| 1. |
- Beckwée, David, et al.
(författare)
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Exercise therapy for knee osteoarthritis pain: how does it work? A study protocol for a randomised controlled trial
- 2024
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Ingår i: BMJ open. - 2044-6055. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Muscle strengthening training (MST) and behavioural graded activity (BGA) show comparable effects on knee osteoarthritic (KOA) pain, but the mechanisms of action remain unclear. Both exercise-induced anti-inflammation and central sensitisation are promising pathways for pain relief in response to exercise therapy in patients with KOA: MST has the potential to decrease inflammation and BGA has the potential to decrease central sensitisation. Hence, this study aims to examine inflammation and central sensitisation as mediators for the effect of MST and/or BGA on pain in patients with KOA. METHODS AND ANALYSIS: The Knee OsteoArthritis PAIN trial started on 10 January 2020 (anticipated end: April 2024). The three-arm clinical trial aims to recruit 90 KOA patients who will be randomly allocated to 12 weeks of (1) MST, (2) BGA or (3) care as usual. Assessments will be performed at baseline, 13 and 52 weeks after finishing the intervention. Outcomes, including pain (Knee injury and Osteoarthritis Outcome Score), were chosen in line with the OARSI recommendations for clinical trials of rehabilitation interventions for OA and the IMMPACT/OMERACT recommendations for the assessment of physical function in chronic pain clinical trials. Inflammation as well as features of central sensitisation (including conditioned pain modulation, offset analgesia, temporal summation of pain and event-related potentials following electrical stimulation), will be considered as treatment mediators. A multiple mediators model will be estimated with a path-analysis using structural equation models. In July 2023, all 90 KOA patients have been included and 42 participants already finished the study. ETHICS AND DISSEMINATION: This study obtained ethics approval (B.U.N. 143201941843). Unravelling the mechanisms of action of exercise therapy in KOA will not only be extremely valuable for researchers, but also for exercise immunology and pain scientists and clinicians. TRIAL REGISTRATION NUMBER: NCT04362618.
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| 2. |
- Elberling, Bo, et al.
(författare)
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High Arctic soil CO2 and CH4 production controlled by temperature, water, freezing and snow
- 2008
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Ingår i: High-arctic ecosystem dynamics in a changing climate - Ten years of monitoring and research at Zackenberg Research Station, Northeast Greenland (Advances in Ecological Research). - 0065-2504. - 9780123736659 ; 40, s. 441-472
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Soil gas production processes, mainly anaerobic or aerobic soil respiration, drive major gas fluxes across the soil-atmosphere interface. Carbon dioxide (CO2) effluxes, an efflux which in most ecosystems is a result of both autotrophic and heterotrophic respiration, in particular have received international attention. The importance of both CO2 and methane (CH4) fluxes are emphasised in the Arctic because of the large amount of soil organic carbon stored in terrestrial ecosystems and changes in uptake and release due to climate changes. This chapter focuses on controls on spatial and temporal trends in subsurface CO2 and CH4 production as well as on transport and release of gases from the soil observed in the valley Zackenbergdalen. A dominance of near-surface temperatures controlling both spatial and seasonal trends is shown based on data obtained using closed chamber and eddy-correlation techniques as well as in manipulated field plots and in controlled incubation experiments. Despite variable temperature sensitivities reported, most data can be fairly well fitted to exponential temperature-dependent equations. The water content (at wet sites linked to the depth to the water table) is a second major factor regulating soil respiration processes, but the effect is quite different in contrasting vegetation types. Dry heath sites are shown to be periodically water limited during the growing season and respond therefore with high respiration rates when watered. In contrast, water saturated conditions during most of the growing season in the fen areas hinder the availability of oxygen, resulting in both CO2 and CH4 production. Thus, water table drawdown results in decreasing CH4 effluxes but increasing CO2 effluxes. Additional controls on gas production are shown to be related to the availability of substrate and plant productivity. Subsurface gas production will produce partial and total pressure gradient causing gas transport, which in well-drained soils is mainly controlled by diffusion, whereas gas advection, bubbles and transport through roots and stems may be important in more saturated soils. Bursts of CO2 gas have been observed during spring thaw and confirmed in controlled soil thawing experiments. Field observations as well as experimental work suggest that such bursts represent partly on-going soil respiration and a physical release of gas produced during the winter. The importance of winter soil respiration is emphasised because of the fact that microbial respiration in Zackenberg samples is noted down to a least -18 degrees C. Hence, the importance of winter respiration and burst events in relation to seasonal and future climate trends requires more than just summer measurements. For example, the autumn period seems important as snowfall prior to low air temperature may insulate the soil, keeping soil temperatures high. This will extend the period of high soil respiration rates and thereby increase the importance of the winter period for the annual carbon balance. Because of the complexity of factors controlling subsurface gas production, we conclude that different parts of the landscape will respond quite differently to the same climate changes as well as that short-term effects are likely to be different from long-term effects.
