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  • 1. Alatalo, Juha M.
    et al.
    Jägerbrand, Annika K.
    Chen, Shengbin
    Molau, Ulf
    Responses of lichen communities to 18 years of natural and experimental warming2017In: Annals of Botany, ISSN 0305-7364, E-ISSN 1095-8290, Vol. 120, no 1, p. 159-170Article in journal (Refereed)
    Abstract [en]

    Background and Aims 

    Climate change is expected to have major impacts on high alpine and arctic ecosystems in the future, but empirical data on the impact of long-term warming on lichen diversity and richness are sparse. This study report the effects of 18 years of ambient and experimental warming on lichens and vascular plant cover in two alpine plant communities, a dry heath with sparse canopy cover (54 %) and a mesic meadow with a more developed (67 %) canopy cover, in sub-arctic Sweden.

    Methods 

    The effects of long-term passive experimental warming using open top chambers (OTCs) on lichens and total vascular plant cover, and the impact of plant cover on lichen community parameters, were analysed.

    Key Results 

    Between 1993 and 2013, mean annual temperature increased about 2 °C. Both site and experimental warming had a significant effect on cover, species richness, effective number of species evenness of lichens, and total plant canopy cover. Lichen cover increased in the heath under ambient conditions, and remained more stable under experimental warming. The negative effect on species richness and effective number of species was driven by a decrease in lichens under experimental warming in the meadow. Lichen cover, species richness, effective number of species evenness were negatively correlated with plant canopy cover. There was a significant negative impact on one species and a non-significant tendency of lower abundance of the most common species in response to experimental warming.

    Conclusions 

    The results from the long-term warming study imply that arctic and high alpine lichen communities are likely to be negatively affected by climate change and an increase in plant canopy cover. Both biotic and abiotic factors are thus important for future impacts of climate change on lichens.

  • 2. Alatalo, Juha M.
    et al.
    Jägerbrand, Annika K.
    Calluna AB, Nacka, Sweden.
    Juhanson, Jaanis
    Michelsen, Anders
    Ľuptáčik, Peter
    Impacts of twenty years of experimental warming on soil carbon, nitrogen, moisture and soil mites across alpine/subarctic tundra communities2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7Article in journal (Refereed)
    Abstract [en]

    High-altitude and alpine areas are predicted to experience rapid and substantial increases in future temperature, which may have serious impacts on soil carbon, nutrient and soil fauna. Here we report the impact of 20 years of experimental warming on soil properties and soil mites in three contrasting plant communities in alpine/subarctic Sweden. Long-term warming decreased juvenile oribatid mite density, but had no effect on adult oribatids density, total mite density, any major mite group or the most common species. Long-term warming also caused loss of nitrogen, carbon and moisture from the mineral soil layer in mesic meadow, but not in wet meadow or heath or from the organic soil layer. There was a significant site effect on the density of one mite species, Oppiella neerlandica, and all soil parameters. A significant plot-scale impact on mites suggests that small-scale heterogeneity may be important for buffering mites from global warming. The results indicated that juvenile mites may be more vulnerable to global warming than adult stages. Importantly, the results also indicated that global warming may cause carbon and nitrogen losses in alpine and tundra mineral soils and that its effects may differ at local scale.

  • 3. Alatalo, Juha M.
    et al.
    Jägerbrand, Annika K.
    Molau, Ulf
    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 tundra2014In: Alpine Botany, ISSN 1664-2201, E-ISSN 1664-221X, Vol. 124, no 2, p. 81-91Article in journal (Refereed)
    Abstract [en]

    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 °C), (b) a yearly stepwise increase of warming (average temperature increases of 1.0; 1.87 and 3.54 °C, consecutively), and (c) a pulse warming, i.e., a single first year pulse event of warming (average temperature increase of 3.54 °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.

  • 4.
    Alatalo, Juha M.
    et al.
    Qatar University.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Molau, Ulf
    Göteborgs Universitet.
    Impacts of different climate change regimes and extreme climatic events on an alpine meadow community2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 21720Article in journal (Refereed)
    Abstract [en]

    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 °C above ambient), (b) yearly stepwise increases in warming (increases of ca. 1.0, 1.9 and 3.5 °C), and (c) pulse warming, a single first-year pulse event of warming (increase of ca. 3.5 °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.

  • 5.
    Alatalo, Juha M.
    et al.
    Uppsala Universitet.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Molau, Ulf
    University of Gothenburg.
    Seven years of experimental warming and nutrient addition causes decline of bryophytes and lichens in alpine meadow and heath communitiesManuscript (preprint) (Other academic)
    Abstract [sv]

    Global change is predicted to have large and rapid impact on polar and alpine regions. Bryophytes and lichens increase their importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning at higher latitudes/altitudes. Here we report from a seven year factorial experiment with nutrient addition and warming on the abundance of bryophytes and lichens in an alpine meadow and heath community. Treatments had significant negative effect on relative change of total abundance bryophytes and lichens, the largest decline to the nutrient addition and the combined nutrient addition and warming treatments, bryophytes decreasing most in the meadow, lichens most in the heath. Nutrient addition, and the combined nutrient addition and warming brought rapid decrease in both bryophytes and lichens, while warming had a delayed negative impact. Of sixteen species that were included the statistical analyses, we found significant negative effects on seven species. We show that impact of simulated global change on bryophytes and lichens differ in in time and magnitude among treatments and plant communities. Our results underscore the importance of longer-term studies to improve the quality of climate change models, as short-term studies are poor predictors of longer-term responses of bryophytes and lichens, similar to what have been shown for vascular plants. Species-specific responses may differ in time, and this will likely cause changes in the dominance structures of bryophytes and lichens over time.

  • 6. Alatalo, Juha M.
    et al.
    Jägerbrand, Annika K.
    VTI, Swedish National Road and Transport Research Institute, Stockholm, Sweden.
    Molau, Ulf
    Testing reliability of short-term responses to predict longer-term responses of bryophytes and lichens to environmental change2015In: Ecological Indicators, ISSN 1470-160X, E-ISSN 1872-7034, Vol. 58, no Supplement C, p. 77-85Article in journal (Refereed)
    Abstract [en]

    Environmental changes are predicted to have severe and rapid impacts on polar and alpine regions. At high latitudes/altitudes, cryptogams such as bryophytes and lichens are of great importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning. This seven-year factorial experiment examined the effects of fertilizing and experimental warming on bryophyte and lichen abundance in an alpine meadow and a heath community in subarctic Sweden. The aim was to determine whether short-term responses (five years) are good predictors of longer-term responses (seven years). Fertilizing and warming had significant negative effects on total and relative abundance of bryophytes and lichens, with the largest and most rapid decline caused by fertilizing and combined fertilizing and warming. Bryophytes decreased most in the alpine meadow community, which was bryophyte-dominated, and lichens decreased most in the heath community, which was lichen-dominated. This was surprising, as the most diverse group in each community was expected to be most resistant to perturbation. Warming alone had a delayed negative impact. Of the 16 species included in statistical analyses, seven were significantly negatively affected. Overall, the impacts of simulated warming on bryophytes and lichens as a whole and on individual species differed in time and magnitude between treatments and plant communities (meadow and heath). This will likely cause changes in the dominance structures over time. These results underscore the importance of longer-term studies to improve the quality of data used in climate change models, as models based on short-term data are poor predictors of long-term responses of bryophytes and lichens.

