extensive research following the two incidents. Resource data relevant for each of the two incidents were reconstructed within the analysis area. Performance boundaries were set up for evaluating the ERA Acute results, based on the ranges of the impact and recovery estimates reported in the post-spill assessments. Validation of an oil spill ERA model against post-spill assessments of historic spills is a challenging exercise due to scientific limitations of both. ERA Acute performed satisfactorily compared to the performance boundaries and the study gave useful insight into the predictive capabilities of ERA Acute. The results from the study were used to evaluate between two different impact models and to increase the individual vulnerability of cetaceans.

Frequency of Severe Attacks in Migraine Sufferers of the Gazel Cohort

Cephalalgia ◽  
1997 ◽  
Vol 17 (8) ◽  
pp. 863-866 ◽  
Author(s):  
P Michel ◽  
B Dubroca ◽  
JF Dartigues ◽  
A El Hasnaoui ◽  
Henry
Keyword(s):  
Treatment Strategies ◽  
Individual Variability ◽  
Measurement Tool ◽  
Severe Attack ◽  
Migraine Sufferer ◽  
Definition Of ◽  
The Individual ◽  
The Impact ◽  
Severe Migraine ◽  
Very High

The concept of severe migraine was raised to define migraineurs most in need of care and for use in clinical practice. We aimed to measure the frequency of severe attacks in a working sample of 276 migraine sufferers using a diary over a 3-month period. Migraine sufferers recorded each attack's clinical features, the degree of their disability, their use of drugs and the effectiveness of the drugs. Since the definition of severe attack is not standardized, we studied the impact of different definitions on the frequency. The frequency of severe attacks was 0.9% and appeared to be very sensitive to the definitions, ranging between 0.4 and 13%. In France, the extrapolated number of severe attacks is nearly one million out of a total of 115 million. In the migraineurs who had had at least one severe attack, the individual variability of intensity, duration or disability was very high, so the proportion of severe attacks in a given sufferer was low—between 15% and 50%. We conclude that the global concept of severe migraine is not relevant and should be split into two componentssevere attack and severe migraine sufferer. The goals are different, too. Regarding treatment, for example, the severe attack concept is more valid for acute treatment strategies, whereas the severe migraine sufferer concept should be preferred to determine the need for prophylactic treatment. Since much work is being done nowadays to define a rate treatment strategies, definition of the criteria of severe attack and validation of a measurement tool should be a priority.

scholarly journals The Impact of Gender on Unemployment: Cross‑country and Within‑country Analysis of the European Labour Markets during Economic Recession

2020 ◽  
pp. 81-96
Author(s):  
Tatiana Medková
Keyword(s):  
Labour Force ◽  
Economic Recession ◽  
Labour Markets ◽  
Individual Probability ◽  
Cook’S Distance ◽  
Country Analysis ◽  
Cross Country ◽  
The Individual ◽  
Cook's Distance ◽  
The Impact

This paper investigates the impact of gender on the individual probability of being unemployed and makes a cross‑country comparison across 13 European countries during the European recession. Applying a general logit model for each country and capital, whilst controlling for the year, as well as for individual and regional characteristics, the probability of unemployment was estimated using individual labour force data from 2011 to 2014. Cook’s distance is used to examine the differences between labour markets of capital regions (or cities) and non‑capital regions. Using the size of Cook’s distance, models are calibrated, and models which include the degree of urbanization and occupation type are evaluated. The results are presented in the form of a spatial map and show that gender affects the probability of unemployment in the majority of the analysed countries. Overall, the effect is lower in capital than in non‑capital regions.

scholarly journals IMPACT OF DROUGHT AND SITE CHARACTERISTICS ON VITALITY AND RADIAL GROWTH OF CEDRUS ATLANTICA MANETTI IN THE OUARSENIS MASSIF (ALGERIA)

AGROFOR ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Mohamed SARMOUM ◽  
Rafael NAVARRO-CERRILLO ◽  
Frédéric GUIBAL ◽  
Fatiha ABDOUN
Keyword(s):  
Radial Growth ◽  
Tree Mortality ◽  
Climatic Factors ◽  
Ring Width ◽  
Cedrus Atlantica ◽  
Site Characteristics ◽  
Varied Range ◽  
The Individual ◽  
Steep Slopes ◽  
The Impact

This work investigates the impact of drought and site characteristics on vitality and radial growth of Atlas cedar (Cedrus atlantica Manetti) in Ouarsenis cedar forests (Algeria). The choice of this zone was dictated by the appearance of the phenomenon of decline since the 1980s and the lack of study on this subject. Our hypothesis seeks to understand how climatic factors interacted with site characteristics affected radial growth and vitality of Atlas cedar. We used the dendroecological approach where 09 populations of Atlas cedar distributed on the two cedars of Ouarsenis (Theniet El Had and Ain Antar) and covering a varied range of environmental conditions (substrate, altitude, exposure) were studied. The climatic signal recorded in ring-width series of Atlas cedar trees was investigated by bootstrapped response function over the period 1936-2010. The results show a good agreement between the individual curves and those of mean site chronologies, which reflects the influence of climatic factors on tree radial growth. Atlas cedar is very sensitive to rainfall fluctuations throughout the year. This sensitivity is more pronounced for populations located at low altitude, on steep slopes and on sand stone or marl substrates. The dry years induced a significant radial growth decline and triggered massive tree mortality, particularly in 1983, 1984, 1988, 1994 and 2002. The vitality of the species seems to be conditioned by the frequency of drought years.

