| 1. |
- Cornelissen, Johannes H C, et al.
(författare)
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Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes
- 2007
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 10:7, s. 619-627
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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.
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| 2. |
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| 3. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
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Rebound effects of energy efficiency measures in the transport sector in Sweden
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rebound effects represent the difference between anticipated or projected energy savings and the real energy saving in relation to, for example, implemented policy measures aimed at improving energy efficiency. Rebound effects in the transport sector may counteract policy measures so that goals related to energy or emissions are not achieved, or achievement is greatly delayed. This comprehensive report examines the presence of rebound effects within the transport sector and while the aim was to provide a full review of the issue, for some transport areas it was not possible to find any studies on rebound effects. Those areas are identified as having knowledge gaps. We summarize the literature for rebound effects for passenger vehicles, technological developments, freight transports, public lighting, aviation, waterborne transports and for indirect, economy-wide effects, and also discuss rebound effects in aspects of environmental awareness and in the transport and community planning. The existing literature suggests that rebound effects exist to varying degrees and that there is a high risk of energy efficiency measures transferring transport energy savings into other transport modes, sectors or energy services. Consequently, rebound effects should be included when calculating whether Sweden will reach its climate and energy goals.
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| 4. |
- Alatalo, J. M., et al.
(författare)
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Bryophyte cover and richness decline after 18 years of experimental warming in alpine Sweden
- 2020
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Ingår i: Aob Plants. - Oxford : Oxford University Press (OUP). - 2041-2851. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is expected to affect alpine and Arctic tundra communities. Most previous long-term studies have focused on impacts on vascular plants, this study examined impacts of long-term warming on bryophyte communities. Experimental warming with open-top chambers (OTCs) was applied for 18 years to a mesic meadow and a dry heath alpine plant community. Species abundance was measured in 1995, 1999, 2001 and 2013. Species composition changed significantly from original communities in the heath, but remained similar in mesic meadow. Experimental warming increased beta diversity in the heath. Bryophyte cover and species richness both declined with long-term warming, while Simpson diversity showed no significant responses. Over the 18-year period, bryophyte cover in warmed plots decreased from 43 % to 11 % in heath and from 68 % to 35 % in meadow (75 % and 48 % decline, respectively, in original cover), while richness declined by 39 % and 26 %, respectively. Importantly, the decline in cover and richness first emerged after 7 years. Warming caused significant increase in litter in both plant communities. Deciduous shrub and litter cover had negative impact on bryophyte cover. We show that bryophyte species do not respond similarly to climate change. Total bryophyte cover declined in both heath and mesic meadow under experimental long-term warming (by 1.5-3 degrees C), driven by general declines in many species. Principal response curve, cover and richness results suggested that bryophytes in alpine heath are more susceptible to warming than in meadow, supporting the suggestion that bryophytes may be less resistant in drier environments than in wetter habitats. Species loss was slower than the decline in bryophyte abundance, and diversity remained similar in both communities. Increased deciduous shrub and litter cover led to decline in bryophyte cover. The non-linear response to warming over time underlines the importance of long-term experiments and monitoring.
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| 5. |
- Alatalo, Juha M., et al.
(författare)
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Climate change and climatic events: community-, functional- and species-level responses of bryophytes and lichens to constant, stepwise, and pulse experimental warming in an alpine tundra
- 2014
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Ingår i: Alpine Botany. - : Springer Science and Business Media LLC. - 1664-2201 .- 1664-221X. ; 124:2, s. 81-91
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally imposed three different kinds of warming scenarios over 3 years on an alpine meadow community to identify the differential effects of climate warming and extreme climatic events on the abundance and biomass of bryophytes and lichens. Treatments consisted of (a) a constant level of warming with open top chambers (an average temperature increase of 1.87 A degrees C), (b) a yearly stepwise increase of warming (average temperature increases of 1.0; 1.87 and 3.54 A degrees C, consecutively), and (c) a pulse warming, i.e., a single first year pulse event of warming (average temperature increase of 3.54 A degrees C only during the first year). To our knowledge, this is the first climate change study that attempts to distinguish between the effects of constant, stepwise and pulse warming on bryophyte and lichen communities. We hypothesised that pulse warming would have a significant short-term effect compared to the other warming treatments, and that stepwise warming would have a significant mid-term effect compared to the other warming treatments. Acrocarpous bryophytes as a group increased in abundance and biomass to the short-term effect of pulse warming. We found no significant effects of mid-term (third-year) stepwise warming. However, one pleurocarpous bryophyte species, Tomentypnum nitens, generally increased in abundance during the warm year 1997 but decreased in control plots and in response to the stepwise warming treatment. Three years of experimental warming (all treatments as a group) did have a significant impact at the community level, yet changes in abundance did not translate into significant changes in the dominance hierarchies at the functional level (for acrocarpous bryophytes, pleurocarpous bryophytes, Sphagnum or lichens), or in significant changes in other bryophyte or lichen species. The results suggest that bryophytes and lichens, both at the functional group and species level, to a large extent are resistant to the different climate change warming simulations that were applied.
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| 6. |
- Alatalo, J. M., et al.
(författare)
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Impacts of different climate change regimes and extreme climatic events on an alpine meadow community
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Climate variability is expected to increase in future but there exist very few experimental studies that apply different warming regimes on plant communities over several years. We studied an alpine meadow community under three warming regimes over three years. Treatments consisted of (a) a constant level of warming with open-top chambers (ca. 1.9 degrees C above ambient), (b) yearly stepwise increases in warming (increases of ca. 1.0, 1.9 and 3.5 degrees C), and (c) pulse warming, a single first-year pulse event of warming (increase of ca. 3.5 degrees C). Pulse warming and stepwise warming was hypothesised to cause distinct first-year and third-year effects, respectively. We found support for both hypotheses; however, the responses varied among measurement levels (whole community, canopy, bottom layer, and plant functional groups), treatments, and time. Our study revealed complex responses of the alpine plant community to the different experimentally imposed climate warming regimes. Plant cover, height and biomass frequently responded distinctly to the constant level of warming, the stepwise increase in warming and the extreme pulse-warming event. Notably, we found that stepwise warming had an accumulating effect on biomass, the responses to the different warming regimes varied among functional groups, and the short-term perturbations had negative effect on species richness and diversity
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| 7. |
- Ali, A., et al.