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| 3. |
- Graae, Bente J, et al.
(författare)
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On the use of weather data in ecological studies along altitudinal and latitudinal gradients
- 2012
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 121:1, s. 3-19
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Tidskriftsartikel (refereegranskat)abstract
- Global warming has created a need for studies along climatic gradients to assess the effects of temperature on ecological processes. Altitudinal and latitudinal gradients are often used as such, usually in combination with air temperature data from the closest weather station recorded at 1.52 m above the ground. However, many ecological processes occur in, at, or right above the soil surface. To evaluate how representative the commonly used weather station data are for the microclimate relevant for soil surface biota, we compared weather station temperatures for an altitudinal (500900 m a.s.l.) and a latitudinal gradient (4968 degrees N) with data obtained by temperature sensors placed right below the soil surface at five sites along these gradients. The mean annual temperatures obtained from weather stations and adjusted using a lapse rate of -5.5 degrees C km-1 were between 3.8 degrees C lower and 1.6 degrees C higher than those recorded by the temperature sensors at the soil surface, depending on the position along the gradients. The monthly mean temperatures were up to 10 degrees C warmer or 5 degrees C colder at the soil surface. The within-site variation in accumulated temperature was as high as would be expected from a 300 m change in altitude or from a 4 degrees change in latitude or a climate change scenario corresponding to warming of 1.63.8 degrees C. Thus, these differences introduced by the decoupling are significant from a climate change perspective, and the results demonstrate the need for incorporating microclimatic variation when conducting studies along altitudinal or latitudinal gradients. We emphasize the need for using relevant temperature data in climate impact studies and further call for more studies describing the soil surface microclimate, which is crucial for much of the biota.
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| 4. |
- Haesen, Stef, et al.
(författare)
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ForestClim : Bioclimatic variables for microclimate temperatures of European forests
- 2023
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 29:11, s. 2886-2892
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Tidskriftsartikel (refereegranskat)abstract
- Microclimate research gained renewed interest over the last decade and its importance for many ecological processes is increasingly being recognized. Consequently, the call for high-resolution microclimatic temperature grids across broad spatial extents is becoming more pressing to improve ecological models. Here, we provide a new set of open-access bioclimatic variables for microclimate temperatures of European forests at 25 x 25 m2 resolution.
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| 5. |
- Hostens, Lore, et al.
(författare)
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The drivers of dark diversity in the Scandinavian mountains are metric-dependent
- 2023
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Ingår i: Journal of Vegetation Science. - : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 34:6
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Tidskriftsartikel (refereegranskat)abstract
- Question: Dark diversity refers to the set of species that are not observed in an area but could potentially occur based on suitable local environmental conditions. In this paper, we applied both niche-based and co-occurrence-based methods to estimate the dark diversity of vascular plant species in the subarctic mountains. We then aimed to unravel the drivers explaining (a) why some locations were missing relatively more suitable species than others, and (b) why certain plant species were more often absent from suitable locations than others.Location: The Scandinavian mountains around Abisko, northern Sweden.Methods: We calculated the dark diversity in 107 plots spread out across four mountain trails using four different methods: two co-occurrence-based (Beals’ index and the hypergeometric method) and two niche-based (the climatic niche model and climatic niche model followed by species-specific threshold). We then applied multiple Generalized Linear Mixed-Effects Models and General Linear Models to determine which habitat characteristics and species traits contributed the most to dark diversity.Results: The study showed a notable divergence in the predicted drivers of dark diversity depending on the method used. Nevertheless, we can conclude that plot-level dark diversity was generally 17% higher in areas at low elevations and 31% higher in areas with a low species richness.Conclusion: Our findings call for caution when interpreting statistical findings of dark-diversity estimates. Even so, all analyses point toward an important role for natural processes such as competitive dominance as the main driver of the spatial patterns found in dark diversity in the northern Scandes.