  • 7.
    Alatalo, Juha M
    et al.
    Qatar University.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Čuchta, Peter
    Academy of Science of the Czech Republic.
    Collembola at three alpine subarctic sites resistant to twenty years of experimental warming2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 18161Article in journal (Refereed)
    Abstract [en]

    This study examined the effects of micro-scale, site and 19 and 21 years of experimental warming on Collembola in three contrasting alpine subarctic plant communities (poor heath, rich meadow, wet meadow). Unexpectedly, experimental long-term warming had no significant effect on species richness, effective number of species, total abundance or abundance of any Collembola species. There were micro-scale effects on species richness, total abundance, and abundance of 10 of 35 species identified. Site had significant effect on effective number of species, and abundance of six species, with abundance patterns differing between sites. Site and long-term warming gave non-significant trends in species richness.

    The highest species richness was observed in poor heath, but mean species richness tended to be highest in rich meadow and lowest in wet meadow. Warming showed a tendency for a negative impact on species richness. This long-term warming experiment across three contrasting sites revealed that Collembola is capable of high resistance to climate change. We demonstrated that micro-scale and site effects are the main controlling factors for Collembola abundance in high alpine subarctic environments. Thus local heterogeneity is likely important for soil fauna composition and may play a crucial role in buffering Collembola against future climate change.

  • 8.
    Alatalo, Juha M.
    et al.
    Department of Ecology and Genetics, Uppsala University, Visby, Sweden.
    Little, Chelsea, J.
    Department of Ecology and Genetics, Uppsala University, Visby, Sweden.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Molau, Ulf
    Göteborgs Universitet.
    Dominance hierarchies, diversity and species richness of vascular plants in an alpine meadow: contrasting short and medium term responses to simulated global change2014In: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 2, article id e406Article in journal (Refereed)
    Abstract [en]

    We studied the impact of simulated global change on a high alpine meadow plant community. Specifically, we examined whether short-term (5 years) responses are good predictors for medium-term (7 years) changes in the system by applying a factorial warming and nutrient manipulation to 20 plots in Latnjajaure, subarctic Sweden. Seven years of experimental warming and nutrient enhancement caused dramatic shifts in dominance hierarchies in response to the nutrient and the combined warming and nutrient enhancement treatments. Dominance hierarchies in the meadow moved from a community being dominated by cushion plants, deciduous, and evergreen shrubs to a community being dominated by grasses, sedges, and forbs. Short-term responses were shown to be inconsistent in their ability to predict medium-term responses for most functional groups, however, grasses showed a consistent and very substantial increase in response to nutrient addition over the seven years.

    The non-linear responses over time point out the importance of longer-term studies with repeated measurements to be able to better predict future changes. Forecasted changes to temperature and nutrient availability have implications for trophic interactions, and may ultimately influence the access to and palatability of the forage for grazers. Depending on what anthropogenic change will be most pronounced in the future (increase in nutrient deposits, warming, or a combination of them both), different shifts in community dominance hierarchies may occur. Generally, this study supports the productivity–diversity relationship found across arctic habitats, with community diversity peaking in mid-productivity systems and degrading as nutrient availability increases further. This is likely due the increasing competition in plant–plant interactions and the shifting dominance structure with grasses taking over the experimental plots, suggesting that global change could have high costs to biodiversity in the Arctic.

  • 9.
    Alatalo, Juha M.
    et al.
    Uppsala universitet, Växtekologi och evolution.
    Little, Chelsea J.
    Uppsala universitet, Växtekologi och evolution.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Miljö, MILJÖ.
    Molau, Ulf
    Vascular plant abundance and diversity in an alpine heath under observed and simulated global change2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 10197Article in journal (Refereed)
    Abstract [en]

    Global change is predicted to cause shifts in species distributions and biodiversity in arctic tundra. We applied factorial warming and nutrient manipulation to a nutrient and species poor alpine/arctic heath community for seven years. Vascular plant abundance in control plots increased by 31%. There were also notable changes in cover in the nutrient and combined nutrient and warming treatments, with deciduous and evergreen shrubs declining, grasses overgrowing these plots. Sedge abundance initially increased significantly with nutrient amendment and then declined, going below initial values in the combined nutrient and warming treatment. Nutrient addition resulted in a change in dominance hierarchy from deciduous shrubs to grasses. We found significant declines in vascular plant diversity and evenness in the warming treatment and a decline in diversity in the combined warming and nutrient addition treatment, while nutrient addition caused a decline in species richness. The results give some experimental support that species poor plant communities with low diversity may be more vulnerable to loss of species diversity than communities with higher initial diversity. The projected increase in nutrient deposition and warming may therefore have negative impacts on ecosystem processes, functioning and services due to loss of species diversity in an already impoverished environment.

  • 10.
    Ali, Arshad
    et al.
    East China Normal University.
    Molau, Ulf
    Göteborgs Universitet.
    Bai, Yang
    Chinese Academy of Sciences.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Alatalo, Juha M.
    Qatar University.
    Diversity-productivity dependent resistance of an alpine plant community to different climate change scenarios2016In: Ecological research, ISSN 0912-3814, E-ISSN 1440-1703, Vol. 31, no 6, p. 935-945Article in journal (Refereed)
    Abstract [en]

    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.

  • 11.
    Andreas, Seiler
    et al.
    SLU.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut och Calluna AB.
    Mörkertal i viltolycksstatistiken: resultat från enkätundersökning och analyser av olycksdata2017Report (Other academic)
    Abstract [en]

    Hidden statistics in wildlife-vehicle collision data – results from a drivers’ questionnaire and database analyses

    Among the most common causes of road accidents in Sweden are collisions with wild animals, especially ungulates. Over 50,000 ungulate accidents per year have been reported during the past 5 years and the numbers are steadily in-creasing since the 1970-ies. Despite regular campaigns, extensive investment in wildlife fencing and other preventive measures, and in contrast to declining game bag in moose and roe deer, accident statistics increase faster than what can be expected from increased traffic alone. It is obvious that wildlife-vehicle accidents in Sweden are not under control. Major contributing factors are defi-ciencies in data and uncertainty in statistics. It is well known that not all accidents are reported or show up in the official statistics, but the correction factor still used by the Swedish Transport Administration is based on over 35 years old data when traffic and wildlife conditions had been different. A better knowledge of where and when and how frequent wildlife-vehicle collisions occur is needed to more effectively plan and target mitigation actions.

    This project provides updated estimates of the hidden statistics in wildlife-vehi-cle collision data and identifies uncertainties and problems in current statistics. This was done by: i. a survey with car drivers, ii. an analysis of wildlife-related accident statistics on human injuries in the Swedish Traffic Accident Data Ac-quisition (STRADA), and iii. a comparative analysis of accident report statistics from the police and from hunters provided by the National Council on Wildlife-Vehicle Collisions (Nationella Viltolycksrådet).

    To estimate how often drivers do report and refrain from reporting wildlife-ve-hicle accidents to the police, we conducted a publicly available online-survey during Nov. 2013 to Dec. 2014 that was answered by 3981 respondents. We asked the respondents about their knowledge of and experience with wildlife-ve-hicle accidents and requested details on the most recent incident they experi-enced after 2004. More than half of all respondents (65%) reported to have been involved in wildlife-vehicle collisions at any time and around 20 % of these indi-cated that the accident was never reported to the police. About 45% of the re-spondents declared that they experienced traffic accidents with wildlife after 2004, and the proportion of non-reported incidents was estimated to between 9% (public respondents) and 19 % (control groups). We recommend therefore assuming that about 15% (± 5%) of the incidents will not be known by the police. Compared to studies from the late 1970-ies, these hidden statistics appear hence much smaller today.

    After that an incident has been reported to the police, however, there are further important sources of data loss. Depending on how the incident has been classified in the report, the records are manually transferred to secondary databases such as the traffic accident register (T-RAR). Incidents where wildlife was not the immediate cause of the accident may not be classified as wildlife-vehicle collision and thus not be found in the of-ficial police statistics. This loss has not been quantified but is estimated to be around 2%.