(författare)
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Diversity-productivity dependent resistance of an alpine plant community to different climate change scenarios
- 2016
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Ingår i: Ecological Research. - : Wiley. - 0912-3814 .- 1440-1703. ; 31:6, s. 935-945
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Tidskriftsartikel (refereegranskat)abstract
- Here we report from a experiment imposing different warming scenarios [control with ambient temperature, constant level of moderate warming for 3 years, stepwise increase in warming for 3 years, and one season of high level warming (pulse) simulating an extreme summer event] on an alpine ecosystem to study the impact on species diversity-biomass relationship, and community resistance in terms of biomass production. Multiple linear mixed models indicate that experimental years had stronger influence on biomass than warming scenarios and species diversity. Species diversity and biomass had almost humpback relationships under different warming scenarios over different experimental years. There was generally a negative diversity-biomass relationship, implying that a positive diversity-biomass relationship was not the case. The application of different warming scenarios did not change this tendency. The change in community resistance to all warming scenarios was generally negatively correlated with increasing species diversity, the strength of the correlation varying both between treatments and between years within treatments. The strong effect of experimental years was consistent with the notion that niche complementarity effects increase over time, and hence, higher biomass productivity over experimental years. The strongest negative relationship was found in the first year of the pulse treatment, indicating that the community had weak resistance to an extreme event of one season of abnormally warm climate. Biomass production started recovering during the two subsequent years. Contrasting biomass-related resistance emerged in the different treatments, indicating that micro sites within the same plant community may differ in their resistance to different warming scenarios.
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| 8. |
- Antonson, Hans, et al.
(författare)
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Experiencing moose and landscape while driving : a simulator and questionnaire study
- 2014
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Ingår i: Journal of Environmental Psychology. - : Elsevier. - 0272-4944 .- 1522-9610. ; 41, s. 91-100
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Tidskriftsartikel (refereegranskat)abstract
- Animal vehicle collisions (AVC's) have large economic, medical and ecological consequences but have rarely been studied with respect to driver behaviour. The aim of this study was to investigate different AVC-relevant landscape settings (vegetation cover), with and without game fencing and in combination with encountering moose. Twenty-five participants took part in an advanced driving simulator experiment. The results show that neither the presence of a game fence nor vegetation was found to affect driving speed, speed variability, lateral position or visual scanning in general. When a moose appeared at the side of the road, the drivers reacted by slowing down earlier and reducing their speed more when no game fence was present. Furthermore, the speed reduction when a moose was present was significantly larger when the vegetation was sparse. Game fencing made drivers feel at ease whereas dense vegetation was experienced as more stressful.
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| 9. |
- Biurrun, Idoia, et al.
(författare)
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Benchmarking plant diversity of Palaearctic grasslands and other open habitats
- 2021
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Ingår i: Journal of Vegetation Science. - Oxford : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 32:4
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Tidskriftsartikel (refereegranskat)abstract
- Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology. © 2021 The Authors.
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| 10. |
- During, Heinjo J, et al.
(författare)
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Biomechanical properties of the terrestrial mosses Pleurozium schreberi (Brid.) Mitt. and Pogonatum japonicum Sull. & Lesq. along altitudinal gradients in northern Japan
- 2015
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Ingår i: Arctoa. - : KMK Scientific Press Ltd.. - 0131-1379. ; 24, s. 375-381
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Tidskriftsartikel (refereegranskat)abstract
- Altitudinal gradients along mountain slopes provide valuable opportunities to study variation in plant traits in response to changes in environmental conditions along such gradients. This study focused on biomechanical traits of two moss species, the more or less horizontally growing Pleurozium schreberi and the erect-growing Pogonatum japonicum, along altitudinal gradients on two mountains in Hokkaido, northern Japan.We measured stem diameter in two directions to determine the second moment of area I, used three-point bending tests with free stem ends to determine the slope of the force-deflection curve dF/dx, and used these data to calculate Young’s modulus and flexural rigidity of the stems. Both species showed much variation in all traits among replicates in the samples at each altitude. Environmental variation associated with altitude had more effect on the biomechanical traits of P. japonicum than on those of P. schreberi. Stems of P. japonicum were thicker (larger I) than those of P. schreberi and had a larger Young’s modulus and flexural rigidity. Stems tended to become thinner (lower second moment of area) and less rigid (lower flexural rigidity) at increasing altitude in both species.
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| 11. |
- Folkeson, Lennart, 1950-, et al.
(författare)
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State of preparedness for climate change adaptation in operations and maintenance of transport infrastructure in eight Swedish municipalities
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This study analysed the preparedness for climate change adaptation (CCA) of transport infrastructure in eight municipalities in Sweden. The study focused on municipal officials’ role in organizing and implementing CCA measures. The interviews were done in 2011. Many respondents confused CCA with climate change mitigation. Three of the municipalities had performed vulnerability analyses but apart from that, well-documented decision support in long-term adaptation was largely lacking. Adaptation measures were often based on day-to-day problems and recently experienced weather incidents. Strategic work with long-term CCA seemed to be largely lacking. The placing of the responsibility for CCA in the municipal organization was often unclear. Six of the respondents found there were no actual hindrances to their work with CCA and no conflicts with other municipal aims. However, several responses indicated budgetary competition with environmental aims or other societal strivings. The planning and implementation of CCA measures seemed to be highly dependent on individual officials, their engagement, their passivity/activity regarding this issue, their defined responsibility and the boundaries for their current position in the municipality organization.
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| 12. |
- Gren, Ing-Marie, et al.
(författare)
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Costs of air pollutants from shipping : a meta-regression analysis
- 2020
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Ingår i: Transport reviews. - : Taylor & Francis. - 0144-1647 .- 1464-5327. ; 40:4, s. 411-428
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Tidskriftsartikel (refereegranskat)abstract
- This study estimated the external cost of air pollution from shipping by means of a meta-regression analysis, which has not been made before. Three pollutants, which were included in most of the primary studies, were considered: nitrogen oxides (NOx), sulphur dioxides (SO2) and particulate matters with a diameter of max 2.5 micrometres (PM2.5). All primary studies included damages of health and a majority added impacts on agriculture and estimated the cost of air pollutants by transferring cost estimates from studies on costs of air emissions from transports in Europe. Different regression models and estimators were used and robust results were found of statistically significant emission elasticities of below one, i.e. total external costs increase by less than 1% when emissions increase by 1%. There was a small variation between the pollutants, with the highest elasticity for PM2.5 and lowest for NOx. Calculations of the marginal external cost of the pollutants showed the same pattern, with this cost being approximately six times higher for PM2.5 than for the other pollutants. Common to all pollutants was that the marginal external cost decreases when emission increases. Another robust result was a significant increase in the cost of studies published in journals compared with other publication outlets. These findings point out some caution when transferring constant external unit cost of air pollutant from shipping, which is much applied in the literature, and the cost functions estimated in this study could thus provide a complementary transfer mechanism.
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| 13. |
- Gren, Ing-Marie, et al.
