| 1. |
- Cornelissen, Johannes H C, et al.
(författare)
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Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes
- 2007
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 10:7, s. 619-627
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Tidskriftsartikel (refereegranskat)abstract
- Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition. Here, we present the first quantitative analysis of the major climate-change-related drivers of litter decomposition rates in cold northern biomes worldwide.Leaf litters collected from the predominant species in 33 global change manipulation experiments in circum-arctic-alpine ecosystems were incubated simultaneously in two contrasting arctic life zones. We demonstrate that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species. Specifically, the ongoing warming-induced expansion of shrubs with recalcitrant leaf litter across cold biomes would constitute a negative feedback to global warming. Depending on the strength of other (previously reported) positive feedbacks of shrub expansion on soil carbon turnover, this may partly counteract direct warming enhancement of litter decomposition.
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| 2. |
- Komatsu, Kimberly J., et al.
(författare)
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Global change effects on plant communities are magnified by time and the number of global change factors imposed
- 2019
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 116:36, s. 17867-17873
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Tidskriftsartikel (refereegranskat)abstract
- Accurate prediction of community responses to global change drivers (GCDs) is critical given the effects of biodiversity on ecosystem services. There is consensus that human activities are driving species extinctions at the global scale, but debate remains over whether GCDs are systematically altering local communities worldwide. Across 105 experiments that included over 400 experimental manipulations, we found evidence for a lagged response of herbaceous plant communities to GCDs caused by shifts in the identities and relative abundances of species, often without a corresponding difference in species richness. These results provide evidence that community responses are pervasive across a wide variety of GCDs on long-term temporal scales and that these responses increase in strength when multiple GCDs are simultaneously imposed.Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.
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| 3. |
- Alatalo, Juha M., et al.
(författare)
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Bryophyte cover and richness decline after 18 years of experimental warming in Alpine Sweden
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- 1. Bryophytes in the Arctic and Alpine regions are important in terms of biodiversity, cover and biomass. However, climate change and widespread shrubification of alpine and arctic tundra is predicted to increase in the future, with potentially large impacts on bryophyte communities.2. We studies the impact of 18 years of experimental warming with open top chambers (OTCs) on bryophyte cover, richness and diversity in an alpine mesic meadow and a heath plant community in Northern Sweden. In addition we investigated the relationship between deciduous shrubs and bryophytes.3. Cover and richness of bryophytes both declined due to long-term warming, while diversity did not show any significant responses. After 18 years, bryophyte cover had decreased by 71% and 26 in the heath and meadow, while richness declined by 39% and 26%, respectively.4. Synthesis. Decline in total bryophyte cover in both communities in response to long-term warming was driven by a general decline in many species, with only two individual species showing significant declines. Although most of the species included in the individual analyses did not show any detectable changes, the cumulative change in all species was significant. In addition, species loss was slower than the general decline in bryophyte abundance. As hypothesized, we found significant negative relationship between deciduous shrub cover and bryophyte cover, but not bryophyte richness, in both plant communities. This is likely due to a more delayed decline in species richness compared to abundance, similar to what was observed in response to long-term warming.
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| 4. |
- Alatalo, J. M., et al.