    Traffic accidents with human injuries (about 1.6% of all wildlife accidents) are reported to the database STRADA. Our analysis showed that on average 37% of all game-related injury accidents during 2003- 2012 was not classified as a wild-life accident and therefore probably neither was listed as such in the official police statistics.

    In most cases (74%) when an accident with wildlife is reported to the police, they notify a contracted hunter to take care of the injured animal. The hunter in turn issues a report with detailed information on the location, time and animal species. Not all of the reports (84%), however, contain complete and accurate in-formation that can be used for spatial analyses of accidents. In addition, hunt-ers’ reports seem to be biased towards larger roads and underestimate the num-ber of accidents on private and tertiary roads by about 12%.

    Technical problems in the police data system during 2012-2015 resulted in the loss of an unknown number of reported wildlife-vehicle accidents. This is why in some regions and in some years, more hunter reports were issued than police records exist. We estimate that this loss may accede 11% on average.

    In simplified terms, police statistics on wildlife-vehicle accidents during 2010 - 2015 may stand for about two-thirds of the truly occurred accidents, while hunter reports that are used in spatial analyses represent about half of the true accident frequency. However, this rule of thumb should be used cautiously as there are substantial differences in the hidden and lost statistics between the years, counties and species.

    Thus, the various shortfalls in these statistics have a significant impact on the overall estimate of wildlife-vehicle collision numbers. Depending on the data sources and on how statistics are used, different biases and data losses must be considered. Some of the causes can be easily overcome as they relate to deficien-cies in registration routines and database management. We therefore recom-mend a systematic check of the databases and improved control during registra-tion and classification of reported cases. We advocate that the different inde-pendent databases are linked through a common event ID. We also suggest de-tailed studies of how accidents are recorded and interpreted in order to better prevent future data loss.

  • 12.
    Antonson, Hans
    et al.
    Statens väg- och transportforskningsinstitut, Mobilitet, aktörer och planering, MAP.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Ahlström, Christer
    Statens väg- och transportforskningsinstitut, Samspel människa, fordon, transportsystem, MFT.
    Experiencing moose and landscape while driving: a simulator and questionnaire study2014In: Journal of Environmental Psychology, ISSN 0272-4944, E-ISSN 1522-9610, Vol. 41, p. 91-100Article in journal (Refereed)
    Abstract [en]

    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.

  • 13.
    Arvidsson, Anna K.
    et al.
    Statens väg- och transportforskningsinstitut, Drift och underhåll, DOU.
    Blomqvist, Göran
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Erlingsson, Sigurdur
    Statens väg- och transportforskningsinstitut, Väg- och banteknik, VBA.
    Hellman, Fredrik
    Statens väg- och transportforskningsinstitut, Väg- och banteknik, VBA.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Öberg, Gudrun
    Statens väg- och transportforskningsinstitut, Drift och underhåll, DOU.
    Klimatanpassning av vägkonstruktion, drift och underhåll2012Report (Other academic)
    Abstract [en]

    The global climate change is a reality and affecting society and transport systems. Climate change adaptation of transport systems will make the means of transportation more resilient and decrease the risk and magnitude of disruptions. Generally, climate change adaptations in road construction, operation and maintenance will need relatively large changes, but there is a shortage of the specific knowledge required as to what steps need to be taken, when and where, before measures can actually be implemented. Since climate change effects vary among Sweden's climatic zones, the impact of climate change on the road behavior and longevity is extremely difficult to predict. The need for winter maintenance in Sweden will generally decrease due to the warmer climate. Ploughing frequency will probably decrease as well, but preparedness should not be reduced too much since occasions with more extreme instances will increase. In order to succeed in making the road transport system resilient to climate change, we conclude that there is a need to develop more knowledge about the impact on the road infrastructure system as well as the operation and maintenance of the system including how to adapt through different types of variable and flexible climate adaptation measures and the effects of extreme weather events.

  • 14. Baruah, Gaurav
    et al.
    Molau, Ulf
    Jägerbrand, Annika K.
    Calluna AB, Nacka, Sweden.
    Alatalo, Juha M.
    Impacts of seven years of experimental warming and nutrient addition on neighbourhood species interactions and community structure in two contrasting alpine plant communities2018In: Ecological Complexity: An International Journal on Biocomplexity in the Environment and Theoretical Ecology, ISSN 1476-945X, E-ISSN 1476-9840, Vol. 33, no Supplement C, p. 31-40Article in journal (Refereed)
    Abstract [en]

    Abstract Global change is predicted to have major impacts on alpine and arctic ecosystems. Plant fitness and growth will be determined by how plants interact with each other at smaller scales. Local-scale neighbourhood interactions may be altered by environmental pertubations, which could fundamentally affect community structure. This study examined the effects of seven years of experimental warming and nutrient addition on overall changes in the community structure and patterns of interspecific interaction between neighbouring plant species in two contrasting alpine plant communities, mesic meadow and poor heath, in subarctic Sweden. We used a network approach to quantify the dissimilarity of plant interaction networks and the average number of interspecific neighbourhood interactions over time in response to different environmental perturbations. The results revealed that combined warming and nutrient addition had significant negative effects on how dissimilar plant interaction networks were over time compared with the control. Moreover, plant–plant neighbourhood interaction networks were more dissimilar over time in nutrient-poor heath than in nutrient-rich mesic meadow. In addition, nutrient addition alone and combined nutrient addition and warming significantly affected neighbourhood species interactions in both plant communities. Surprisingly, changes in interspecific neighbourhood interactions over time in both communities were very similar, suggesting that the nutrient-poor heath is as robust to experimental environmental perturbation as the mesic meadow. Comparisons of changes in neighbouring species interactions with changes in evenness and richness at the same scale, in order to determine whether diversity drove such changes in local-scale interaction patterns, provided moderate evidence that diversity was behind the changes in local-scale interspecific neighbourhood interactions. This implied that species might interact at smaller scales than those at which community measures were made. Overall, these results demonstrated that global change involving increased nutrient deposition and warming is likely to affect species interactions and alter community structure in plant communities, whether rich or poor in nutrients and species.

  • 15.
    Cornelissen, Johannes H. C.
    et al.
    Vrije Universiteit.
    Van Bodegom, Peter M.
    Vrije Universiteit.
    Aerts, Rien
    Vrije Universiteit.
    Callaghan, Terry V.
    University of Sheffield.
    Van Logtestijn, Richard S. P.
    Vrije Universiteit.
    Alatalo, Juha
    VINNOVA.
    Chapin, Stuart F.
    University of Alaska.
    Gerdol, Renato G.
    Università degli Studi di Ferrara Dipartimento delle Risorse Naturali e Cultural.
    Gudmundsson, Jon
    Agricultural University of Iceland.
    Gwynn-Jones, Dylan
    University of Wales.
    Hartley, Anne E.
    Florida International University.
    Hik, David S.
    University of Alberta.
    Hofgaard, Annika
    Norwegian Institute for Nature Research.
    Jónsdóttir, Ingibjörg S.
    Agricultural University of Iceland.
    Karlsson, Staffan
    Vetenskapsrådet.
    Klein, Julia A.
    Colorado State University.
    Laundre, Jim
    Marine Biological Labratory.
    Magnusson, Borgthor
    Icelandic Institute of Natural History.
    Michelsen, Anders
    University of Copenhagen.
    Molau, Ulf
    Göteborgs Universitet.
    Onipchenko, Vladimir G.
    Moscow State University.
    Quested, Helen M.
    Stockholms Universitet.
    Sandvik, Sylvi M.
    Agder University College.
    Schmidt, Inger K.
    Royal Veterinary and Agricultural University Denmark.
    Shaver, Gus R.
    Marine Biological Labratory.
    Solheim, Bjørn S.
    University of Tromsø.
    Soudzilovskaia, Nadejda A.
    Vrije Universiteit, Moscow State University.
    Stenström, Anna
    Länsstyrelsen Västra Götaland.
    Tolvanen, Anne
    Finnish Forest Research Institute.
    Totland, Ørjan T.
    Norwegian University of Life Sciences.
    Wada, Naoya W.
    University of Toyama.
    Welker, Jeffrey M.
    University of Alaska Anchorage.
    Zhao, Xinquan
    Chinese Academy of Sciences.
    Brancaleoni, Lisa
    Brancaleoni, Laura
    De Beus, Miranda A. H.
    Cooper, Elisabeth J.
    Dalen, Linda
    Harte, John
    Hobbie, Sarah E.
    Hoefsloot, Gerlof
    Jägerbrand, Annika K.
    Göteborg University.
    Jonasson, Sven
    Lee, John A.
    Lindblad, Karin
    Melillo, Jerry M.
    Neill, Christopher
    Press, Malcolm C.
    Rozema, Jelte
    Zielke, Matthias
    Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes2007In: Ecology Letters, ISSN 1461-023X, E-ISSN 1461-0248, Vol. 10, no 7, p. 619-627Article in journal (Refereed)
    Abstract [en]

    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.