(författare)
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Effects of shipping on non-indigenous species in the Baltic Sea
- 2022
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Ingår i: Science of the Total Environment. - Amsterdam : Elsevier. - 0048-9697 .- 1879-1026. ; 821
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Tidskriftsartikel (refereegranskat)abstract
- Shipping is regarded as an important vector for aquatic non-indigenous species (ANIS) worldwide. Less attention has been paid to its role in relation to environmental and economic causes of introduction and establishment, the knowledge of which is necessary to assess effects of changes in regulations on shipping. The purpose of this study was to estimate the impact of shipping on the incidence of ANIS in the Baltic Sea compared with environmental and economic factors. To this end, a production function was estimated with count data on ANIS (response variable) and shipping, environmental and economic factors as explanatory variables. Regression results from different regression models showed that shipping has a significant impact on ANIS incidence and can account for up to 38% of the number of ANIS in the sea. Predictions of the impact of measures implementing the Convention for the Control and Management of Ships' Ballast Water and Sediment indicated a reduction by 17% in the number of ANIS, which was counteracted by an expected increase in shipping traffic. © 2022
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| 14. |
- Idoia Biurrun, Idoia, et al.
(författare)
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GrassPlot v. 2.00 – first update on the database of multi-scale plant diversity in Palaearctic grasslands
- 2019
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Ingår i: Palaearctic Grasslands. - : Eurasian Dry Grassland Group (EDGG). - 2627-9827. ; :44, s. 26-47
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Tidskriftsartikel (refereegranskat)abstract
- GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phytocoenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems.
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| 15. |
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| 16. |
- Jägerbrand, Annika K., 1972-
(författare)
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Development of an indicator system for local governments to plan and evaluate sustainable outdoor lighting
- 2021
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Ingår i: Sustainability. - Basel : MDPI AG. - 2071-1050. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Outdoor lighting offers many benefits to its users and is often considered a necessity for an active lifestyle when living in modern society. Sustainable outdoor lighting should fulfil the functional needs of the users, be cost-and energy-efficient, and result in minimal environmental impact. So far, a limited number of studies have been able to present clear strategies on how to plan and use outdoor lighting to ensure that it contributes towards sustainable development. Therefore, this study aimed to answer the following questions: (1) How many of the previously established sustainability indicators are already used by municipalities in their lighting planning? (2) Which types of indicators are not used by municipalities? Another aim of the study was to further develop the framework of sustainability indicators by adding new indicators that were identified from lighting plans of Swedish municipalities and the existing literature. In this study, lighting master plans from 16 randomly chosen Swedish municipalities with varying population sizes were analyzed. The results show that few sustainable indicators are used by the municipalities’ lighting plans, especially in the social dimension. The existing framework of sustainability indicators was developed by adding new indicators. Furthermore, 28 new indicators were identified, eight originated from new studies and the literature, and 20 originated from the municipalities’ lighting master plans. This study shows that there is a need for guidelines and recommendations for working with outdoor lighting from a sustainability perspective, especially in the social dimension of sustainability, where most of the new indicators were identified. © 2021 by the author. Licensee MDPI, Basel, Switzerland.
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| 17. |
- Jägerbrand, Annika K., 1972-, et al.
(författare)
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Ecological impact of artificial light at night : Effective strategies and measures to deal with protected species and habitats
- 2021
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Ingår i: Sustainability. - Basel : MDPI. - 2071-1050. ; 13:11
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Forskningsöversikt (refereegranskat)abstract
- When conserving or protecting rare or endangered species, current general guidelines for reducing light pollution might not suffice to ensure long-term threatened species’ survival. Many protected areas are exposed to artificial light at levels with the potential to induce ecological impacts with unknown implications for the ecosystems they are designated to protect. Consequently, it is recommended that precautionary methods for the avoidance and mitigation of light pollution in protected areas be integrated into their management plans. This paper’s aims are to present an overview of best practices in precautionary methods to avoid and mitigate light pollution in protected areas and to identify and discuss what ecosystems should be considered light-sensitive and how to prioritise species and habitats that need protection from artificial light, including examples of legislation covering ecological light pollution in the European Union and in Sweden. The important aspects to include when considering light pollution at a landscape level are listed, and a proposal for prioritisation among species and habitats is suggested. Sensitive and conservation areas and important habitats for particularly vulnerable species could be prioritised for measures to minimise artificial lighting’s negative effects on biodiversity. This may be done by classifying protected natural environments into different zones and applying more constrained principles to limit lighting. The light pollution sensitivity of various environments and ecosystems suggests that different mitigation strategies and adaptations should be used depending on landscape characteristics, species sensitivity and other factors that may determine whether artificial light may be detrimental. Issues of the currently used measurement methods for artificial light at night are reviewed. We also propose and discuss the principles and benefits of using standardized measurement methods and appropriate instrumentation for field measurements of artificial light concerning the environmental impact of light pollution. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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| 18. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
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Effects of Climate Change on tundra bryophytes
- 2011
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Ingår i: Bryophyte Ecology and Climate Change. - Cambridge, UK : Cambridge University Press. - 9780521757775 ; , s. 211-236
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 19. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
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Effects of neighboring vascular plants on the abundance of bryophytes in different vegetation types
- 2012
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Ingår i: Polar Science. - Oxford : Elsevier BV. - 1873-9652 .- 1876-4428. ; 6:2, s. 200-208
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Tidskriftsartikel (refereegranskat)abstract
- Due to the climate change, vegetation of tundra ecosystems is predicted to shift toward shrub and tree dominance, and this change may influence bryophytes. To estimate how changes in growing environment and the dominance of vascular plants influence bryophyte abundance, we compared the relationship of occurrence of bryophytes among other plant types in a five-year experiment of warming (T), fertilization (F) and T + F in two vegetation types, heath and meadow, in a subarctic–alpine ecosystem. We compared individual leaf area among shrub species to confirm that deciduous shrubs might cause severe shading effect. Effects of neighboring functional types on the performance of Hylocomium splendens was also analyzed. Results show that F and T + F treatments significantly influenced bryophyte abundance negatively. Under natural conditions, bryophytes in the heath site were negatively related to the abundance of shrubs and lichens and the relationship between lichens and bryophytes strengthened after the experimental period. After five years of experimental treatments in the meadow, a positive abundance relationship emerged between bryophytes and deciduous shrubs, evergreen shrubs and forbs. This relationship was not found in the heath site. Our study therefore shows that the abundance relationships between bryophytes and plants in two vegetation types within the same area can be different. Deciduous shrubs had larger leaf area than evergreen shrubs but did not show any shading effect on H. splendens.