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| 6. |
- Kemppinen, Julia, et al.
(författare)
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Microclimate, an important part of ecology and biogeography
- 2024
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Ingår i: GLOBAL ECOLOGY AND BIOGEOGRAPHY. - 1466-822X .- 1466-8238. ; 33:6
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Tidskriftsartikel (refereegranskat)abstract
- Brief introduction: What are microclimates and why are they important?Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography in terrestrial ecosystems, and where this field is heading next.Microclimate investigations in ecology and biogeographyWe highlight the latest research on interactions between microclimates and organisms, including how microclimates influence individuals, and through them populations, communities and entire ecosystems and their processes. We also briefly discuss recent research on how organisms shape microclimates from the tropics to the poles.Microclimate applications in ecosystem managementMicroclimates are also important in ecosystem management under climate change. We showcase new research in microclimate management with examples from biodiversity conservation, forestry and urban ecology. We discuss the importance of microrefugia in conservation and how to promote microclimate heterogeneity.Methods for microclimate scienceWe showcase the recent advances in data acquisition, such as novel field sensors and remote sensing methods. We discuss microclimate modelling, mapping and data processing, including accessibility of modelling tools, advantages of mechanistic and statistical modelling and solutions for computational challenges that have pushed the state-of-the-art of the field.What's next?We identify major knowledge gaps that need to be filled for further advancing microclimate investigations, applications and methods. These gaps include spatiotemporal scaling of microclimate data, mismatches between macroclimate and microclimate in predicting responses of organisms to climate change, and the need for more evidence on the outcomes of microclimate management.
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| 7. |
- Lembrechts, Jonas J., et al.
(författare)
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Alien Roadside Species More Easily Invade Alpine than Lowland Plant Communities in a Subarctic Mountain Ecosystem
- 2014
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Ingår i: PLOS ONE. - San Francisco : Public Library of Science. - 1932-6203. ; 9:2, s. e89664-
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Tidskriftsartikel (refereegranskat)abstract
- Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment.
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| 8. |
- Lembrechts, Jonas J., et al.
(författare)
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Comparing temperature data sources for use in species distribution models : From in-situ logging to remote sensing
- 2019
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 28:11, s. 1578-1596
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Tidskriftsartikel (refereegranskat)abstract
- Aim Although species distribution models (SDMs) traditionally link species occurrences to free-air temperature data at coarse spatio-temporal resolution, the distribution of organisms might instead be driven by temperatures more proximal to their habitats. Several solutions are currently available, such as downscaled or interpolated coarse-grained free-air temperatures, satellite-measured land surface temperatures (LST) or in-situ-measured soil temperatures. A comprehensive comparison of temperature data sources and their performance in SDMs is, however, currently lacking. Location Northern Scandinavia. Time period 1970-2017. Major taxa studied Higher plants. Methods We evaluated different sources of temperature data (WorldClim, CHELSA, MODIS, E-OBS, topoclimate and soil temperature from miniature data loggers), differing in spatial resolution (from 1 '' to 0.1 degrees), measurement focus (free-air, ground-surface or soil temperature) and temporal extent (year-long versus long-term averages), and used them to fit SDMs for 50 plant species with different growth forms in a high-latitudinal mountain region. Results Differences between these temperature data sources originating from measurement focus and temporal extent overshadow the effects of temporal climatic differences and spatio-temporal resolution, with elevational lapse rates ranging from -0.6 degrees C per 100 m for long-term free-air temperature data to -0.2 degrees C per 100 m for in-situ soil temperatures. Most importantly, we found that the performance of the temperature data in SDMs depended on the growth forms of species. The use of in-situ soil temperatures improved the explanatory power of our SDMs (R-2 on average +16%), especially for forbs and graminoids (R-2 +24 and +21% on average, respectively) compared with the other data sources. Main conclusions We suggest that future studies using SDMs should use the temperature dataset that best reflects the ecology of the species, rather than automatically using coarse-grained data from WorldClim or CHELSA.