  • 16.
    During, Heinjo J.
    et al.
    Utrecht University.
    Verduyn, Betty
    Utrecht University.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Biomechanical properties of the terrestrial mosses Pleurozium schreberi (Brid.) Mitt. and Pogonatum japonicum Sull. & Lesq. along altitudinal gradients in northern Japan2015In: Arctoa: A Journal of Briology, ISSN 0131-1379, Vol. 24, p. 375-381Article in journal (Refereed)
    Abstract [en]

    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.

  • 17.
    Folkeson, Lennart
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Genell, Anders
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    State of preparedness for climate change adaptation in operations and maintenance of transport infrastructure in eight Swedish municipalities2017Report (Other academic)
    Abstract [en]

    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. 

  • 18.
    Gren, Ing Marie
    et al.
    Department of Economics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Jägerbrand, Annika K.
    Jönköping University, School of Engineering, JTH, Civil Engineeering and Lighting Science. Calluna AB, Nacka, Sweden.
    Calculating the costs of animal-vehicle accidents involving ungulate in Sweden2019In: Transportation Research Part D: Transport and Environment, ISSN 1361-9209, E-ISSN 1879-2340, Vol. 70, p. 112-122Article in journal (Refereed)
  • 19.
    Gren, Ing-Marie
    et al.
    Sveriges Lantbruksuniversitet.
    Häggmark-Svensson, Tobias
    Sveriges Lantbruksuniversitet.
    Andersson, Hans
    Sveriges Lantbruksuniversitet.
    Jansson, Gunnar
    Sveriges Lantbruksuniversitet.
    Jägerbrand, Annika
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Using traffic data to estimate wildlife populations2015In: Journal of Bioeconomics, ISSN 1387-6996, E-ISSN 1573-6989, Vol. 18, no 1, p. 17-31Article in journal (Refereed)
    Abstract [en]

    Wildlife populations are threatened worldwide by, among others, habitat fragmentation and hunting pressure. An important impediment for the large scale, national and regional, management of the populations is the difficulty to quantify population dynamics. The purpose of this study is to present a tool for such estimations which is based on available data in several countries; traffic load and traffic accidents with wildlife. An econometric model is developed, which accounts for landscape characteristics. It is applied to wild boar in Sweden, for which data on traffic load and accidents for different counties and years are available. Landscape characteristics are introduced with direct or indirect effects on population growth. The indirect landscape model gives the best statistical performance, and the results show relatively small differences in calculated intrinsic growth rate among counties but considerable differences in predicted population developments.

  • 20.
    Gren, Ing-Marie
    et al.
    Swedish University of Agricultural Sciences.
    Jägerbrand, Annika K.
    Calluna AB.
    Costs of traffic accidents with ungulates in Sweden2017Report (Other academic)
    Abstract [en]

    Traffic accidents with ungulates pose a serious problem in many countries, and there is a need for predicting accidents and costs at a large scale for an efficient management of the accidents. Based on the assumption that traffic accidents are determined by traffic volume and ungulate population sizes, this study provides a relatively simple method for calculating and predicting costs of current and future traffic accidents with roe deer, wild boar, and moose in Sweden. A logistic population model is assumed for all ungulates, and econometric methods are used for predicting vehicle accidents with panel data on traffic accidents, traffic load, bags, hunting licenses, and landscape characteristics for each county and year during 2003-2015. The calculated total discounted cost of traffic accidents over a period of 15 years is relatively stable around 1300 million SEK per year in present value (which corresponds to 0.03% of gross domestic product in 2015), but the allocation of costs among ungulates differs. Costs of vehicle accidents with moose account for the largest share of the cost (44%), but accidents with wild boar show the most rapid increase over a 15 year period because of the estimated relatively high intrinsic growth rate and the recent establishment of this animal in several counties. The predicted costs are, however, sensitive to the assumption of future hunting pressure and traffic volume.

  • 21.
    Gustafsson, Susanne
    et al.
    Statens väg- och transportforskningsinstitut, Trafiksäkerhet, samhälle och trafikant, TST.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Grumert, Ellen
    Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Hastighetsdämpande åtgärder: en litteraturstudie med fokus på nya trafikmiljöåtgärder och ITS-orienterade lösningar2011Report (Other academic)
    Abstract [en]

    A literature survey has been conducted regarding international traffic calming measures that could have a potential use in Sweden and other Nordic countries. Focus has been on measures in new traffic environments and ITS (Intelligent Transport System) based solutions. Information has been obtained through searches in literature databases and on different homepages, as well as from contacts in networks. Initially, we describe common traffic calming measures used today in Swedish traffic environments. For example, different forms of vertical and horizontal measures, and different types of surfaces, road markings and paintings. In the case of existing ITS solutions, we mention speed reminder signs, variable message signs and Motorway Control System (MCS).

    New kinds of physical measures that have most potential for use are e.g. modifications of speed bumps and the construction of small curves that enforce lower speed. Such curvatures can be used at entrances to communities or before roundabouts.

    Different concepts of "shared space" (e.g. walking speed zones) are something that could be used more extensively, even at intersections and other locations in urban areas. In such cases, all traditional road equipment is removed and a synergy between different user groups is created, leading to lower speeds.

    Different types of road markings and paintings can be used to visually narrow the road, but also in order to create an optical illusion that makes one feel as if the speed is high. However, such measures are not fully effective during winter conditions. Applications in 3D can also be used to create the illusion of obstacles in the roadway and result in reduced speeds. It is important to consider the overall picture and to combine various measures in a correct way. This report gives some examples on how to implement speed reduction measures in communities with thoroughfares. Furthermore, we give example on how strategic approaches and policy design may help to efficiently implement different kinds of traffic calming measures.

    ITS-solutions, where a two-way communication between vehicles and between vehicles and the infrastructure is used, have gained momentum in Europe and internationally. Three possible systems that have not yet been introduced on the market are described. Most of the cooperative systems are still in a research and development phase. The potential of the systems is considered to be large, and this is also reflected in the extensive research and development investments in the area. Furthermore, ITS as a whole, i.e. cooperative systems as well as other ITS solutions is believed to have a great potential.