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| 20. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
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Effects of simulated shade on growth, number of branches and biomass in Hylocomium splendens and Racomitrium lanuginosum
- 2005
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Ingår i: Lindbergia. - 0105-0761 .- 2001-5909. ; 30:3, s. 117-124
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Tidskriftsartikel (refereegranskat)abstract
- The effects of simulated shade in terms of reduced light quantity (PPFD) and changed red:far-red ratio (R:FR ratio) on the growth in length, in number of branches and in biomass, were examined in a greenhouse experiment with Hylocomium splendens and Racomitrium lanuginosum, two species from habitats with different light conditions (with H. splendens often in more shaded microsites). Using ten intact moss turfs per species which had been collected on Iceland at 4 m distance between replicate turfs, we tested, whether light quantity affected growth and biomass, whether changes in light quantity and red:far-red ratio affected the number of branches, and whether the two species differed in these responses. Reduced light quantity (i.e. PPFD level) caused a greater length increase, decreased biomass, and biomass:length ratio in both species, but the magnitude of response varied greatly between species. Furthermore, in R. lanuginosum spectral shade (i.e. reduced PPFD and a lower R:FR ratio) generally caused stronger responses than neutral shade, with only a reduction in PPFD. H. splendens (from the shaded habitat) responded less strongly to the shade treatments than R. lanuginosum (from the open habitat) did. In addition to these effects of shading, there were strong effects of the turf of origin in both species, and in many cases the interaction between turf of origin and shading treatment was significant as well. Copyright © Lindbergia 2006.
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| 21. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
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Effects of weather conditions, light conditions, and road lighting on vehicle speed
- 2016
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Ingår i: SpringerPlus. - : Springer Science and Business Media LLC. - 2193-1801. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Light conditions are known to affect the number of vehicle accidents and fatalities but the relationship between light conditions and vehicle speed is not fully understood. This study examined whether vehicle speed on roads is higher in daylight and under road lighting than in darkness, and determined the combined effects of light conditions, posted speed limit and weather conditions on driving speed. The vehicle speed of passenger cars in different light conditions (daylight, twilight, darkness, artificial light) and different weather conditions (clear weather, rain, snow) was determined using traffic and weather data collected on an hourly basis for approximately 2 years (1 September 2012–31 May 2014) at 25 locations in Sweden (17 with road lighting and eight without). In total, the data included almost 60 million vehicle passes. The data were cleaned by removing June, July, and August, which have different traffic patterns than the rest of the year. Only data from the periods 10:00 A.M.–04:00 P.M. and 06:00 P.M.–10:00 P.M. were used, to remove traffic during rush hour and at night. Multivariate adaptive regression splines was used to evaluate the overall influence of independent variables on vehicle speed and nonparametric statistical testing was applied to test for speed differences between dark–daylight, dark–twilight, and twilight–daylight, on roads with and without road lighting. The results show that vehicle speed in general depends on several independent variables. Analyses of vehicle speed and speed differences between daylight, twilight and darkness, with and without road lighting, did not reveal any differences attributable to light conditions. However, vehicle speed decreased due to rain or snow and the decrease was higher on roads without road lighting than on roads with lighting. These results suggest that the strong association between traffic accidents and darkness or low light conditions could be explained by drivers failing to adjust their speed to the reduced visibility in dark conditions.
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| 22. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
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Energiutvinning ur vägar och vägmiljöer : en kunskapsöversikt
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapportens syfte är att kartlägga nya energitekniker för energiutvinning och möjligheten att använda dem i väg- och vägmiljöområden. Kartläggningen fokuserar på material och metoder som kan komma att användas under svenska (kalla) förhållanden. Rapporten kan vara användbar för planering av ny infrastruktur då man vill använda sig av förnyelsebar energi under nordiska kalla förhållanden och man vill minska miljöbelastningen. Den kan också utgöra stöd för prioriteringen av Trafikverkets framtida forskningsprojekt. Med dagens tekniska förutsättningar kan följande tekniker vara aktuella: Solceller i till exempel bullerskydd, solceller i väg, geotermisk energi, piezoelektrisk teknik, vindenergi och bioenergi. Det finns dock många faktorer som håller tillbaka utvecklingen av nya innovativa system för energiutvinning. Några viktiga orsaker är exempelvis att underhållskostnaderna kan öka eller att underhållet av vägen försvåras.
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| 23. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
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Kan viltolyckor förebyggas av körsätt? : En körsimulatorstudie utförd av VTI. Slutrapport till Viltvårdsfonden, projekt nr 802-0224-09
- 2013
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Rapport (populärvet., debatt m.m.)abstract
- Projektets syfte har varit att förstå mänskligt förarbeteende i situationer där vilt förekommer utmed vägmiljöer och även att undersöka vilka effekter förebyggande åtgärder har på förarbeteendet. Om det går att förstå förarbeteende bättre, samt undersöka exakt hur de förebyggande åtgärderna som skall förhindra viltkollisioner fungerar på människor, finns både goda möjligheter att reducera antalet viltkollisioner (oavsett viltstammens storlek), och ändra allmänhetens uppfattning av att det enbart är storleken på viltstammarna som gör att man kolliderar med vilt.Vi har utfört en körsimulatorstudie i SIM III där det ingick 25 försökspersoner, 10 män och 15 kvinnor. Försökspersonerna fick köra sträckor med en full-faktoriell design innehållande testvariablerna: ATK (hastighetskamera), riktat radiomeddelande, viltvarningsskylt, älg, viltstängsel samt öppet landskap och landskap med tät skog.Älgen förefaller vara den variabel som leder till störst reaktioner, även vad gäller stress. Det kan bero på att man inte är van att se älgar längs vägarna. Vi vet inte om det går att vänja sig vid detta, men då reaktionen av älg vid upprepning förefaller mildra effekterna av såväl stress som inbromsning tyder resultaten på att så kan vara fallet.Föreliggande studie har identifierat forskningsbehov inom flera områden såsom djupgående studier av att undersöka huruvida effekter av de förebyggande åtgärderna har en ihållande effekt på längre sikt, dvs. efter upprepningar. Annars föreligger en risk att förebyggande åtgärder (radiomeddelande, älg, ATK, varningsskylt), endast har en kortvarig effekt.
