| 1. |
- Sarneel, Judith M., et al.
(författare)
-
Reading tea leaves worldwide : decoupled drivers of initial litter decomposition mass-loss rate and stabilization
- 2024
-
Ingår i: Ecology Letters. - : John Wiley & Sons. - 1461-023X .- 1461-0248. ; 27:5
-
Tidskriftsartikel (refereegranskat)abstract
- The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.
|
|
| 2. |
- Björkman, Anne, 1981, et al.
(författare)
-
Plant functional trait change across a warming tundra biome
- 2018
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 562:7725, s. 57-62
-
Tidskriftsartikel (refereegranskat)abstract
- The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching because of global feedback effects between vegetation and climate. A better understanding of how environmental factors shape plant structure and function is crucial for predicting the consequences of environmental change for ecosystem functioning. Here we explore the biome-wide relationships between temperature, moisture and seven key plant functional traits both across space and over three decades of warming at 117 tundra locations. Spatial temperature–trait relationships were generally strong but soil moisture had a marked influence on the strength and direction of these relationships, highlighting the potentially important influence of changes in water availability on future trait shifts in tundra plant communities. Community height increased with warming across all sites over the past three decades, but other traits lagged far behind predicted rates of change. Our findings highlight the challenge of using space-for-time substitution to predict the functional consequences of future warming and suggest that functions that are tied closely to plant height will experience the most rapid change. They also reveal the strength with which environmental factors shape biotic communities at the coldest extremes of the planet and will help to improve projections of functional changes in tundra ecosystems with climate warming.
|
|
| 3. |
- Cornelissen, Johannes H C, et al.
(författare)
-
Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes
- 2007
-
Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 10:7, s. 619-627
-
Tidskriftsartikel (refereegranskat)abstract
- Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition. Here, we present the first quantitative analysis of the major climate-change-related drivers of litter decomposition rates in cold northern biomes worldwide.Leaf litters collected from the predominant species in 33 global change manipulation experiments in circum-arctic-alpine ecosystems were incubated simultaneously in two contrasting arctic life zones. We demonstrate that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species. Specifically, the ongoing warming-induced expansion of shrubs with recalcitrant leaf litter across cold biomes would constitute a negative feedback to global warming. Depending on the strength of other (previously reported) positive feedbacks of shrub expansion on soil carbon turnover, this may partly counteract direct warming enhancement of litter decomposition.
|
|
| 4. |
- Eklof, B., et al.
(författare)
-
The role of self-reported stressors in recovery from Exhaustion Disorder: a longitudinal study
- 2022
-
Ingår i: Bmc Psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 22
-
Tidskriftsartikel (refereegranskat)abstract
- Background Exhaustion disorder (ED) is a stress-induced disorder characterized by physical and mental symptoms of exhaustion that can be long-lasting. Although stress exposure is essential for the development of ED, little is known regarding the role of stressors in the maintenance of ED. The aim of the study was to investigate the role of work-related stressors, private-related stressors, and adverse childhood experiences in long-term recovery from ED. Methods A mixed methods design was used. The design was sequential, and data analysis was performed in two parts, where the first part consisted of qualitative analysis of patient records, and the second part consisted of statistical analysis of the data retrieved from the qualitative coding. Patient records from 150 patients with ED was analysed regarding work-related stressors, private-related stressors, and adverse childhood experiences. For each patient, two patient records were analysed, one from the time of diagnosis (baseline) and one from the follow-up clinical assessment, 7-12 years after diagnosis (follow-up). Out of the 150 patients, 51 individuals still fulfilled the diagnostic criteria for ED at follow-up (ED group) and 99 individuals no longer fulfilled the diagnostic criteria and were thus considered recovered (EDrec). Percentages in each group (ED and EDrec) reporting each stressor at baseline and follow-up were calculated as well as the differences in percentage points between the groups along with the 95% confidence intervals for the differences. Results At baseline, significantly more EDrec patients reported quantitative demands (73% EDrec, 53% ED) and managerial responsibilities (14% EDrec, 2% ED). Private-related stressors did not differ at baseline. At follow-up, significantly more ED patients reported managerial responsibilities (8 ED, 0% EDrec) and caregiver stress (child) (24% ED, 6% EDrec) and significantly more EDrec patients reported caregiver stress (parent) (6% EDrec, 0% ED). There were no differences regarding adverse childhood experiences. Conclusions The main conclusion is that neither adverse childhood experiences nor any of the stressors at baseline are associated with long-term ED. Ongoing stressors related to having responsibility for other people, such as managerial responsibilities or caring for a child with a chronic disease or psychiatric disorder, may be associated with long-term exhaustion.
|
|
| 5. |
- Gulin, S., et al.