  • 22.
    Gustafsson, Susanne
    et al.
    Statens väg- och transportforskningsinstitut, Trafiksäkerhet, samhälle och trafikant, TST.
    Sörensen, Gunilla
    Statens väg- och transportforskningsinstitut, Trafiksäkerhet, samhälle och trafikant, TST.
    Eriksson, Olle
    Statens väg- och transportforskningsinstitut, Drift och underhåll, DOU.
    Genell, Anders
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Ljudvarningar vid vägarbetsplatser för att uppnå sänkta hastigheter: Kartläggning och praktisk utvärdering2014Report (Other academic)
    Abstract [en]

    A project has been carried out to find methods that effectively decrease drivers’ speeds at road work sites through real-time audio warnings. The project consisted of two parts. First, a survey of existing studies took place. The results show that the characteristics of a successful audio alert are female voice, direct and informative messages, an interaction between semantics and acoustics, successively increased intensity, and the dimming of secondary audio distractions. Based on the results of the survey, a practical evaluation of the potential use of audio warnings at road work sites was carried out in a VTI driver simulator. Twenty-two car drivers drove 25 kilometer on a motorway where two road works were placed on the hard shoulder. Half of the subjects were given an audio warning before the first road work and the other half prior to the second roadwork. The audio warning consisted of a sound similar to that of a GPS warning signal, followed by a female voice saying "Warning! Road work within 500 meters. Adjust the speed!". The message was sent via the car's internal speaker system. The speed reducing effect is significant and the average decrease is estimated to be 9–17 km/h greater with audio warning than without. Furthermore, there was still a small effect (0.5–3.3 km h) left of the audio alert after the road works. More results of the simulation tests are presented along with the drivers’ subjective opinions of such systems.

  • 23. Hemström, Kristian
    et al.
    Bramryd, Torleif
    Wik, Ola
    Johansson, Michael
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Ackumulering av metaller i vegetation på geotekniska askkonstruktioner2012Report (Other academic)
    Abstract [sv]

    Det övergripande syftet med denna studie var att undersöka hur användning av askor i ett långtidsperspektiv påverkar omgivande djur- och växtliv med avseende på ackumulation av metaller i ekosystem via växtupptag och exponering för betande djur. Studien innefattade en fält- och en odlingsstudie. I fältstudien studerades ackumulation av metaller och metalloider i blad från träd och buskar som självetablerat och växt under längre tid i äldre försöksuppställningar (lysimetrar) med aska. Dels i två olika åldrade slaggrus från avfallsförbränning och dels i åldrad aska från förbränning av biobränsle (grenar och toppar, GROT) och impregnerat returträ (RT), benämnd GROT/RT-aska. I odlingsstudien studerades ackumulationen av metaller och metalloider i engelskt rajgräs från askor och referensmaterial under en växtsäsong. Referensmaterial i odlingsstudien var två vanliga geotekniska material; bergkross och schaktmassa, och i fältstudien blad från träd och buskar i lysimetrarnas närområde. Samtliga studerade askor var åldrade;  5-24 år.

    Sammanfattningsvis visar studien på vikten av att ta hänsyn till damning och partikelkontaminering som exponeringsväg vid askanvändning. Vidare visar studien att åldrat slaggrus inte ger upphov till betydande förhöjda halter i blad från buskar och träd som självetablerat i sådant material eller i gräs från slaggrus som blandats med enhetsjord (50 vikt-%). Slutligen visade studien att de generella ackumuleringsfaktorer för upptag till växter som används i Naturvårdsverkets Handbok 2010:1 inte är lämpliga att använda i samband med riskbedömning av askor.

  • 24.
    Häggmark Svensson, Tobias
    et al.
    Swedish University of Agricultural Sciences, Uppsala.
    Gren, Ing-Marie
    Swedish University of Agricultural Sciences, Uppsala.
    Andersson, Hans
    Swedish University of Agricultural Sciences, Uppsala.
    Jansson, Gunnar
    Swedish University of Agricultural Sciences.
    Jägerbrand, Annika K.
    Swedish National Road and Transport Research Institute, Stockholm.
    Costs of traffic accidents with wild boar populations in Sweden2014Report (Other academic)
    Abstract [en]

    Traffic accidents with wild boar have increased rapidly over the last years in Sweden. This paper calculates and predicts costs of current and future accidents, totally and for different Swedish counties, based on estimates of wild boar populations. A logistic population model is assumed, and econometric methods are used for calculating populations with panel data on traffic accidents, traffic load, and landscape characteristics for each county. The results show an average growth rate of 0.48, which varies between 0.39 and 0.52for different counties. This, together with predictions on changes in traffic load, forms the basis for calculations of costs of traffic accidents for a 10 year period. In total, the predicted costs can increase from 60 million SEK in 2011 to 135 or 340 million SEK in 2021 in present value depending on hunting pressure. The variation in cost increases is, however, large among counties, increasing by tenfold in Stockholm and Södermanland where the wild boar populations are relatively small and by approximately 50% in counties with mature populations.

  • 25.
    Janhäll, Sara
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Genell, Anders
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Trafikinformation och miljöeffekter: beräkningar av omledningseffekter2013Report (Other academic)
    Abstract [en]

    This project aims at calculating the environmental impact of traffic with a new computational model. A list of possible measures to reduce environmental effects using traffic information is given, aiming at improving energy efficiency, air quality, noise, and environmental impact. The use of traffic information to control traffic is growing, especially in urban environments where congestion impacts trafficability, while alternative routes are available. In the road sector The Swedish Transport Administration usually informs the traveller directly, while in the rail sector information is directed to the train companies who then inform travellers/drivers. This affects the ability to manage traffic, and creates problems for the intermodal information. This report focuses on the urgent environmental impact of traffic, although a review of long-term effects are included. Only the change in traffic and driving style affects the calculations. Many environmental impacts are affected by traffic, such as air pollution, noise, greenhouse gas emissions, but also the barrier effects, light pollution, water pollution and soil disturbance in sensitive areas. Calculations with the model show how emissions are affected by driving mode, and how the population exposure is affected. The existing models are highly simplified and development in emission modeling, exposure, effects of exposure, and model implementation is essential.

  • 26.
    Janhäll, Sara
    et al.
    Statens väg- & transportforskningsinstitut (VTI).
    Jägerbrand, Annika K.
    Jönköping University, School of Engineering, JTH, Civil Engineeering and Lighting Science. Statens väg- & transportforskningsinstitut (VTI).
    Vägnära vegetation i staden – påverkan på trafiksäkerhet och luftkvalitet2019Report (Other academic)
    Abstract [sv]

    Att använda vegetation för att minska halterna av luftföroreningar i tätorter har blivit alltmer vanligt. Tidigare studier har visat att vegetationen bör placeras nära källan för att underlätta rening av luften via filtrering. Det finns också andra aspekter på hur vegetationen ska designas för att ge positiva effekter på luftkvaliteten. Då placeringen av vegetation mycket nära trafiken också kan ge effekter på trafiksäkerheten har denna studie kombinerat de nya rekommendationerna avseende luftkvalitet med en genomgång av hur vegetation behandlas i de planeringsprocesser som är aktuella för vägnära vegetation och hur vägnära vegetation påverkar trafiksäkerheten. Denna studie har genomförts främst med hjälp av litteraturstudier, både av vetenskaplig litteratur och av handledningar och annan typ av skriftligt material inom området.

    Viktiga slutsatser av studien är att vegetation behandlas på olika sätt i olika delar av planeringsprocesserna, vilket kan göra att hanteringen av vägnära vegetation ibland försvåras. Vår bedömning är att vägplanering och vegetationsplanering kan behöva integreras i fler fall.

    Avseende trafiksäkerhet finns rekommendationer om att röja den vegetation som hindrar synbarheten, både direkt och genom att skugga behövlig belysning. Det finns också anledning att hålla stamdiametrar nere för att minska risken för allvarlig skada, samt att beakta hur vegetation kan ta upp krockkrafter och minska skaderisken. Vegetationen kan också ha positiva trafiksäkerhetseffekter genom visuell eller fysisk avgränsning, skydda mot bländning eller användas som en hastighetsdämpande åtgärd.