(författare)
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Bryophyte cover and richness decline after 18 years of experimental warming in alpine Sweden
- 2020
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Ingår i: Aob Plants. - Oxford : Oxford University Press (OUP). - 2041-2851. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is expected to affect alpine and Arctic tundra communities. Most previous long-term studies have focused on impacts on vascular plants, this study examined impacts of long-term warming on bryophyte communities. Experimental warming with open-top chambers (OTCs) was applied for 18 years to a mesic meadow and a dry heath alpine plant community. Species abundance was measured in 1995, 1999, 2001 and 2013. Species composition changed significantly from original communities in the heath, but remained similar in mesic meadow. Experimental warming increased beta diversity in the heath. Bryophyte cover and species richness both declined with long-term warming, while Simpson diversity showed no significant responses. Over the 18-year period, bryophyte cover in warmed plots decreased from 43 % to 11 % in heath and from 68 % to 35 % in meadow (75 % and 48 % decline, respectively, in original cover), while richness declined by 39 % and 26 %, respectively. Importantly, the decline in cover and richness first emerged after 7 years. Warming caused significant increase in litter in both plant communities. Deciduous shrub and litter cover had negative impact on bryophyte cover. We show that bryophyte species do not respond similarly to climate change. Total bryophyte cover declined in both heath and mesic meadow under experimental long-term warming (by 1.5-3 degrees C), driven by general declines in many species. Principal response curve, cover and richness results suggested that bryophytes in alpine heath are more susceptible to warming than in meadow, supporting the suggestion that bryophytes may be less resistant in drier environments than in wetter habitats. Species loss was slower than the decline in bryophyte abundance, and diversity remained similar in both communities. Increased deciduous shrub and litter cover led to decline in bryophyte cover. The non-linear response to warming over time underlines the importance of long-term experiments and monitoring.
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| 5. |
- Alatalo, Juha M., et al.
(författare)
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Climate change and climatic events: community-, functional- and species-level responses of bryophytes and lichens to constant, stepwise, and pulse experimental warming in an alpine tundra
- 2014
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Ingår i: Alpine Botany. - : Springer Science and Business Media LLC. - 1664-2201 .- 1664-221X. ; 124:2, s. 81-91
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally imposed three different kinds of warming scenarios over 3 years on an alpine meadow community to identify the differential effects of climate warming and extreme climatic events on the abundance and biomass of bryophytes and lichens. Treatments consisted of (a) a constant level of warming with open top chambers (an average temperature increase of 1.87 A degrees C), (b) a yearly stepwise increase of warming (average temperature increases of 1.0; 1.87 and 3.54 A degrees C, consecutively), and (c) a pulse warming, i.e., a single first year pulse event of warming (average temperature increase of 3.54 A degrees C only during the first year). To our knowledge, this is the first climate change study that attempts to distinguish between the effects of constant, stepwise and pulse warming on bryophyte and lichen communities. We hypothesised that pulse warming would have a significant short-term effect compared to the other warming treatments, and that stepwise warming would have a significant mid-term effect compared to the other warming treatments. Acrocarpous bryophytes as a group increased in abundance and biomass to the short-term effect of pulse warming. We found no significant effects of mid-term (third-year) stepwise warming. However, one pleurocarpous bryophyte species, Tomentypnum nitens, generally increased in abundance during the warm year 1997 but decreased in control plots and in response to the stepwise warming treatment. Three years of experimental warming (all treatments as a group) did have a significant impact at the community level, yet changes in abundance did not translate into significant changes in the dominance hierarchies at the functional level (for acrocarpous bryophytes, pleurocarpous bryophytes, Sphagnum or lichens), or in significant changes in other bryophyte or lichen species. The results suggest that bryophytes and lichens, both at the functional group and species level, to a large extent are resistant to the different climate change warming simulations that were applied.
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| 6. |
- Alatalo, Juha M, et al.
(författare)
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Collembola at three alpine subarctic sites resistant to twenty years of experimental warming
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Alatalo, J. M., et al.
(författare)
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Impacts of different climate change regimes and extreme climatic events on an alpine meadow community
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Climate variability is expected to increase in future but there exist very few experimental studies that apply different warming regimes on plant communities over several years. We studied an alpine meadow community under three warming regimes over three years. Treatments consisted of (a) a constant level of warming with open-top chambers (ca. 1.9 degrees C above ambient), (b) yearly stepwise increases in warming (increases of ca. 1.0, 1.9 and 3.5 degrees C), and (c) pulse warming, a single first-year pulse event of warming (increase of ca. 3.5 degrees C). Pulse warming and stepwise warming was hypothesised to cause distinct first-year and third-year effects, respectively. We found support for both hypotheses; however, the responses varied among measurement levels (whole community, canopy, bottom layer, and plant functional groups), treatments, and time. Our study revealed complex responses of the alpine plant community to the different experimentally imposed climate warming regimes. Plant cover, height and biomass frequently responded distinctly to the constant level of warming, the stepwise increase in warming and the extreme pulse-warming event. Notably, we found that stepwise warming had an accumulating effect on biomass, the responses to the different warming regimes varied among functional groups, and the short-term perturbations had negative effect on species richness and diversity
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| 8. |
- Alatalo, Juha M., et al.