(författare)
-
Is obsessive–compulsive personality disorder related to stress-related exhaustion?
- 2021
-
Ingår i: Brain and Behavior. - : Wiley. - 2162-3279. ; 11:6
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Recovery from stress-related diagnoses can, in some cases, be long-lasting, and several different factors could be related to such a lengthy recovery. One plausible aspect is obsessive–compulsive personality disorder (OCPD), which has previously been seen to be related to stress-related mental health. Thus, the aim of this study was to investigate whether recovery from exhaustion disorder (ED) is associated with OCPD. Methods: This study includes data from 147 patients (78% women, mean age 52.4±9.8years) who have been treated for ED. Clinical assessment was performed 7–10years after first seeking care identifying patients with residual exhaustion. Symptoms of OCPD were concomitantly measured and several aspects of work- and private-related stress exposure. Results: The main result of this study is that patients with residual clinical ED report OCPD to a greater extent, compared with patients who no longer fulfill the clinical criteria for ED, 7–10years after seeking care. Patients with OCPD that have not recovered report “excessive devotion to work” to a higher degree than patients with OCPD that have recovered. Conclusion: The results indicate that factors related to OCPD may be of clinical importance for the patient's recovery from ED. However, prospective studies should be conducted and studies elucidating whether symptoms of exhaustion among patients with OCPD can be affected by therapeutic interventions. © 2021 The Authors. Brain and Behavior published by Wiley Periodicals LLC
|
|
| 6. |
- Arvidsson, Elin, et al.
(författare)
-
Exercise training and physiological responses to acute stress: study protocol and methodological considerations of a randomised controlled trial
- 2018
-
Ingår i: BMJ Open Sport & Exercise Medicine. - : BMJ. - 2055-7647. ; 4:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: This paper describes the protocol and methodological prerequisites for a randomised controlled exercise intervention. Selected baseline data from the study are also presented, demonstrating some methodological challenges related to exercise intervention trials. The aim of the trial was to study the effects of exercise training on physiological responses to acute psychosocial stress in untrained individuals. Methods: Individuals with a low level of physical activity were invited to participate in an exercise intervention lasting for 6 months. A total of 119 participants were included and went through a peak oxygen uptake test and a psychosocial stress test at baseline. Adrenocorticotropic hormone (ACTH) and cortisol were measured in connection to the stress test to identify the physiological response. Results: Almost 90% of the participants reported themselves as untrained, but results from the objectively measured oxygen uptake did not seem to correspond to the reported sedentary lifestyle. The primary outcome measures at baseline varied between individuals. The mean change from pre-test to peak value was 214% for ACTH and 94% for cortisol. Of these, 13 individuals did not respond in ACTH and/or and cortisol. Discussion: Supposedly untrained individuals seeking participation in an exercise intervention might not be as untrained as they report, a methodological consideration of importance when evaluating the effects of training. Another important consideration is related to the primary outcome measure, which should be measurable and possible to affect. Absence of reaction at baseline means that changes can only be detected as an increased reaction.
|
|
| 7. |
|
|
| 8. |
- Callaghan, Terry V., et al.