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| 24. |
- Jägerbrand, Annika K, 1972-
(författare)
-
Kollisioner och olyckor med rådjur i Sverige under 10 år (2003–2012) : variation i tid, geografi och kostnader
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Målen med detta projekt var att skapa en 10-årig översikt över antalet rådjurskollisioner i Sverige och olyckornas variation i tid, geografi och kostnader, både avseende egendomsskador och personskadeolyckor. Olycksstatistik från NVR, Nationella viltolycksrådet (kollisioner), Strada (personskadeolyckor i Swedish Traffic Accident Data Acquisition) och Ofelia (system för järnväg) har använts. Resultaten visar att antalet rådjurskollisioner ökat under 10-årsperioden. Totalt antal rådjursolyckor som blivit inrapporterade under åren 2003–2012 är 306 267 (egendomsskador och personskadeolyckor) medan antalet omkomna och skadade personer i dessa olyckor är 2 752. Ökningen i antalet rådjurskollisioner har varit betydligt större i de nordligaste länen och Gotland. Antalet rådjurskollisioner är betydligt fler under försommaren (maj–juni) och tidigt på vintern (oktober–december), medan antalet personskadeolyckor med rådjur är högst under sommaren. Antalet rådjurskollisioner varierar under dygnet men flest kollisioner och olyckor sker under morgon och kväll för både egendomsskador och personskadeolyckor. För antalet omkomna i olyckor med rådjur inblandade är antalet dubbelt så stort än de officiellt rapporterade antalen, medan antalet svårt skadade är minst 177 % högre än de officiella siffrorna. Det är troligt att den officiella statistiken även underskattar antalet dödade och skadade från övriga viltslag såsom älg, hjort och vildsvin. Denna studie visar att totala kostnaderna för rådjurskollisioner och rådjursolyckor 2012 överstiger 1 miljard kronor varav cirka 70 % är kostnader för egendomsskador.
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| 25. |
- Jägerbrand, Annika K, 1972-
(författare)
-
LED (Light-Emitting Diode) road lighting in practice : An evaluation of compliance with regulations and improvements for further energy savings
- 2016
-
Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 9:5
-
Tidskriftsartikel (refereegranskat)abstract
- Light-emitting diode (LED) road lighting has been widely implemented in recent years, but few studies have evaluated its performance after installation. This study investigated whether LED road lighting complies with minimum regulations in terms of traffic safety and whether improvements for energy efficiency are possible. Average road surface luminance (L), overall luminance uniformity (U0), longitudinal luminance uniformity (U1), power density (PD) and normalised power density (PN) were evaluated for 14 roads (seven designed for vehicular traffic and seven for pedestrians and bicycles). Energy savings were calculated as the percentage reduction to the minimum level of the existing lighting class or a lower lighting class and by applying a dimming schedule. The results showed that LED road lighting for vehicular traffic roads generally fulfilled the requirements, whereas that for pedestrian and bicycle roads generally corresponded to the lowest lighting class for L, and often did not meet the statutory requirements for U0 and UI. By adapting lighting levels to the minimum requirement of the existing lighting class or by dropping to a lower lighting class, vehicular traffic roads could save 6%-35% on L to lighting class M5 and 23%-61% on L to lighting class M6. A dimming schedule could lead to energy savings of 49%. There is little potential for savings on pedestrian and bicycle roads, except by implementing a dimming schedule. Thus, in general, for vehicular, pedestrian and bicycle roads, a dimming schedule can save more energy than can be achieved in general by reducing lighting class. Furthermore, since a dimming schedule can be adjusted to traffic intensity, any potential risk of compromising traffic safety is minimised.
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| 26. |
- Jägerbrand, Annika K., 1972-, et al.
(författare)
-
Measures for reducing the adverse effects of artificial light at night : inter-disciplinary development and progress
- 2021
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The use of artificial light at night in the outdoor environment may introduce negative andunwanted side-effects such as light pollution and unwanted impacts on humans, ecosystemsand biodiversity. Therefore, appropriate measures for reducing the adverse effects of artificiallight at night are important to establish a sustainable use of outdoor lighting. This paperpresents an updated overview and a state-of-the-art of available and effective measures forreducing artificial light at night, which range from strategical and high-level recommendationsto more practical and applicable lighting design recommendations and principles. Another aimis to identify prioritized future research questions and areas that will enhance progress withinthe area. We present the current recommendations into three groups: (I) recommendations forlegislation at the national or international levels, (II) recommendations for technical andpractical adaptations of the lighting design and (III) recommendations for sensitive species,taxa, areas or ecosystems.
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| 27. |
- Jägerbrand, Annika K, 1972-
(författare)
-
New Framework of Sustainable Indicators for Outdoor LED (Light Emitting Diodes) Lighting and SSL (Solid State Lighting)
- 2015
-
Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 7:1, s. 1028-1063
-
Tidskriftsartikel (refereegranskat)abstract
- Light emitting diodes (LEDs) and SSL (solid state lighting) are relatively new light sources, but are already widely applied for outdoor lighting. Despite this, there is little available information allowing planners and designers to evaluate and weigh different sustainability aspects of LED/SSL lighting when making decisions. Based on a literature review, this paper proposes a framework of sustainability indicators and/or measures that can be used for a general evaluation or to highlight certain objectives or aspects of special interest when choosing LED/SSL lighting. LED/SSL lighting is reviewed from a conventional sustainable development perspective, i.e., covering the three dimensions, including ecological, economic and social sustainability. The new framework of sustainable indicators allow prioritization when choosing LED/SSL products and can thereby help ensure that short-term decisions on LED/SSL lighting systems are in line with long-term sustainability goals established in society. The new framework can also be a beneficial tool for planners, decision-makers, developers and lighting designers, or for consumers wishing to use LED/SSL lighting in a sustainable manner. Moreover, since some aspects of LED/SSL lighting have not yet been thoroughly studied or developed, some possible future indicators are suggested.
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| 28. |
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| 29. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
-
Phenotypic variation at different spatial scales in relation to environment in two circumpolar bryophyte species
- 2005
-
Ingår i: Lindbergia. - : ABE-IPS. - 0105-0761 .- 2001-5909. ; 30:3, s. 125-142
-
Tidskriftsartikel (refereegranskat)abstract
- Morphology, physiology and biomass in two widespread bryophyte species, Hylocomium splendens and Racomitrium lanuginosum, were studied to examine the extent to which different species exhibit similar phenotypic variation patterns within and across regions. Analyses of nine morphological variables, chlorophyll content, nitrogen content, C/N ratio and biomass were conducted in samples from five sites in two geographically separated and climatically different regions, Iceland and northern Sweden. Both species exhibited large between-site variation in morphology, physiology and biomass, but within-site variation in morphology was substantially higher in Hylocomium splendens than Racomitrium lanuginosum. Morphological patterns were partly similar, partly different between the species, indicating that the two species respond morphologically to external factors on different scales. The lowest concentrations of chlorophyll and nitrogen were found at the same sites for both species, while the site of highest concentration was not the same. In Hylocomium splendens, chlorophyll content was positively correlated with biomass. Many of the observed relationships between morphological, physiological variables and biomass were species-specific. Our results demonstrate that the two bryophytes exhibit different phenotypic responses to environmental variation. Copyright © Lindbergia 2006.