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| 9. |
- Lembrechts, Jonas J., et al.
(författare)
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Global maps of soil temperature
- 2022
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 28:9, s. 3110-3144
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Tidskriftsartikel (refereegranskat)abstract
- Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean=3.0±2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6±2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7±2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.
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| 10. |
- Lembrechts, Jonas J., et al.
(författare)
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Mountain roads shift native and non-native plant species' ranges
- 2017
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Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 40:3, s. 353-364
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Tidskriftsartikel (refereegranskat)abstract
- Roads are known to act as corridors for dispersal of plant species. With their variable microclimate, role as corridors for species movement and reoccurring disturbance events, they show several characteristics that might influence range dynamics of both native and non-native species. Previous research on plant species ranges in mountains however seldom included the effects of roads. To study how ranges of native and non-native species differ between roads and adjacent vegetation, we used a global dataset of plant species composition along mountain roads. We compared average elevation and range width of species, and used generalized linear mixed models (GLMMs) to compile their range optimum and amplitude. We then explored differences between roadside and adjacent plots based on a species' origin (native vs non-native) and nitrogen and temperature affinity. Most non-native species had on average higher elevational ranges and broader amplitudes in roadsides. Higher optima for non-native species were associated with high nitrogen and temperature affinity. While lowland native species showed patterns comparable to those in non-native species, highland native species had significantly lower elevational ranges in roadsides compared to the adjacent vegetation. We conclude that roadsides indeed change the elevational ranges of a variety of species. These changes are not limited to the expansion of non-native species along mountain roads, but also include both upward and downward changes in ranges of native species. Roadsides may thus facilitate upward range shifts, for instance related to climate change, and they could serve as corridors to facilitate migration of alpine species between adjacent high-elevation areas. We recommend including the effects of mountain roads in species distribution models to fine-tune the predictions of range changes in a warming climate.
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| 11. |
- Lembrechts, Jonas J., et al.
(författare)
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SoilTemp : A global database of near-surface temperature
- 2020
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 26:11, s. 6616-6629
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Tidskriftsartikel (refereegranskat)abstract
- Current analyses and predictions of spatially explicit patterns and processes in ecology most often rely on climate data interpolated from standardized weather stations. This interpolated climate data represents long-term average thermal conditions at coarse spatial resolutions only. Hence, many climate-forcing factors that operate at fine spatiotemporal resolutions are overlooked. This is particularly important in relation to effects of observation height (e.g. vegetation, snow and soil characteristics) and in habitats varying in their exposure to radiation, moisture and wind (e.g. topography, radiative forcing or cold-air pooling). Since organisms living close to the ground relate more strongly to these microclimatic conditions than to free-air temperatures, microclimatic ground and near-surface data are needed to provide realistic forecasts of the fate of such organisms under anthropogenic climate change, as well as of the functioning of the ecosystems they live in. To fill this critical gap, we highlight a call for temperature time series submissions to SoilTemp, a geospatial database initiative compiling soil and near-surface temperature data from all over the world. Currently, this database contains time series from 7,538 temperature sensors from 51 countries across all key biomes. The database will pave the way toward an improved global understanding of microclimate and bridge the gap between the available climate data and the climate at fine spatiotemporal resolutions relevant to most organisms and ecosystem processes.
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| 12. |
- Lembrechts, Jonas J., et al.