(författare)
-
Responses to projected changes in climate and UV-B at the species level
- 2004
-
Ingår i: Ambio: a Journal of Human Environment. - : Royal Swedish Academy of Sciences. - 0044-7447. ; 33:7, s. 418-435
-
Forskningsöversikt (refereegranskat)abstract
- Environmental manipulation experiments showed that species respond individualistically to each environmental-change variable. The greatest responses of plants were generally to nutrient, particularly nitrogen, addition. Summer warming experiments showed that woody plant responses were dominant and that mosses and lichens became less abundant. Responses to warming were controlled by moisture availability and snow cover. Many invertebrates increased population growth in response to summer warming, as long as desiccation was not induced. CO2 and UV-B enrichment experiments showed that plant and animal responses were small. However, some microorganisms and species of fungi were sensitive to increased UV-B and some intensive mutagenic actions could, perhaps, lead to unexpected epidemic outbreaks. Tundra soil heating, CO 2 enrichment and amendment with mineral nutrients generally accelerated microbial activity. Algae are likely to dominate cyanobacteria in milder climates. Expected increases in winter freeze-thaw cycles leading to ice-crust formation are likely to severely reduce winter survival rate and disrupt the population dynamics of many terrestrial animals. A deeper snow cover is likely to restrict access to winter pastures by reindeer/caribou and their ability to flee from predators while any earlier onset of the snow-free period is likely to stimulate increased plant growth. Initial species responses to climate change might occur at the sub-species level: an Arctic plant or animal species with high genetic/racial diversity has proved an ability to adapt to different environmental conditions in the past and is likely to do so also in the future. Indigenous knowledge, air photographs, satellite images and monitoring show that changes in the distributions of some species are already occurring: Arctic vegetation is becoming more shrubby and more productive, there have been recent changes in the ranges of caribou, and "new" species of insects and birds previously associated with areas south of the treeline have been recorded. In contrast, almost all Arctic breeding bird species are declining and models predict further quite dramatic reductions of the populations of tundra birds due to warming. Species-climate response surface models predict potential future ranges of current Arctic species that are often markedly reduced and displaced northwards in response to warming. In contrast, invertebrates and microorganisms are very likely to quickly expand their ranges northwards into the Arctic.
|
|
| 9. |
- Carlsson, S, et al.
(författare)
-
Evidence for an adrenergic innervation of the adrenal cortical blood vessels in rats.
- 1993
-
Ingår i: Acta physiologica Scandinavica. - 0001-6772. ; 149:1, s. 23-30
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the blood flow in the adrenal cortex of the rat. Relative changes in the adrenal cortical blood flow were continuously measured by Laser Doppler flowmetry in 33 chloralose-anaesthetized artificially ventilated rats during electrical stimulation (1 ms, 5 V) of the left great splanchnic nerve (LGSN), which conveys both pre- and post-ganglionic nerve fibres to the adrenal gland. Laser Doppler flux (LDF) was decreased and regional resistance (RR) was increased by augmenting nerve stimulation at increasingly higher frequencies (2, 4, 8, 20 and 40 Hz). The decrease in LDF, when compared to pre-drug stimulations at 4 Hz was partially or totally inhibited by the adrenergic blocking agents trimethaphan (TRIM), guanethidine (GUA) and alpha 1-blockade with prazosin (PRAZ). Furthermore, both the decrease in LDF and the increase in RR were either completely or partially blocked by stimulation at 40 Hz after TRIM-treatment and GUA-treatment. It is concluded that the adrenal cortex in the rat is innervated by post-ganglionic adrenergic nerve fibres, which are involved in the regulation of blood flow in the adrenal cortex.
|
|
| 10. |
- Ellbin, S., et al.
(författare)
-
Self-reported cognitive impairment and daily life functioning 7-12 years after seeking care for stress-related exhaustion
- 2021
-
Ingår i: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 62:4, s. 484-492
-
Tidskriftsartikel (refereegranskat)abstract
- The overall aim of this study was to investigate self-reported cognitive difficulties, daily life activities, and health/sleep factors in former patients with exhaustion disorder (ED) who still fulfill the clinical criteria for exhaustion 7-12 years after seeking care. The Sahlgrenska Self-reported Cognitive Impairment Questionnaire (SASCI-Q) was used to measure cognitive difficulties, daily life activities, and health/sleep factors. Three groups were compared: previous patients still judged to be clinically exhausted seven years or more after seeking care (n = 51); previous patients considered clinically recovered (n = 98); and healthy controls (n = 50). Patients who still fulfilled the diagnostic criteria for ED reported widespread problems related to cognition, fatigue, and daily life functioning compared to the clinically recovered group. Furthermore, despite no longer fulfilling the clinical criteria, the recovered patients still reported more problems related to cognitive functioning and fatigue compared to healthy controls. Thus, this group appeared intermediary between the non-recovered group and healthy controls regarding self-reported cognitive functioning. To conclude, ED may have considerable negative long-term effects, and it is possible that some of these residual symptoms, particularly the cognitive problems and persistent fatigue, are permanent in some patients. Preventive measures should be the primary focus for all stakeholders, since the consequences of stress-related mental health problems seem to be extensive and long-lasting.
|
|