  • 27. Jonsdottir, I.S.
    et al.
    Crittenden, P.
    Jägerbrand, Annika K.
    Göteborg University.
    Measuring growth rates in bryophytes and lichens1997In: Summary document of 8th Annual ITEX Workshop. Royal Holloway Institute for Environmental Research, 19-22 April, 1997, 1997Conference paper (Other academic)
  • 28.
    Jägerbrand, Annika
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Alatalo, Juha M.
    Uppsala Universitet.
    Kudo, Gaku
    Hokkaido University.
    Variation in responses to temperature treatments ex situ of the moss Pleurozium schreberi (Willd. ex Brid.) Mitt.originating from eight altitude sites in Hokkaido, Japan2014In: Journal of Bryology, ISSN 0373-6687, E-ISSN 1743-2820, Vol. 36, no 3, p. 209-216Article in journal (Refereed)
    Abstract [en]

    Thermal acclimatisations are important for the survival and growth of individuals and populations but seldom studied for different populations of bryophytes. The aims of this study were to (I) investigate if responses to temperature treatments were independent of the site sampled or if the intra- and interpopulation variation in responses were larger than the responses to the temperature treatments (control, press, and pulse), and to (II) examine if experimental responses varied, depending on the sampled sites.

    We collected samples of the circumpolar bryophyte species, Pleurozium schreberi (Willd. ex Brid.) Mitt., originating from eight altitude sites on Mt. Oakan in Hokkaido, Japan, and exposed them to three different temperature treatments ex situ for four weeks. Thermal acclimatisation was estimated by measuring responses in growth length increase, biomass increase, number of branches, and the maximum quantum yield of PS II (Fv/Fm). We found that responses to temperature treatments were dependent of the site sampled, and that differences were most pronounced in the length increase. Results also shows that the responses to experimental treatments may differ between sites. Our results therefore raise important concerns regarding the general validity of both ex situ and in situ experiments when performed on a single or a limited number of sites.

  • 29.
    Jägerbrand, Annika K.
    Göteborg University.
    A new method for assessing dispersal and colonization of bryophytes2007In: Journal of Bryology, ISSN 0373-6687, E-ISSN 1743-2820, Vol. 29, no 2, p. 133-134Article in journal (Refereed)
  • 30.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Anpassning av vägmiljö och vegetation som åtgärd mot viltolyckor2012Report (Other academic)
    Abstract [en]

    Wildlife accidents are a global problem that causes human fatalities as well as physical and economic damage. Current preventive measures do not seem sufficient enough to achieve a reduction in wildlife accidents. The road environment may be modified so as to reduce the attractiveness of resources in the road area. Modifications may be directed towards the maintenance (e.g. adjustment of mowing practices) or the structure or composition of the vegetation. This report presents an overview of the current knowledge about how the road area, and to some extent also the adjacent areas, can be made less attractive to wildlife through road environment and vegetation changes. The report deals with relationships between wildlife presence/wildlife accidents and the surrounding environment as well as road operation and maintenance. Studies of wildlife collisions and the surrounding environment reveal complex relationships between wildlife collisions and landscape features (e.g. forest or open landscape), species and/or habitat diversity. How crucial these characteristics are for wildlife collisions largely depends on which game animals are studied. Mowing and clear-cutting activities, as well as adjacent land use may influence the roadside attraction for wildlife, sometimes in unknown ways. The list of plants that should be unattractive to grazing should be evaluated and developed further.

  • 31.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Dead or alive? Testing the use of C:N ratios and chlorophyll fluorescence in vertical shoot profiles to determine depth of vitality and point of senescence in populations of bryophytes2015In: Lindbergia, ISSN 0105-0761, E-ISSN 2001-5909, Vol. 38, p. 4-13Article in journal (Refereed)
    Abstract [en]

    Bryophytes with indeterminate growth rarely exhibit clearly identifiable modules or age segments, but can be vertically divided into different physiologically active zones, since physiological activity normally declines vertically along the shoot profile depth. The aim of this study was to investigate whether it is possible to use C:N ratios (C/N)and/or parameters from chlorophyll fluorescence measurements (e.g. Fv/Fm, Fm or qN)to determine if bryophyte tissue is alive, senescent or dead, and at what distance along the shoot segment profile the moss tissue cease to live. Variation in C:N ratios and chlorophyll fluorescence between sites was also examined. This study shows that it is possible to separate alive, senescing and dead parts of the moss shoots in Pleurozium schreberi, and that chlorophyll fluorescence is a good method to use, whereas C/N varies between sites and species (for Hylcomium splendens and Racomitrium lanuginosum)and does not seem to reflect physiological activity to the same degree.

  • 32.
    Jägerbrand, Annika K.
    Hokkaido University.
    Effects of an in situ temperature increase on the short-term growth of arctic-alpine bryophytes2007In: Lindbergia, ISSN 0105-0761, E-ISSN 2001-5909, Vol. 32, no 3, p. 82-87Article in journal (Refereed)
    Abstract [en]

    This study examined the short-term growth responses to a temperature increase in situ of three bryophytes species of different genera. Temperatures were enhanced by the use of open-top chambers at Latnjajaure, a subarctic-alpine site in northernmost Sweden. Growth was measured during the growing season of 1995, using the tied-thread method for Aulacomnium turgidum, the cranked-wire method for Sphagnum teres, and the shoot-transplanting method for Tomentypnum nitens. Temperature enhancement significantly increased the growth in length of Sphagnum teres while no significant effects were found for the other two species. One possible reason for this is that Sphagnum teres had more water available, while the other two species could not respond to increased temperature due to constraints of water availability. 

  • 33.
    Jägerbrand, Annika K.
    Jönköping University, School of Engineering, JTH, Civil Engineeering and Lighting Science.
    Evaluation between energy efficiency, ecological impactand the compliance of regulations of road lighting2019In: Proceedings of the 29th Session of the CIE: Washington D.C., USA, June 14 – 22, 2019, Volume 1 – Part 2, Vienna: The International Commission on Illumination, 2019, Vol. 1, p. 1720-1728Conference paper (Other academic)
    Abstract [en]

    Road lighting causes unwanted ecological impact on species and habitats where species may be protected and/or light-sensitive. Yet, there is very little information available on how roadlighting should be ecologically designed while simultaneously considering energy efficiency and the regulations needed for safety reasons. The aim of this study was study designs of different dimensions regarding energy efficiency, ecological impact and the compliance with regulations for traffic safety. By using DIALux evo simulations with four different LED luminaires, different scenarios of road lighting designs (pole distance of 10m, 25m and 40m, and pole heights of 3m, 5m, and 8m) on a 7m wide road was evaluated. Ecological thresholds of 1 lux and 0.1 lux are possible to get below at distances from the road edge between 5–11m, and 8.5–20m, respectively. Results are discussed from the perspectives of increased demand on energy efficiency on road lighting.

  • 34.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Kollisioner och olyckor med rådjur i Sverige under 10 år (2003–2012): variation i tid, geografi och kostnader2014Report (Other academic)
    Abstract [en]

    The goal for this project was to create a 10-year overview of the number of deer collisions in Sweden and accidents variation in time, geography and cost, both in terms of property damage and personal injuries. Accident statistics were gathered from NVR (National Wildlife Accident Council, data on collisions), Strada (fatalities and injuries in Swedish Traffic Accident Data Acquisition) and Ofelia (collisions at railway). The results show that the number of deer collisions has increased over the 10-year period and that the increase has been much greater in the northernmost counties and Gotland. The number of deer collisions is higher during the early summer (May–June) and winter (October–December), whereas the number of fatalities and injury accidents is highest during the summer. The number of deer collisions varies during the day, but most accidents occur in the morning and evening for both property damage and personal injury accidents. For fatalities in accidents with roe deer, there are more than twice as many compared to the officially reported numbers, and the number of serious injuries is 177% higher than the official records. It is likely that the official statistics are also underestimating the number of fatalities and injuries from wildlife accidents caused by moose, deer and wild boar. This study shows that the total cost of roe deer collisions and accidents in 2012 exceeds 1 billion SEK, of which approximately 70% account for the cost of property damage.