(författare)
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Impacts of twenty years of experimental warming on soil carbon, nitrogen, moisture and soil mites across alpine/subarctic tundra communities
- 2017
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Ingår i: Scientific Reports. - : Macmillan Publishers Ltd.. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 9. |
- Alatalo, J. M., et al.
(författare)
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Responses of lichen communities to 18 years of natural and experimental warming
- 2017
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Ingår i: Annals of Botany. - : Oxford University Press (OUP). - 0305-7364 .- 1095-8290. ; 120:1, s. 159-170
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Tidskriftsartikel (refereegranskat)abstract
- 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 degrees 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.
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| 10. |
- Ali, A., et al.
(författare)
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Diversity-productivity dependent resistance of an alpine plant community to different climate change scenarios
- 2016
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Ingår i: Ecological Research. - : Wiley. - 0912-3814 .- 1440-1703. ; 31:6, s. 935-945
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Tidskriftsartikel (refereegranskat)abstract
- Here we report from a experiment imposing different warming scenarios [control with ambient temperature, constant level of moderate warming for 3 years, stepwise increase in warming for 3 years, and one season of high level warming (pulse) simulating an extreme summer event] on an alpine ecosystem to study the impact on species diversity-biomass relationship, and community resistance in terms of biomass production. Multiple linear mixed models indicate that experimental years had stronger influence on biomass than warming scenarios and species diversity. Species diversity and biomass had almost humpback relationships under different warming scenarios over different experimental years. There was generally a negative diversity-biomass relationship, implying that a positive diversity-biomass relationship was not the case. The application of different warming scenarios did not change this tendency. The change in community resistance to all warming scenarios was generally negatively correlated with increasing species diversity, the strength of the correlation varying both between treatments and between years within treatments. The strong effect of experimental years was consistent with the notion that niche complementarity effects increase over time, and hence, higher biomass productivity over experimental years. The strongest negative relationship was found in the first year of the pulse treatment, indicating that the community had weak resistance to an extreme event of one season of abnormally warm climate. Biomass production started recovering during the two subsequent years. Contrasting biomass-related resistance emerged in the different treatments, indicating that micro sites within the same plant community may differ in their resistance to different warming scenarios.
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| 11. |
- Andreas, Seiler, et al.
(författare)
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Mörkertal i viltolycksstatistiken : resultat från enkätundersökning och analyser av olycksdata
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En av de vanligaste orsakerna till vägtrafikolyckor är påkörning av vilda djur, i synnerhet klövdjur. Över 45 000 viltolyckor per år registrerades under de sen-aste 5 åren och antalen ökar stadigt. Trots upprepade informationskampanjer, omfattande investering i viltstängsel och andra förebyggande åtgärder och i kon-trast till avskjutningsstatistik för älg och rådjur, så ökar olyckstalen i snabbare takt än vad som kan förväntas på grund av ökat trafikarbete och större fordons-flotta. Det är tydligt att viltolycksproblematiken i Sverige inte är under kontroll. En bidragande faktor är att inte alla inträffade olycksfall rapporteras och inte alla rapporterade händelser återges av den officiella statistiken. Uppräknings-faktorerna som Trafikverket använder i sina Effektberäkningar vid Väganalyser (EVA-kalkyler) är utdaterade och utgår från effektsamband som troligtvis inte längre är aktuella. För att planera effektiva och riktade åtgärder behövs bättre kunskap om var, när och hur ofta viltolyckor inträffar.Föreliggande projekt avser att uppdatera