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| 30. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
-
Plant community responses to 5 years of simulated climate change in meadow and heath ecosystems at a subarctic-alpine site
- 2009
-
Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 161:3, s. 601-610
-
Tidskriftsartikel (refereegranskat)abstract
- Climate change was simulated by increasing temperature and nutrient availability in an alpine landscape. We conducted a field experiment of BACI-design (before/after control/impact) running for five seasons in two alpine communities (heath and meadow) with the factors temperature (increase of ca. 1.5-3.0°C) and nutrients (5 g N, 5 g P per m 2) in a fully factorial design in northern Swedish Lapland. The response variables were abundances of plant species and functional types. Plant community responses to the experimental perturbations were investigated, and the responses of plant functional types were examined in comparison to responses at the species level. Nutrient addition, exclusively and in combination with enhanced temperature increase, exerted the most pronounced responses at the species-specific and community levels. The main responses to nutrient addition were increases in graminoids and forbs, whereas deciduous shrubs, evergreen shrubs, bryophytes, and lichens decreased. The two plant communities of heath or meadow showed different vegetation responses to the environmental treatments despite the fact that both communities were located on the same subarctic-alpine site. Furthermore, we showed that the abundance of forbs increased in response to the combined treatment of temperature and nutrient addition in the meadow plant community. Within a single-plant functional type, most species responded similarly to the enhanced treatments although there were exceptions, particularly in the moss and lichen functional types. Plant community structure showed BACI responses in that vegetation dominance relationships in the existing plant functional types changed to varying degrees in all plots, including control plots. Betula nana and lichens increased in the temperature-increased enhancements and in control plots in the heath plant community during the treatment period. The increases in control plots were probably a response to the observed warming during the treatment period in the region. © Springer-Verlag 2009.
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| 31. |
- Jägerbrand, Annika K, 1972-, et al.
(författare)
-
Renewal of street and road lighting in Swedish municipalities
- 2013
-
Ingår i: Proceedings of CIE Centenary Conference "Towards a New Century of Light", April 15-16, Paris, France, 2013.. - CIE. - 9783902842442 ; , s. 1009-1015
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We studied planning, responsibilities, and stakeholder’s involvement in 12 Swedish municipalities of different size to identify factors that could constitute barriers for developing more energy efficient street and road lighting (SRL). In this study, small municipalities had the most energy efficient lighting and all stated that energy savings were the main reason for their substitution of mercury lamps. In medium-sized and large municipalities the ecodesign directive was given as the main motive for renewal of the SRL by four municipalities, and the remaining four municipalities stated that their main motive was the need to replace old SRL. Outsourcing of management, operation and maintenance may constitute a barrier for renewal whereas lack of knowledge and costs for renewal does not seem to be any significant barriers. Integration of SRL planning with other strategies, such as energy and economy strategies, seems to be an important factor for a proactive SRL development.
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| 32. |
- Jägerbrand, Annika K., 1972-
(författare)
-
Synergies and Trade-offs between sustainable development and energy performance of exterior lighting
- 2020
-
Ingår i: Energies. - : MDPI. - 1996-1073. ; 13:9
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this review was tomap synergies and trade-offs between sustainable development and energy efficiency and savings regarding exterior lighting. Exterior lighting, such as public road and street lighting, requires significant amounts of energy and hinders sustainable development through its increasing of light pollution, ecological impact, and global climate change. Interlinkages between indicators in sustainability and energy that have positive interactions will lead to a mutual reinforcement in the decision-making process, and vice versa, interlinkages between trade-offs may lead to unwanted and conflicting effects. Very few studies have presented a clear vision of how exterior lighting should be contributing to, and not counteracting, the sustainable development of our planet. This study was conducted through a theoretical and systematic analysis that examined the interactions between sustainable development and energy performance based on a framework using indicators and variables, and by reviewing the current literature. Additionally, 17 indicators of energy efficiency and energy savings were identified and used in the analysis. Most interactions between variables for sustainable development and energy performance (52%) were found to be synergistic. The synergistic interactions were mostly found (71%) in the ecological and environmental dimension showing that environmental and ecological sustainability goes hand in hand with energy efficiency and savings. Trade-offs were found only in the economic and social dimensions accounting for 18% of the interactions identified. This review shows that the interactions between sustainable development and energy performance can be used to establish more efficient policies for decision-making processes regarding exterior lighting.
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| 33. |
- Jägerbrand, Annika K, 1972-
(författare)
-
Trafiksäkerhets- och trygghetsaspekter i samspelet mellan gatumiljöns utformning och en mer energieffektiv belysning
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektets syfte var att studera trafiksäkerhetsaspekter i ny belysning och deras samspel med gatumiljön för oskyddade trafikanter. Projektet undersökte således belysningsförutsättningar, påverkan på cyklister, samspelet mellan belysning, trafiksäkerhet, gatumiljö och/eller andra effekter såsom trygghet, gällande tre olika ljuskällor och typer av belysning (kvicksilver 125W, keramisk metallhalogen 70W samt LED 25W) belägna i ungefär samma typ av gatumiljö på en gång- och cykelväg på Kungsholms strand i Stockholm. Resultaten visar att energiåtgången för LED är 28 % av traditionell kvicksilverbelysning och 49 % av keramisk metallhalogenbelysning. Denna studie visar att det är möjligt att få tillräckliga jämnhetsnivåer med LED-belysning men att detta är beroende av armaturens utformning, design och antalet stolpar per meter väg (i detta fall 15,3 m stolpavstånd). I denna undersökning påvisades inga skillnader i cykelhastighet för LED-belysning mellan dagsljus och mörker eller mellan olika typer av belysning. Analyser av trygghetsaspekter fungerade bra att göra baserat på enkla uppskattningar av hur bra belysningen fungerar (genom analys av digitala foton) och till exempel upplevelse av synbarhet stämmer mycket bra överens med de uppmätta fysikaliska belysningsmåtten.
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| 34. |
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| 35. |
- Lett, Signe, et al.
(författare)
-
Can bryophyte groups increase functional resolution in tundra ecosystems?