scholarly journals Participatory research in a pandemic: The impact of Covid-19 on co-designing research with autistic people

2021 ◽  
pp. 147332502110401
Author(s):  
Danielle Rudd ◽  
Se Kwang Hwang
Keyword(s):  
Social Work ◽  
Social Research ◽  
Research Priorities ◽  
Critical Approach ◽  
Social Work Research ◽  
Social Work Values ◽  
Individual Vulnerability ◽  
Autistic People ◽  
The Individual ◽  
The Impact

Social work research should adopt a critical approach to research methodology, opposing oppression that is reproduced through epistemological assumptions or research methods and processes. However, traditional approaches to autism research have often problematised and pathologized autistic 1 individuals, reinforcing autistic people’s positions as passive subjects. This has resulted in autistic people being largely excluded from the production of knowledge about autism, and about the needs of autistic people. Participatory approaches promote collaborative approaches to enquiry and posit autistic people as active co-constructors of knowledge, a stance that is congruent with social work values of social justice and liberation. However, Covid-19 is not only altering our everyday life but also upending social research. This paper discusses the challenges faced by a participatory study involving autistic people during the Covid-19 pandemic. This paper examines how Covid-19 increased the individual vulnerability of autistic participants and changed their research priorities, increased the researcher’s decision-making power, and placed greater emphasis on barriers created by inaccessible methods. Covid-19 did not present novel challenges, but rather exacerbated existing tensions and inevitable challenges that are inherent in adopting an approach that aims to oppose oppression.

scholarly journals What Regional Living Conditions Affect Individual Smoking of Adults in Russia

2021 ◽  
Vol 66 ◽  
Author(s):  
Sergey A. Maksimov ◽  
Svetlana A. Shalnova ◽  
Yulia A. Balanova ◽  
Vladimir A. Kutsenko ◽  
Svetlana E. Evstifeeva ◽  
...  
Keyword(s):  
Mutual Influence ◽  
Adult Population ◽  
Principal Component ◽  
Estimating Equation ◽  
Individual Level ◽  
Composite Indices ◽  
Individual Probability ◽  
Wide Range ◽  
The Individual ◽  
The Impact

Objectives: Our study evaluated the impact of a wide range of characteristics of large administrative regions on the individual level of cigarette smoking in the Russian adult population.Methods: The pool of participants included 20,303 individuals aged 25–64 years. We applied 64 characteristics of the 12 Russian regions under study for 2010–2014. Using principal component analysis, we deduced five evidence-based composite indices of the regions. We applied the generalized estimating equation to determine associations between the regional indices and the individual level of smoking.Results: The increased Industrial index in the region is associated with the probability of smoking (odds ratio = 1.15; 95% confidence interval = 1.06–1.24). The other indices show associations with smoking only in separate gender and educational groups. Surprisingly, it was found that the Economic index has no associations with the probability of smoking.Conclusion: We evaluated the key associations of the territorial indices with the individual probability of smoking, as well as the mutual influence between the territorial indices and individual factors.

scholarly journals High human disturbance decreases individual variability in skink escape behavior

2019 ◽  
Vol 66 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Dana M Williams ◽  
Phat-Tan Nguyen ◽  
Kemal Chan ◽  
Madeleine Krohn ◽  
Daniel T Blumstein
Keyword(s):  
Human Disturbance ◽  
Model Comparison ◽  
Behavioral Plasticity ◽  
Escape Behavior ◽  
Antipredator Behavior ◽  
Individual Variability ◽  
Multiple Model ◽  
Individual Level ◽  
The Individual ◽  
The Impact

Abstract Animals living around people may modify their antipredator behavior as a function of proximity to humans, and this response has profound implications for whether or not a population can coexist with humans. We asked whether inland blue-tailed skinks Emoia impar modified their individual antipredator behavior as a function of differential exposure to humans. We conducted multiple consecutive flushes and recorded 2 measures of antipredator response: flight initiation distance (FID), the distance from a threatening stimulus at which an individual flees, and distance fled, the distance an individual fled after a flush. We used a multiple model comparison approach to quantify variation in individual escape behavior across multiple approaches and to test for differences in between-individual variation among populations. We found that individuals tolerated closer approach and fled shorter distances at locations with relatively less human disturbance than at locations with medium and high human disturbance, respectively. In addition, skinks living at high human disturbance sites had less variable FIDs than at low human disturbance sites. Two theories may explain these results. Selection against less favorable phenotypes has reduced behavioral variation in urban habitats and behavioral plasticity allows individuals to flexibly adjust their behavioral patterns in response to human disturbance. These results highlight the importance of studying variation within populations, at the individual level, which may better elucidate the impact that human disturbance has on the behavioral composition of populations.

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