kunskaperna om mörkertalet i rappor-teringen av viltolyckor på väg och belysa andra bortfall i statistiken. Målsätt-ningen är att ta fram ett uppdaterat underlag (Uppräkningsfaktorer) för använd-ning i effektberäkningar vid väganalyser samt undersöka kvarstående utred-ningsbehov och eventuella förbättringsmöjligheter som kan leda till en bättre uppskattning av konflikten mellan vilt och vägtrafik. Projektet omfattar tre delstudier: enkätundersökning med bilförare, analys av viltrelaterade personskadeolyckor i STRADA (d.v.s. Swedish Traffic Accident Data Acquisition) samt en jämförande analys av olycksrapporter från polisens och eftersöksjägarnas inrapportering i viltolycksstatistiken tillgänglig hos NVR (Nationella Viltolycksrådet).En enkätstudie via internet (på domänen www.viltochtrafik.se) genomfördes för att undersöka storleken på mörkertalet i rapportering av viltolyckor från bilfö-rare till polis. Enkäten var tillgänglig för allmänheten online under perioden 2013-10-31 till 2014-12-31 och besvarades av 3981 respondenter. Vi ställde frå-gor kring kunskaper om och erfarenheter med viltolyckor och bad om mer detal-jerade uppgifter om den incidenten som inträffade för respondenterna efter 2004. Mer än hälften av alla respondenter (65 %) har varit med om en klövvilt-olycka någon gång och runt 20 % av dessa angav att olyckan troligen aldrig rap-porterats till polisens kännedom. Drygt 45 % av respondenterna angav att de va-rit med om viltolyckor efter år 2004 och mörkertalet uppskattades till mellan 9 % och 19 %. Vi rekommenderar att det schablonmässiga mörkertalet för klövvilt (oavsett art) bör vara 15 % (±5 %). Våra resultat visar att mörkertalet i rapporte-ringen från bilist till polisen har närmare halverats sedan 1970-talet. Efter att en olycka anmälts till polisen finns risk för ytterligare bortfall i statisti-ken. Inkommande polisanmälningar överförs manuellt till olika databaser, bero-ende på hur händelsen klassificeras. Olyckor där viltet inte utgjorde den omedel-bara orsaken till skadan klassas inte som viltolycka och återfinns då inte i den officiella polisiära statistiken på viltolyckor. Detta bortfall är ej kvantifierad men uppskattas ligga på kanske 5 % eller högre. Trafikolyckor med personskador (ca 1,6 % av alla viltolyckor) rapporteras vidare till databasen STRADA. Vår analys visade att i genomsnitt 37 % av alla viltrelate-rade personskadeolyckor under 2003–2012 inte var klassade som en viltolycka och därmed förmodligen inte heller fanns listat som viltolycka i Polisens T-RAR (trafikregister). När en olycka med vilt anmäls kontaktas i regel en kontaktperson kontaktperso-ner för att vid behov ta hand om det skadade djuret. Vid jägarens platsbesök skrivs en viltolycksrapport med detaljerade uppgifter om plats, tid och djurart. Inte alla rapporter (84 %) innehåller dock fullständiga och korrekta uppgifter som kan användas vid rumsliga analyser av olyckor. Det verkar även finnas en skevhet i viltolycksstatistiken med ca 12 % färre eftersök längs enskilda och kommunala vägar än förväntad.Tekniska problem i Polisens datasystem under 2012–2015 medförde dessutom att ett okänt antal anmälda viltolyckor inte registrerades i trafikregistren (T-rar, pust, k-rar). Det ledde till att det i vissa regioner och under vissa år finns fler viltolycksrapporter än polisrapporter. Vi uppskattar att detta bortfall kan ligga på minst 11 % i genomsnitt, under antagandet att rapporter från eftersöksjä-garna utfärdats för runt 90 % av alla polisregistrerade fall.Förenklat uttryckt står alltså den polisiära statistiken på viltolyckor under 2010 – 2015 för runt två-tredje delar av de verkligt inträffade olyckorna, medan efter-söksstatistiken i rumsliga analyser representerar ungefär hälften. Denna enkla tumregel bör dock användas försiktigt eftersom det finns tydliga avvikelser i mörkertalen mellan viltarterna, länen och åren.De olika bortfallen i statistiken har därmed en påtaglig effekt på den totala upp-skattningen av olyckstal. Vissa av orsakerna för bortfallen kan dock lätt åtgärdas eftersom de beror till stor del på brister i rutiner för registrering och data-bashantering. Vi rekommenderar därför en systematisk kontroll av databaserna och förbättrade kontrollmekanismer vid registrering och klassificering av an-mälda fall. Vi rekommenderar också att databaserna i STRADA, trafikregistret och eftersöksstatistiken länkas via ett gemensamt händelse-ID. Detta kan un-derlätta mycket vid framtida bortfallsanalyser. Vi föreslår även detaljstudier av hur olyckorna registreras och tolkas för att bättre kunna förebygga framtida bortfall.