  • 35.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    LED (Light-Emitting Diode) road lighting in practice: An evaluation of compliance with regulations and improvements for further energy savings2016In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 9, no 5, article id 357Article in journal (Refereed)
    Abstract [en]

    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.

  • 36.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    LED och ekologiska effekter2015In: Ceebel Nyhetsbrev, Vol. 1, p. 1-3Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    LED har olika typer av ekologisk påverkan och kan i vissa fall leda till större effekter än traditionellt använd belysning. Samtidigt har LED potential att kunna utvecklas till en ekologisk neutral belysning. Det finns en rad olika saker man kan tänka på vid inköp av LED-lampor för att minimera ekologisk påverkan, såsom låg effektnivå, använda dimringsteknik, undvika oönskad ljusspridning och att försöka undvika lampor som har höga nivåer av våglängder under 500 nm.

  • 37.
    Jägerbrand, Annika K.
    Jönköping University, School of Engineering, JTH, Civil Engineeering and Lighting Science. Calluna AB, Linköping.
    LED-belysningens effekter på djur och natur med rekommendationer: Fokus på nordiska förhållanden och känsliga arter och grupper2018Report (Other academic)
  • 38.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    New Framework of Sustainable Indicators for Outdoor LED (Light Emitting Diodes) Lighting and SSL (Solid State Lighting)2015In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 7, no 1, p. 1028-1063Article in journal (Refereed)
    Abstract [en]

    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.

  • 39.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Ny vägbelysning: hur väljer man & hur miljövänlig är den?2014In: REV bulletinen, Vol. 1, p. 16-17Article in journal (Other (popular science, discussion, etc.))
  • 40.
    Jägerbrand, Annika K.
    Botanical Institute, Göteborg University, Göteborg, Sweden .
    Patterns of species richness and vegetative performance in heath ecosystems at Thingvellir, Southwest Iceland2004In: Icelandic Agricultural Sciences, ISSN 1670-567X, Vol. 16-17, p. 29-38Article in journal (Refereed)
    Abstract [en]

    The Racomitrium lanuginosum (Hedw.) Brid. moss heath is a unique environment and is of great importance for co-occurring established vascular plants. A thick moss carpet can prevent or restrict the growth of vascular plants as they are exposed to more unfavourable growth conditions, but the effect on species richness and abundance is less known. To investigate the negative effects of a well-developed moss carpet on established vascular plants, patterns of species richness, shoot density, and number of leaves (Carex bigelowii Schwein. and Thalictrum alpinum L.) were studied in two different vegetation types, Racomitrium lanuginosum moss heath, and dwarf shrub heath in Þingvellir National Park, Southwest Iceland.

    Species richness was higher in dwarf shrub heath and increased proportionally with the size of the shrub patches. Total species richness and plant functional dominance did not differ between vegetation types. There were no differences found in shoot density, percentage of flowering and juveniles, number of leaves in Carex bigelowii, or shoot density, flowering percentage or number of leaves in Thalictrum alpinum between the vegetation types. However, leaf length of Carex bigelowii was higher in the dwarf shrubs heath, indicating more favourable growth conditions, shade or shelter effects. It is possible that translocation is taking place between the shoots of the clonal vascular plants in this study so that the plants themselves are counteracting unfavourable effects in the different vegetation types. The effect of global climatic change on moss heaths in Iceland is briefly discussed.

  • 41.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Trafiksäkerhets- och trygghetsaspekter i samspelet mellan gatumiljöns utformning och en mer energieffektiv belysning2014Report (Other academic)
    Abstract [en]

    The project's aim was to study the traffic safety aspects of new lights and the interaction with the street environment for pedestrians and cyclists. This project investigated the lighting conditions, effects on cyclists, and the interactions between lighting, traffic safety, street environmental conditions and/or other effects such as perceptions of safety for three different light sources (mercury vapour 125W, ceramic metal halide 70W and LED 25W) located in about the same type of street environment on a pedestrian and bicycle path on Kungsholms strand in Stockholm. Results show that the energy consumption of the LED lighting is 28% of the traditional mercury vapour lighting and 49% of ceramic metal halide lighting. This study shows that it is possible to obtain sufficient uniformity levels with LED lighting but that the levels are dependent on the luminaire design, pole design and the number of poles per meter road (in this study the pole spacing was 15.3 m). This study demonstrated no difference in cycle speed for LED lighting between daylight and darkness, or between different types of lighting. It worked well to perform analysis of perception of safety aspects based on simple estimates (through analysis of digital photographs). For example, perceptions of visibility corresponds very well with the measured uniformity.

  • 42.
    Jägerbrand, Annika K.
    Statens väg- och transportforskningsinstitut, Miljö och trafikanalys, MTA.
    Träds inverkan på belysningseffekt på gång- och cykelvägar2011Report (Other academic)
    Abstract [en]

    Trees and vegetation in the street environment are important components of urban areas and they increase the environmental quality in cities. The purpose of this study was to examine the influence of trees on shade effects (illuminance and spectral distribution) in pedestrian and bicycle paths by quantifying the reduction of streetlight caused by tree intrusion in order to give recommendations for the management and maintenance of trees in the street environment. Measurements of the shading were tree intrusion and tree area as well as changes in R/FR. R/FR is a measurement on how shade from vegetation affects the spectral distribution. The results show that any type of intruding vegetation into the sidewalk area has a potential blocking effect on the illuminance and that the effect increased the more the trees are infringing. Tree shadow caused the illuminance to drop between 27-77%. Current guidelines for free height above pedestrian zones, bicycle roads and driving lanes are consequently not high enough to prevent shade effects by trees. The free height of vegetation and trees should be as high as the lighting pole in order to avoid light reductions due to tree intrusion.

  • 43. Jägerbrand, Annika K.
    et al.
    Alatalo, Juha M.
    Effects of human trampling on abundance and diversity of vascular plants, bryophytes and lichens in alpine heath vegetation, Northern Sweden2015In: Springer Series in Chemical Physics, ISSN 0172-6218, E-ISSN 2193-1801, Vol. 4, no 1Article in journal (Refereed)
    Abstract [en]

    This study investigated the effects of human trampling on cover, diversity and species richness in an alpine heath ecosystem in northern Sweden. We tested the hypothesis that proximity to trails decreases plant cover, diversity and species richness of the canopy and the understory. We found a significant decrease in plant cover with proximity to the trail for the understory, but not for the canopy level, and significant decreases in the abundance of deciduous shrubs in the canopy layer and lichens in the understory. Proximity also had a significant negative impact on species richness of lichens. However, there were no significant changes in species richness, diversity or evenness of distribution in the canopy or understory with proximity to the trail. While not significant, liverworts, acrocarpous and pleurocarpous bryophytes tended to have contrasting abundance patterns with differing proximity to the trail, indicating that trampling may cause shifts in dominance hierarchies of different groups of bryophytes. Due to the decrease in understory cover, the abundance of litter, rock and soil increased with proximity to the trail. These results demonstrate that low-frequency human trampling in alpine heaths over long periods can have major negative impacts on lichen abundance and species richness. To our knowledge, this is the first study to demonstrate that trampling can decrease species richness of lichens. It emphasises the importance of including species-level data on non-vascular plants when conducting studies in alpine or tundra ecosystems, since they often make up the majority of species and play a significant role in ecosystem functioning and response in many of these extreme environments.