(författare)
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Trade-off between competition and facilitation defines gap colonization in mountains
- 2015
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Ingår i: AoB Plants. - : Oxford University Press (OUP). - 2041-2851. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Recent experimental observations show that gap colonization in small-stature (e.g. grassland and dwarf shrubs) vegetation strongly depends on the abiotic conditions within them. At the same time, within-gap variation in biotic interactions such as competition and facilitation, caused by distance to the gap edge, would affect colonizer performance, but a theoretical framework to explore such patterns is missing. Here, we model how competition, facilitation and environmental conditions together determine the small-scale patterns of gap colonization along a cold gradient in mountains, by simulating colonizer survival in gaps of various sizes. Our model adds another dimension to the known effects of biotic interactions along a stress gradient by focussing on the trade-off between competition and facilitation in the within-gap environment. We show that this trade-off defines a peak in colonizer survival at a specific distance from the gap edge, which progressively shifts closer to the edge as the environment gets colder, ultimately leaving a large fraction of gaps unsuitable for colonization in facilitation-dominated systems. This is reinforced when vegetation size and temperature amelioration are manipulated simultaneously with temperature in order to simulate an elevational gradient more realistically. Interestingly, all other conditions being equal, the magnitude of the realized survival peak was always lower in large than in small gaps, making large gaps harder to colonize. The model is relevant to predict effects of non-native plant invasions and climate warming on colonization processes in mountains.
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| 13. |
- Milbau, Ann, et al.
(författare)
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A hierarchical framework for integrating invasibility experiments incorporating different factors and spatial scales
- 2009
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Ingår i: Biological Invasions. - : Springer Netherlands. - 1387-3547 .- 1573-1464. ; 11:4, s. 941-950
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Tidskriftsartikel (refereegranskat)abstract
- Results from experiments studying different factors determining invasibility (e.g. land use, disturbance, biotic interactions) at different spatial scales are mainly used in isolation, probably because a methodology for integration is lacking. Recent studies show that factors affecting invasibility most likely do so in a hierarchical manner, with different factors acting more strongly at different spatial scales. Climate can be considered the dominant factor at the continental scale, while at regional and landscape scale topography, land cover and land use become increasingly important. At smaller spatial scales, soil type, disturbance, biotic interactions, resources, and microclimate may become significant. In the current paper, we propose a hierarchical framework for combining results from different types of studies. In this hierarchical system, factors operating at a smaller scale are subordinate to factors operating at a larger scale, but if conditions at higher levels are satisfied, the small-scale factors may become indispensable for making accurate predictions. Depending on the aim of the study, the accuracy of prediction can be selected by the researcher, which in its turn determines which data are required.We discuss several applications of the framework and indicate some options for future research. Although the complexity of natural systems presents fundamental limits to predictions, we think this framework can provide a useful tool for the identification of areas of risk for biological invasions, for improving our understanding of invasibility, and for identifying gaps in our current knowledge.
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| 14. |
- Milbau, Ann, et al.
(författare)
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Effects of a warmer climate on seed germination in the Subarctic
- 2009
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Ingår i: Annals of Botany. - : Oxford University Press. - 0305-7364 .- 1095-8290. ; 104, s. 287-296
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims In a future warmer subarctic climate, the soil temperatures experienced by dispersed seeds are likely to increase during summer but may decrease during winter due to expected changes in snow depth, duration and quality. Because little is known about the dormancy-breaking and germination requirements of subarctic species, how warming may influence the timing and level of germination in these species was examined. Methods Under controlled conditions, how colder winter and warmer summer soil temperatures influenced germination was tested in 23 subarctic species. The cold stratification and warm incubation temperatures were derived from real soil temperature measurements in subarctic tundra and the temperatures were gradually changed over time to simulate different months of the year. Key Results Moderate summer warming (+ 2.5 °C) substantially accelerated germination in all but four species but did not affect germination percentages. Optimum germination temperatures (20/10 °C) further decreased germination time and increased germination percentages in three species. Colder winter soil temperatures delayed the germination in ten species and decreased the germination percentage in four species, whereas the opposite was found in Silene acaulis. In most species, the combined effect of a reduced snow cover and summer warming resulted in earlier germination and thus a longer first growing season, which improves the chance of seedling survival. In particular the recruitment of (dwarf ) shrubs (Vaccinium myrtillus, V. vitis-idaea, Betula nana), trees (Alnus incana, Betula pubescens) and grasses (Calamagrostis lapponica, C. purpurea) is likely to benefit from a warmer subarctic climate. Conclusions Seedling establishment is expected to improve in a future warmer subarctic climate, mainly by considerably earlier germination. The magnitudes of the responses are species-specific, which should be taken into account when modelling population growth and migration of subarctic species.