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| 12. |
- Antonson, Hans, et al.
(författare)
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Experiencing moose and landscape while driving : a simulator and questionnaire study
- 2014
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Ingår i: Journal of Environmental Psychology. - : Elsevier. - 0272-4944 .- 1522-9610. ; 41, s. 91-100
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Tidskriftsartikel (refereegranskat)abstract
- Animal vehicle collisions (AVC's) have large economic, medical and ecological consequences but have rarely been studied with respect to driver behaviour. The aim of this study was to investigate different AVC-relevant landscape settings (vegetation cover), with and without game fencing and in combination with encountering moose. Twenty-five participants took part in an advanced driving simulator experiment. The results show that neither the presence of a game fence nor vegetation was found to affect driving speed, speed variability, lateral position or visual scanning in general. When a moose appeared at the side of the road, the drivers reacted by slowing down earlier and reducing their speed more when no game fence was present. Furthermore, the speed reduction when a moose was present was significantly larger when the vegetation was sparse. Game fencing made drivers feel at ease whereas dense vegetation was experienced as more stressful.
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| 13. |
- Arvidsson, Anna K, et al.
(författare)
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Klimatanpassning av vägkonstruktion, drift och underhåll
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Klimatförändringarna är en realitet och påverkar vårt samhälle och därigenom även våra transporter. Genom att klimatanpassa transportsystemen blir systemen mer robusta och risken för transportstörningar blir mindre. För vägars konstruktion, drift och underhåll innebär klimatanpassningen i de flesta fall relativt stora förändringar men det saknas idag en övergripande bild av det totala klimatanpassningsbehovet nationellt sett samt vilka åtgärder som behöver tas och som är rimliga att tas. Eftersom klimatförändringarna generellt varierar mellan Sveriges klimatzoner är det förenat med stora svårigheter att förutsäga vilken påverkan klimatförändringarna får på vägarnas beteende och livslängd. Inom vinterväghållningen i Sverige kommer saltanvändandet totalt sett att minska på grund av det varmare klimatet. Plogningstillfällena kommer antagligen minska, men beredskapen bör inte minskas för mycket eftersom de mer extrema tillfällena kommer att öka. För att lyckas klimatanpassa vägtransportsystemen så att de blir robusta konstaterar vi att det finns ett stort behov för att ta fram mer kunskap om vägkonstruktionens påverkan av ett förändrat klimat, samt inom drift och underhåll hur man skall anpassa sig genom olika typer av varierande och flexibla klimatanpassningsåtgärder och till effekterna av extrema väderhändelser.
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| 14. |
- Baruah, Gaurav, et al.
(författare)
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Impacts of seven years of experimental warming and nutrient addition on neighbourhood species interactions and community structure in two contrasting alpine plant communities
- 2018
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Ingår i: Ecological Complexity. - : Elsevier. - 1476-945X .- 1476-9840. ; 33:Supplement C, s. 31-40
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 15. |
- Biurrun, Idoia, et al.