- 2022
-
Ingår i: Arctic Science. - Ottawa : Canadian Science Publishing. - 2368-7460. ; 8:3, s. 609-637
-
Tidskriftsartikel (refereegranskat)abstract
- The relative contribution of bryophytes to plant diversity, primary productivity, and ecosystem functioning increases towards colder climates. Bryophytes respond to environmental changes at the species level, but because bryophyte species are relatively difficult to identify, they are often lumped into one functional group. Consequently, bryophyte function remains poorly resolved. Here, we explore how higher resolution of bryophyte functional diversity can be encouraged and implemented in tundra ecological studies. We briefly review previous bryophyte functional classifications and the roles of bryophytes in tundra ecosystems and their susceptibility to environmental change. Based on shoot morphology and colony organization, we then propose twelve easily distinguishable bryophyte functional groups. To illustrate how bryophyte functional groups can help elucidate variation in bryophyte effects and responses, we compiled existing data on water holding capacity, a key bryophyte trait. Although plant functional groups can mask potentially high interspecific and intraspecific variability, we found better separation of bryophyte functional group means compared with previous grouping systems regarding water holding capacity. This suggests that our bryophyte functional groups truly represent variation in the functional roles of bryophytes in tundra ecosystems. Lastly, we provide recommendations to improve the monitoring of bryophyte community changes in tundra study sites.
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| 36. |
- Little, Chelsea J., et al.
(författare)
-
Community and species-specific responses to simulated global change in two subarctic-alpine plant communities
- 2015
-
Ingår i: Ecosphere. - : ESA. - 2150-8925 .- 2150-8925. ; 6:11
-
Tidskriftsartikel (refereegranskat)abstract
- Long-term observational studies have detected greening and shrub encroachment in the subarctic attributed to current climate change, while global change simulations have showed that community composition and productivity may shift drastically in arctic, subarctic, and alpine tundra plant communities in the future. However, responses to global change can be highly species-and context-dependent. We examined community-level and species-specific responses to a six-year factorial temperature and nutrient (nitrogen and phosphorus) amendment experiment in two alpine plant communities in northern Sweden: a species-poor dwarf shrub heath, and a more species-rich meadow. We hypothesized that abundance responses to global change would be variable within commonly defined vascular plant functional groups (e.g., forbs, evergreen shrubs, deciduous shrubs) and that new species would appear in experimental plots over time due to the ameliorated growing conditions. We found that within most functional groups, species were highly individualistic with respect to the global change simulation, particularly within the forbs, whereas within the shrubs, responses were neutral to negative and widely variable in magnitude. In the heath community the response of the graminoid functional group was driven almost entirely by the grass Calamagrostis lapponica, which increased in abundance by an order of magnitude in the combined temperature and nutrient treatment. Furthermore, community context was important for species' responses to the simulations. Abundance of the pan-arctic species Carex bigelowii and Vaccinium vitis-idaea responded primarily to the temperature treatment in the meadow community whereas the nutrient treatment had stronger effects in the heath community. Over six growing seasons, more new species appeared in the experimental plots than in control plots in the meadow community, whereas in the heath community only one new species appeared. Our results from two closely situated but different plant communities show that functional groups do not predict individual species responses to simulated global change, and that these responses depend to a large extent on pre-existing physical conditions as well as biotic interactions such as competition and facilitation. It may be difficult to apply general trends of global change responses to specific local communities.
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| 37. |
- Nilsson Tengelin, M., et al.
(författare)
-
A Novel Method for Studying Threshold Levels for Positive Phototaxis in Insects
- 2021
-
Ingår i: CIE x048. - Vienna : CIE Central Bureau. - 9783902842299 ; , s. 262-268
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a novel method for studying threshold levels for positive phototaxis ofinsects and smaller mobile organisms. Outdoor lighting affects light sensitive species and thereis a need to evaluate the effect of light levels, spectral composition of the light and lightdistribution to mitigate the ecological impacts of the artificial light. For this purpose, a test boxinvestigating the effect of light on insects in a controlled manner has been constructed. The boxis equipped with a luminance source and the light levels can be varied from a maximum valuecontinuously down to zero. The spectral composition of the light can be varied by changing thelamp or using optical filters. For visibility of the insects the box has infrared light emitting diodesin the ceiling and two wide-angle cameras monitor the light response. The functionality of thebox is tested with the species greater wax moth.
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| 38. |
- Pracki, Piotr, et al.
(författare)
-
Application of road lighting energy efficiency evaluation system in practice
- 2013
-
Ingår i: Proceedings of CIE Centenary Conference "Towards a New Century of Light". - 9783902842442 ; , s. -1043
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this paper is to introduce the energy efficiency evaluation system of road lighting for roads with vehicle traffic. The most important information regarding the proposed road lighting energy efficiency system is given. The subsequent stages of the road lighting energy efficiency evaluation are indicated with some detailed considerations. The energy efficiency classifications based on normalised power (energy) density and power (energy) density are presented as well. Examples of lighting energy efficiency evaluation to show the application of the system for selected streets in Stockholm and Warsaw are presented.
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| 39. |
- Rawat, Monika, et al.
(författare)
-
Litter decomposition above the treeline in alpine regions : A mini review
- 2021
-
Ingår i: Acta Oecologica. - Issy-les-Moulineaux : Elsevier. - 1146-609X .- 1873-6238. ; 113
-
Forskningsöversikt (refereegranskat)abstract
- Litter decomposition is a key driver of ecosystem processes and carbon cycling. Decomposition rate is influenced by numerous factors, such as temperature, humidity, litter properties, soil properties, and properties of soil fauna/microbial communities. The aim of this review was to summarize current knowledge on litter decomposition above the treeline in alpine regions worldwide and identify: I) factors that have been studied in great detail, II) factors that have been less intensively investigated, III) geographical regions that have been less well studied, and IV) factors with consistent or inconsistent effects on decomposition. The review showed inconsistent results for all factors covered by two or more studies regarding their effect on decomposition rate (positive, negative, no effect), usually a result of interactions between factors. Studies examining one or several factors in the physical environment (i.e., altitude, experimental warming, microclimate, snow cover and soil moisture) were most common, while studies on different aspects of resource quality were the second most common. The impacts of trophic interactions on soil microbes and fauna were less frequently studied. Europe and Asia were the best-represented regions, in terms of number of studies and geographical distribution, while there were no studies from Africa and very few from South America and Australia. North American studies were all from Colorado, and those from Asia were all from China. In order to obtain better global representation, there is a need for studies in Africa, South America, and Australia. There is also a need for more studies to explain the large variation in responses of litter decomposition rates to different influencing factors in alpine environments. Future research should focus on interactions between different factors and on experiments testing specific relationships, such as the potential interaction between temperature and soil moisture and its effect on litter decomposition above the treeline in alpine regions. © 2021 The Authors
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| 40. |
- Rawat, Monika, et al.