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| 15. |
- Puts, Sofie, et al.
(författare)
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Exercise-induced effects on inflammatory markers and brain-derived neurotrophic factor in patients with knee osteoarthritis. A systematic review with meta-analysis
- 2023
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Ingår i: Exercise immunology review. - 1077-5552. ; 29, s. 22-53
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Tidskriftsartikel (refereegranskat)abstract
- Background: In the pathogenesis of knee osteoarthritis (KOA), inflammatory mediators play an important role. However, the precise underlying mechanism by which regular exercise therapy (ET) exert effects on the immune system in KOA patients is unknown. Objectives: The aim of this systematic review was to investigate the basal and acute effects of ET on inflammatory biomarkers and brain derived neurotrophic factor (BDNF) in KOA patients. Methods: PubMed, Web Of Science and PEDro were systematically searched for appropriate studies. If possible, a meta-analysis was performed or an approximation of the effect size (ES) was calculated. Risk of bias was scored using the Cochrane ROB 2.0 or ROBINS-tools. Results: Twenty-one studies involving 1374 participants were included. Fifteen articles focused on basal exercise effects, four on acute effects, and two on both. Biomarker analysis (n=18) was performed in synovial fluid (n=4) or serum/plasma (n=17). A meta-analysis demonstrated that basal CRP was reduced in KOA patients 6-18 weeks weeks after ET (MD: -0.17;95%CI[-0.31;-0.03]), while IL-6 (MD: 0.21;95%CI[-0.44;0.85]), and TNF-α (MD: -0.57;95%CI[-1.47;0.32]), levels did not significantly change. Also, sTNFR1/2 did not change significantly after ET. For other biomarkers, insufficient data were available to perform a meta-analysis. Nevertheless, a low degree of evidence was found for a decrease in IL-6 (ES:-0.596 & -0.259 & -0.513), an increase in sTNFR1 (ES:2.325), a decrease in sTNFR2 (ES:-0.997) and an increase in BDNF (ES:1.412). Locally, intra-articular IL-10 (ES:9.163) increased, and IL1β (ES:-6.199) and TNF-α decreased (ES:-2.322) after ET. An acute exercise session elicited a myokine response (ES IL-6:0.314), and an increase in BDNF (no ES-data). No inflammatory effect (ES CRP:0.052; ES TNF-α:-0.019 & 0.081) following an acute bout of training was found. However, a single bout of exercise elicited a decrease in intra-articular IL-10 (no ES-data). Conclusion: ET can induce circulatory and intra-articular anti-inflammatory effects in patients with KOA. The antiinflammatory properties have important implications for informing these patients and clinicians about the underlying effects of ET.
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| 16. |
- Shevtsova, Anna, et al.
(författare)
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Critical periods for impact of climate-warming on early seedling establishment in subarctic tundra
- 2010
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 15:11, s. 2662-2680
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming is expected to shift bioclimatic zones and plant species distribution. Yet, few studies have explored whether seedling establishment is a possible bottleneck for future migration and population resilience. We test how warming affects the early stages of seedling establishment in 10 plant species in subarctic tundra. To zoom into the life phases where the effects of warming actually take place, we used a novel approach of breaking down the whole-season warming effect into full factorial combination of early-, mid-, and late-season warming periods. Seeds were sown in containers placed under field conditions in subarctic heath and were exposed to 3 °C elevation of surface temperature and 30% addition of summer precipitation relative to ambient. Heating was achieved with Free Air Temperature Increase systems. Whole-season heating reduced germination and establishment, significantly in four out of 10 species. The whole-season warming effect originated from additive effects of individual periods, although some of the periods had disproportionally stronger influence. Early-germinating species were susceptible to warming; the critical phases were early summer for germination and mid summer for seedling survival. Graminoids, which emerged later, were less susceptible although some negative effects during late summer were observed. Some species with intermediate germination time were affected by all periods of warming. Addition of water generally could not mitigate the negative effects of whole-season heating, but at individual species level both strengthening and amelioration of these negative effects were observed. We conclude that summer warming is likely to constrain seedling recruitment in open micro sites, which is a common seed regeneration niche in tundra ecosystem. Importantly, we described both significant temporal and species-specific variation in the sensitivity of seedling establishment to warming which needs to be taken into consideration when modelling population dynamics and vegetation transitions in a warmer climate.