(författare)
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Benchmarking plant diversity of Palaearctic grasslands and other open habitats
- 2021
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Ingår i: Journal of Vegetation Science. - Oxford : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 32:4
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Tidskriftsartikel (refereegranskat)abstract
- Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology. © 2021 The Authors.
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| 16. |
- Björk, Robert G., 1974, et al.
(författare)
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The effect of long-term temperature enhancement on the subarctic-alpine biocomplexity
- 2004
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Ingår i: International Conference on Arctic Microbiology.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Climate change is expected to alter the nitrogen availability and soil carbon dynamics and, as a consequence, affect plant community composition and production and thereby ecosystem gas flux rates. The International Tundra Experiment (ITEX) was established at Latnjajaure Field Station (LFS), in northern Swedish Lapland, in 1993 and gives a great opportunity to investigate the long-term effect of climatic warming on the soil ecosystem. The Open Top Chambers (OTCs) used within ITEX are located in five different plant communities, which covers both heaths and meadows and the gradient from dry to moist plant communities. The ITEX species Cassiope tetragona, Dryas octopetala, Eriophorum vaginatum, Polygonum viviparum and Ranunculus nivalis, studied at LFS, are all showing positive responses to phenology, growth and reproduction to the warming treatment. The temperature enhancement on the plant community level seems to lead to changes in the dominance of species, especially by shrubs and bryophytes. However, the overall plant community pattern also appears to depend much on changes in the nitrogen availability, where their combined effects are multiplicative rather than additive with a rapidly decrease in species diversity. In this newly started study we are adopting the results from the ITEX study and try to relate them to the soil processes and properties such as potential nitrification and denitrification, soil organic matter, C:N ratio and ecosystem respiration. Thus, we make an effort to amalgamate plant community changes with changes in the subarctic-alpine soil ecosystem.
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| 17. |
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| 18. |
- During, Heinjo J, et al.
(författare)
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Biomechanical properties of the terrestrial mosses Pleurozium schreberi (Brid.) Mitt. and Pogonatum japonicum Sull. & Lesq. along altitudinal gradients in northern Japan
- 2015
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Ingår i: Arctoa. - : KMK Scientific Press Ltd.. - 0131-1379. ; 24, s. 375-381
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Tidskriftsartikel (refereegranskat)abstract
- Altitudinal gradients along mountain slopes provide valuable opportunities to study variation in plant traits in response to changes in environmental conditions along such gradients. This study focused on biomechanical traits of two moss species, the more or less horizontally growing Pleurozium schreberi and the erect-growing Pogonatum japonicum, along altitudinal gradients on two mountains in Hokkaido, northern Japan.We measured stem diameter in two directions to determine the second moment of area I, used three-point bending tests with free stem ends to determine the slope of the force-deflection curve dF/dx, and used these data to calculate Young’s modulus and flexural rigidity of the stems. Both species showed much variation in all traits among replicates in the samples at each altitude. Environmental variation associated with altitude had more effect on the biomechanical traits of P. japonicum than on those of P. schreberi. Stems of P. japonicum were thicker (larger I) than those of P. schreberi and had a larger Young’s modulus and flexural rigidity. Stems tended to become thinner (lower second moment of area) and less rigid (lower flexural rigidity) at increasing altitude in both species.
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| 19. |
- Folkeson, Lennart, 1950-, et al.
(författare)
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State of preparedness for climate change adaptation in operations and maintenance of transport infrastructure in eight Swedish municipalities
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This study analysed the preparedness for climate change adaptation (CCA) of transport infrastructure in eight municipalities in Sweden. The study focused on municipal officials’ role in organizing and implementing CCA measures. The interviews were done in 2011. Many respondents confused CCA with climate change mitigation. Three of the municipalities had performed vulnerability analyses but apart from that, well-documented decision support in long-term adaptation was largely lacking. Adaptation measures were often based on day-to-day problems and recently experienced weather incidents. Strategic work with long-term CCA seemed to be largely lacking. The placing of the responsibility for CCA in the municipal organization was often unclear. Six of the respondents found there were no actual hindrances to their work with CCA and no conflicts with other municipal aims. However, several responses indicated budgetary competition with environmental aims or other societal strivings. The planning and implementation of CCA measures seemed to be highly dependent on individual officials, their engagement, their passivity/activity regarding this issue, their defined responsibility and the boundaries for their current position in the municipality organization.