  • 44. Jägerbrand, Annika K.
    et al.
    Alatalo, Juha M.
    Uppsala universitet, Växtekologi och evolution.
    Effects of human trampling on abundance and diversity of vascular plants, bryophytes and lichens in alpine heath vegetation, Northern Sweden2015In: Springer Series in Chemical Physics, ISSN 0172-6218, E-ISSN 2193-1801, Vol. 4, article id 95Article in journal (Refereed)
    Abstract [en]

    This study investigated the effects of human trampling on cover, diversity and species richness in an alpine heath ecosystem in northern Sweden. We tested the hypothesis that proximity to trails decreases plant cover, diversity and species richness of the canopy and the understory. We found a significant decrease in plant cover with proximity to the trail for the understory, but not for the canopy level, and significant decreases in the abundance of deciduous shrubs in the canopy layer and lichens in the understory. Proximity also had a significant negative impact on species richness of lichens. However, there were no significant changes in species richness, diversity or evenness of distribution in the canopy or understory with proximity to the trail. While not significant, liverworts, acrocarpous and pleurocarpous bryophytes tended to have contrasting abundance patterns with differing proximity to the trail, indicating that trampling may cause shifts in dominance hierarchies of different groups of bryophytes. Due to the decrease in understory cover, the abundance of litter, rock and soil increased with proximity to the trail. These results demonstrate that low-frequency human trampling in alpine heaths over long periods can have major negative impacts on lichen abundance and species richness. To our knowledge, this is the first study to demonstrate that trampling can decrease species richness of lichens. It emphasises the importance of including species-level data on non-vascular plants when conducting studies in alpine or tundra ecosystems, since they often make up the majority of species and play a significant role in ecosystem functioning and response in many of these extreme environments.

  • 45.
    Jägerbrand, Annika K.
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Alatalo, Juha M.
    Campus Gotland, Uppsala Universitet.
    Native roadside vegetation that enances soil erosion control in boreal Scandinavia2014In: Environments, ISSN 2076-3298, Vol. 1, p. 31-41Article in journal (Refereed)
    Abstract [en]

    This study focused on identifying vegetation characteristics associated with erosion control at nine roadside sites in mid-West Sweden. A number of vegetation characteristics such as cover, diversity, plant functional type, biomass and plant community structure were included. Significant difference in cover between eroded and non-eroded sub-sites was found in evergreen shrubs, total cover, and total above ground biomass. Thus, our results support the use of shrubs in order to stabilize vegetation and minimize erosion along roadsides. However, shrubs are disfavored by several natural and human imposed factors. This could have several impacts on the long-term management of roadsides in boreal regions. By both choosing and applying active management that supports native evergreen shrubs in boreal regions, several positive effects could be achieved along roadsides, such as lower erosion rate and secured long-term vegetation cover. This could also lead to lower costs for roadside maintenance as lower erosion rates would require less frequent stabilizing treatments and mowing could be kept to a minimum in order not to disfavor shrubs.                                                                                                             

  • 46.
    Jägerbrand, Annika K.
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Alatalo, Juha M
    Jönköpings Universitet.
    Chrimes, Dillon
    University of Tokyo.
    Molau, Ulf
    Göteborgs Universitet.
    Plant community responses to 5 years of simulated climate change in meadow and heath ecosystems at a subarctic-alpine site2009In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 161, no 3, p. 601-610Article in journal (Refereed)
    Abstract [en]

    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.

  • 47.
    Jägerbrand, Annika K.
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Antonson, Hans
    Statens väg- och transportforskningsinstitut, Mobilitet, aktörer och planering, MAP.
    Driving behaviour responses to a moose encounter, automatic speed camera, wildlife warning sign and radio message determined in a factorial simulator study2016In: Accident Analysis and Prevention, ISSN 0001-4575, E-ISSN 1879-2057, Vol. 86, p. 229-238Article in journal (Refereed)
    Abstract [en]

    In a driving simulator study, driving behaviour responses (speed and deceleration) to encountering a moose, automatic speed camera, wildlife warning sign and radio message, with or without a wildlife fence and in dense forest or open landscape, were analysed. The study consisted of a factorial experiment that examined responses to factors singly and in combination over 9-km road stretches driven eight times by 25 participants (10 men, 15 women). The aims were to: determine the most effective animal–vehicle collision (AVC) countermeasures in reducing vehicle speed and test whether these are more effective in combination for reducing vehicle speed; identify the most effective countermeasures on encountering moose; and determine whether the driving responses to AVC countermeasures are affected by the presence of wildlife fences and landscape characteristics. The AVC countermeasures that proved most effective in reducing vehicle speed were a wildlife warning sign and radio message, while automatic speed cameras had a speed-increasing effect. There were no statistically significant interactions between different countermeasures and moose encounters. However, there was a tendency for a stronger speed-reducing effect from the radio message warning and from a combination of a radio message and wildlife warning sign in velocity profiles covering longer driving distances than the statistical tests. Encountering a moose during the drive had the overall strongest speed-reducing effect and gave the strongest deceleration, indicating that moose decoys or moose artwork might be useful as speed-reducing countermeasures. Furthermore, drivers reduced speed earlier on encountering a moose in open landscape and had lower velocity when driving past it. The presence of a wildlife fence on encountering the moose resulted in smaller deceleration.

  • 48.
    Jägerbrand, Annika K.
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Antonson, Hans
    Statens väg- och transportforskningsinstitut, Mobilitet, aktörer och planering, MAP.
    Kan viltolyckor förebyggas av körsätt?: En körsimulatorstudie utförd av VTI. Slutrapport till Viltvårdsfonden, projekt nr 802-0224-092013Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    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.

  • 49.
    Jägerbrand, Annika K.
    et al.
    Jönköping University, School of Engineering, JTH, Civil Engineeering and Lighting Science. Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Antonson, Hans
    Department of Human Geography, Lund University, Sweden.
    Ahlström, Christer H.G.
    Swedish National Road and Transport Research Institute (VTI), Linköping (VTI), Sweden.
    Speed reduction effects over distance of animal-vehicle collision countermeasures – a driving simulator study2018In: European Transport Research Review, ISSN 1867-0717, E-ISSN 1866-8887, Vol. 10, no 2, article id 40Article in journal (Refereed)
    Abstract [en]

    Purpose: This study examined if speed reduction effects from animal-vehicle collision (AVC) countermeasures are merely local or do extend to a wider area, and what implications the results have on road planning practice regarding AVCs.

    Methods: Twenty-five drivers drove repeatedly on a 9-km long road stretch in a high-fidelity driving simulator. The development of vehicle speed in the surrounding of an automatic speed camera, a wildlife warning sign and a radio message, were investigated in a full factorial within-subject experiment. The factors wildlife fence (with/without) and forest (dense/open landscape) were also included.

    Results: The radio warning message had the largest influence on vehicle speed with a speed reduction of 8 km/h that lasted beyond 1 km and 2 km after the implementation. Eighty-eight per cent of the drivers reported being made extra aware of AVC due to the radio message, which was also associated with stress, insecurity and unsafety. The warning sign reduced vehicle speed by 1.5 km/h, but speed reductions were not significantly reduced 1 km after the implementation. Only 8 % of the drivers felt insecure/unsafe after passing the wildlife warning sign, explaining its limited impact on speed. There were no main effects of the automatic speed camera on vehicle speed at longer distances after implementation.

    Conclusions: We recommend that AVC countermeasures should be of various design, occur at various segments along the road, and preferably be adaptive and geo-localized to minimize habituation effects on drivers. 

  • 50.
    Jägerbrand, Annika K.
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Björk, Robert
    Göteborgs Universitet.
    Callaghan, Terry
    Seppelt, Rod
    Effects of climate change on tundra bryophytes2011In: Bryophyte ecology and climate change / [ed] Nancy Slack, Zoltan Tuba, and Lloyd Stark, Cambridge University Press, 2011, 1, p. 211-236Chapter in book (Other academic)
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