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| 17. |
- Wiegmans, Dymphna, et al.
(författare)
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Historic disturbance events overruled climatic factors as drivers of ruderal species distributions in the Scandinavian mountains
- 2024
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Ingår i: Nordic Journal of Botany. - : John Wiley & Sons. - 0107-055X .- 1756-1051.
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Tidskriftsartikel (refereegranskat)abstract
- The contemporary interaction of climate and disturbance drives vegetation composition and species distribution shifts, making their respective roles difficult to disentangle. This study describes the long-term ruderal plant species distributions along the ‘Rallarvägen' in Abisko, subarctic Sweden. This trail currently serves as a hiking trail but was initially created as a construction road for a railroad from 1898 to 1903 and is paralleled by the E10 Highway since 1982. Using vegetation and climate data from 1903, 1913, 1983, and 2021, we found that warm-adapted ruderal plant species were common along the Rallarvägen shortly after railroad construction in the early 20th century. Interestingly, many of these native and non-native ruderals with relatively high temperature affinity that were present in 1903 and 1913 have since disappeared and have not reappeared, despite the substantial increase in regional temperature in recent decades. In addition, the historical disturbances have had long-lasting effects on the current spatial distribution of the ruderal vegetation. Most ruderals still reside close to the railroad tracks and are progressively filtered out with increasing distance from anthropogenically disturbed introductory points, such as train stations, where they peak in species richness – a process we term ‘horizontal directional ecological filtering', in parallel to the established concept of ‘directional ecological filtering' along elevational gradients. The historical record of ruderal plant species in the region, influenced by a century-old railroad construction, emphasizes the importance of knowing a system's disturbance history for understanding current vegetation dynamics and anticipating its future in a changing climate.
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| 18. |
- Zhang, Helin, et al.
(författare)
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Complex nonmonotonic responses of biodiversity to habitat destruction
- 2023
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Ingår i: Ecology. - : WILEY. - 0012-9658 .- 1939-9170.
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Tidskriftsartikel (refereegranskat)abstract
- It has typically been assumed that habitat destruction, characterized by habitat loss and fragmentation, has consistently negative effects on biodiversity. While numerous empirical studies have shown the detrimental effects of habitat loss, debate continues as to whether habitat fragmentation has universally negative effects. To explore the effects of habitat fragmentation, we developed a simple model for site-occupancy dynamics in fragmented landscapes. With the model, we demonstrate that a competition-colonization trade-off can result in nonlinear oscillatory responses in biodiversity to both habitat loss and fragmentation. However, the overall pattern of habitat loss reducing species richness is still established, in line with empirical observations. Interestingly, the existence of localized oscillations in biodiversity can explain the mixed responses of species richness to habitat fragmentation per se observed in nature, thereby reconciling the debate on the fragmentation-diversity relationship. Therefore, this study offers a parsimonious mechanistic explanation for empirically observed biodiversity patterns in response to habitat destruction.
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| 19. |
- Zhang, Helin, et al.
(författare)
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Dispersal network heterogeneity promotes species coexistence in hierarchical competitive communities
- 2021
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Ingår i: Ecology Letters. - : WILEY. - 1461-023X .- 1461-0248. ; 24:1, s. 50-59
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the mechanisms of biodiversity maintenance is a fundamental issue in ecology. The possibility that species disperse within the landscape along differing paths presents a relatively unexplored mechanism by which diversity could emerge. By embedding a classical metapopulation model within a network framework, we explore how access to different dispersal networks can promote species coexistence. While it is clear that species with the same demography cannot coexist stably on shared dispersal networks, we find that coexistence is possible on unshared networks, as species can surprisingly form self-organised clusters of occupied patches with the most connected patches at the core. Furthermore, a unimodal biodiversity response to an increase in species colonisation rates or average patch connectivity emerges in unshared networks. Increasing network size also increases species richness monotonically, producing characteristic species-area curves. This suggests that, in contrast to previous predictions, many more species can co-occur than the number of limiting resources.
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