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| 20. |
- Gren, Ing-Marie, et al.
(författare)
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Costs of air pollutants from shipping : a meta-regression analysis
- 2020
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Ingår i: Transport reviews. - : Taylor & Francis. - 0144-1647 .- 1464-5327. ; 40:4, s. 411-428
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Tidskriftsartikel (refereegranskat)abstract
- This study estimated the external cost of air pollution from shipping by means of a meta-regression analysis, which has not been made before. Three pollutants, which were included in most of the primary studies, were considered: nitrogen oxides (NOx), sulphur dioxides (SO2) and particulate matters with a diameter of max 2.5 micrometres (PM2.5). All primary studies included damages of health and a majority added impacts on agriculture and estimated the cost of air pollutants by transferring cost estimates from studies on costs of air emissions from transports in Europe. Different regression models and estimators were used and robust results were found of statistically significant emission elasticities of below one, i.e. total external costs increase by less than 1% when emissions increase by 1%. There was a small variation between the pollutants, with the highest elasticity for PM2.5 and lowest for NOx. Calculations of the marginal external cost of the pollutants showed the same pattern, with this cost being approximately six times higher for PM2.5 than for the other pollutants. Common to all pollutants was that the marginal external cost decreases when emission increases. Another robust result was a significant increase in the cost of studies published in journals compared with other publication outlets. These findings point out some caution when transferring constant external unit cost of air pollutant from shipping, which is much applied in the literature, and the cost functions estimated in this study could thus provide a complementary transfer mechanism.
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| 21. |
- Gren, Ing-Marie, et al.
(författare)
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Costs of traffic accidents with ungulates in Sweden
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 22. |
- Gren, Ing-Marie, et al.
(författare)
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Effects of shipping on non-indigenous species in the Baltic Sea
- 2022
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Ingår i: Science of the Total Environment. - Amsterdam : Elsevier. - 0048-9697 .- 1879-1026. ; 821
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Tidskriftsartikel (refereegranskat)abstract
- Shipping is regarded as an important vector for aquatic non-indigenous species (ANIS) worldwide. Less attention has been paid to its role in relation to environmental and economic causes of introduction and establishment, the knowledge of which is necessary to assess effects of changes in regulations on shipping. The purpose of this study was to estimate the impact of shipping on the incidence of ANIS in the Baltic Sea compared with environmental and economic factors. To this end, a production function was estimated with count data on ANIS (response variable) and shipping, environmental and economic factors as explanatory variables. Regression results from different regression models showed that shipping has a significant impact on ANIS incidence and can account for up to 38% of the number of ANIS in the sea. Predictions of the impact of measures implementing the Convention for the Control and Management of Ships' Ballast Water and Sediment indicated a reduction by 17% in the number of ANIS, which was counteracted by an expected increase in shipping traffic. © 2022
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| 23. |
- Häggmark Svensson, Tobias, et al.
(författare)
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Costs of traffic accidents with wild boar populations in Sweden
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 24. |
- Idoia Biurrun, Idoia, et al.
(författare)
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GrassPlot v. 2.00 – first update on the database of multi-scale plant diversity in Palaearctic grasslands
- 2019
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Ingår i: Palaearctic Grasslands. - : Eurasian Dry Grassland Group (EDGG). - 2627-9827. ; :44, s. 26-47
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Tidskriftsartikel (refereegranskat)abstract
- GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). Following a previous Long Database Report (Dengler et al. 2018, Phytocoenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems.
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| 25. |
- Janhäll, Sara, et al.
(författare)
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Vägnära vegetation i staden – påverkan på trafiksäkerhet och luftkvalitet
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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