(författare)
-
Visitors off the trail : Impacts on the dominant plant, bryophyte and lichen species in alpine heath vegetation in sub-arctic Sweden
- 2021
-
Ingår i: Environmental Challenges. - Amsterdam : Elsevier. - 2667-0100. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- Alpine ecosystems are under increasing pressure due to tourism and recreational activities. When leaving desig- nated trails as is frequently observed, visitors can cause unintentional damage to vegetation. This study investi- gated the effect of human trampling on the dominant species of vascular plants, bryophytes and lichens along an infrequently used hiking trail in an alpine ecosystem in sub-arctic Sweden. The hypothesis tested was that prox- imity to the trail (as an effect of more people leaving the trail for a short distance compared to a longer distance) causes a decrease in species with low resistance to trampling. With a greater decrease in taller forbs and shrubs than in graminoids and prostrate plants, a greater decrease in lichen than in bryophyte species, and a change in vegetation composition. The results showed that proximity to the trail did not cause a decrease in the majority of dominant species, with none of the eight most dominant vascular plants showing any significant effects of prox- imity to the trail. One bryophyte species (Dicranum elongatum) among the six most commonly found decreased with proximity to the trail. Three lichen species (Cladonia arbuscula, Cladonia uncinalis, Ochrolechia frigida) among the eight most common species decreased with proximity to the trail. There was no evidence that taller species decreased with proximity to the trail, although the deciduous shrub Betula nana showed a tendency for a decrease. Proximity to the trail caused a greater decrease in lichen species than in bryophyte species. Multivariate analyses showed that distance from trail and transect direction had significant effects on overall vegetation composition. The level of low-intensity trampling recorded indicates that current numbers of hikers at the site can be sustained for longer periods with minimum impact on vascular plant species, but to get a more general understanding of the impact of low-intensity trampling data from additional sites are needed. © 2021 The Author(s)
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| 41. |
- Robertson, Kerstin, 1961-, et al.
(författare)
-
Evaluation of transport interventions in developing countries
- 2015
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- International climate policy and the United Nations Framework Convention on Climate Change (UNFCCC) with the Kyoto Protocol include different mechanisms or programmes for actions in developing countries aimed at reducing emissions of carbon dioxide (CO2). To verify compliance, the effects of such actions, including transport measures, need to be measured, reported and verified (MRV). However, in relation to other sectors very few transport-related projects have been initiated. Potential problems and ambiguities related to the current evaluation methodology were therefore investigated as a possible explanation for the low interest in investments in the transport sector. Other objectives of this study were to analyse the requirements for development and improvement of methods for evaluating the effects of transport policies and measures on emissions of greenhouse gases in developing countries. The analyses includes a review of different climate mechanisms, for example applied within the UNFCCC, evaluation requirements and methodologies used, the general availability of methods for evaluation of traffic and transportation, evaluation data availability, and institutional conditions in developing countries. The main conclusions are that measuring traffic and transportation is generally a complex and demanding process, and the potential for misinterpretation of results is significant. In addition, there is a significant risk of rebound effects, especially for transport projects in developing countries aiming at modal shift. Furthermore, it seems that very short time frames are applied for evaluation of project-based mechanisms in the transport sector. Other challenges relate to institutional roles and responsibilities, the availability of personal and financial resources, and the knowledge and perspectives applied. Based on these limitations regarding transport project evaluations, further development of transport-related climate mechanisms towards a more sectoral and transformational perspective is suggested.
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| 42. |
- Scharn, Ruud, et al.
(författare)
-
Vegetation responses to 26 years of warming at Latnjajaure Field Station, northern Sweden
- 2022
-
Ingår i: Arctic Science. - Ottawa, ON : Canadian Science Publishing. - 2368-7460. ; 8:3, s. 858-877
-
Tidskriftsartikel (refereegranskat)abstract
- Climate change is rapidly warming high latitude and high elevation regions influencing plant community composition. Changes in vegetation composition have motivated the coordination of ecological monitoring networks across the Arctic, including the International Tundra Experiment. We have established a long-term passive warming experiment using open-top chambers, which includes five distinct plant communities (Dry Heath; Tussock Tundra; and Dry, Mesic, and Wet Meadow). We measured changes in plant community composition based on relative abundance differences over 26 years. In addition, relative abundance changes in response to fertilization and warming treatments were analyzed based on a seven-year Community-Level Interaction Program experiment. The communities had distinct soil moisture conditions, leading to community-specific responses of the plant growth forms (deciduous shrubs, evergreen shrubs, forbs, and graminoids). Warming significantly affected growth forms, but the direction of the response was not consistent across the communities. Evidence of shrub expansion was found in nearly all communities, with soil moisture determining whether it was driven by deciduous or evergreen shrubs. Graminoids increased in relative abundance in the Dry Meadow due to warming. Growth form responses to warming are likely mediated by edaphic characteristics of the communities and their interactions with climate.
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| 43. |
- Wänström Lindh, Ulrika, et al.
(författare)
-
Impact of qualitative and quantitative methods on the evaluation of street lighting uniformity
- 2021
-
Ingår i: Proceedings of the Conference CIE 2021. ; , s. 413-422
-
Konferensbidrag (refereegranskat)abstract
- Uniformity of lighting for pedestrians is often assumed to have been achieved in mixed traffic environments when the lighting uniformity requirements for vehicular traffic have been fulfilled. Uniformity of lighting for drivers is commonly evaluated based on quantitative data on parameters such as overall luminance uniformity. However, methods for evaluating uniformity from the perspective of other road users are currently somewhat lacking. This study discusses qualitative and quantitative methods of assessing street lighting uniformity, and the potential implications for lighting design and the road users. We used convergence design and imbedded design based on two field studies. The research purpose is twofold: first, to study if, and how, measured lighting uniformity corresponds with visual perception. Secondly, to identify and explain the additional value that a combined method approach can contribute. The study considers examples of when the measured uniformity corresponds to visually perceived uniformity and when they do not correspond.
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- Wänström Lindh, Ulrika, et al.
(författare)
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Perceived Lighting Uniformity on Pedestrian Roads : From an Architectural Perspective
- 2021
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Ingår i: Energies. - Basel : MDPI. - 1996-1073. ; 14:12
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Tidskriftsartikel (refereegranskat)abstract
- Lighting uniformity is a key factor in traffic safety, and it could even result in energy savings for light installations. However, highly uniform horizontal road lighting for motorized vehicles may not be optimal for pedestrian roads. Therefore, it is important to evaluate the way in which pedestrians experience road lighting uniformity. Accordingly, we employed a qualitative approach to examine pedestrian road lighting uniformity. Visual analyses were used to exemplify and discuss the perceived uniformity. The case studies were performed on three pedestrian roads with similar light installations. The results show that the experience of road lighting uniformity differs substantially between the three roads. Based on the case studies, there are many aspects that need to be considered beyond the light falling on the horizontal surfaces. This study suggests that the visual experience of road lighting uniformity for pedestrians is difficult to estimate with photometric values because the visual impact of uniformity is highly influenced by the spatial context and landscape.
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