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| 2. |
- Abrahamsson, Markus, et al.
(författare)
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Saproxylic beetle assemblages in artificially created high-stumps of spruce (Picea abies) and birch (Betula pendula/pubescens) – does the surrounding landscape matter?
- 2009
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Ingår i: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 2, s. 284-294
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Tidskriftsartikel (refereegranskat)abstract
- Abstract. 1. To create high-stumps (snags) is a common conservation action during final felling in Swedish production forests. However, many wood-living beetle species are only found in certain areas with higher overall biodiversity, so called hotspots. It has been argued that it is efficient to concentrate conservation efforts to hotspots. 2. The saproxylic beetle fauna was sampled on ten clearcuts inside hotspots and ten clearcuts outside the hotspots. They were collected with window traps mounted on 2- and 4-year-old spruce and birch high-stumps. We also used environmental data (e.g. tree species composition) to confirm differences between the surroundings of two, the clearcut types. 3. High-stumps on the hotspot clearcuts did not attract more saproxylic beetle species, or red-listed species, than high-stumps outside the hotspots. The environmental data showed that the clearcuts differed in several important aspects, for instance, were there a higher proportion of broadleaved trees around the hotspot compared with the clearcuts outside the hotspots. In a Canonical Correspondence Analysis, the proportion of coniferous and broadleaved forest was an important explanatory variables. The hotspot variable did contribute significantly in explaining the beetle composition on the birch high-stumps, but not on the spruce high-stumps. 4. In general, the study suggests that concentrating high-stumps to hotspot areas will not benefit more species. However, the result indicates birch high-stumps could be prioritised in a biologically rich landscape. The hotspot effect may be more noticeable in the future as the high-stumps decay and their importance for late successional species increase
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| 3. |
- Niklasson, Mats, et al.
(författare)
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Sensorimotor Therapy : Using Stereotypic Movements and Vestibular Stimulation to Increase Sensorimotor Proficiency of Children with Attentional and Motor Difficulties
- 2009
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Ingår i: Perceptual and Motor Skills. - : SAGE Publications. - 0031-5125 .- 1558-688X. ; 108:3, s. 643-669
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Tidskriftsartikel (refereegranskat)abstract
- The current naturalistic study examined whether sensorimotor therapy utilizing the training program, Retraining for Balance, might be an appropriate technique for sensorimotor proficiency. The 232 children (181 boys, 51 girls), whose mean age was 9.3 yr. (SD = 2.7), presented attentional and motor difficulties (according to the School Health Care) as indicated by their parents before starting therapy. The children were divided into three groups, i.e., a younger group (7 yr. old or younger, n = 65), a middle group (8 to 10 yr. old, n =91), and an older group (11 yr. old or older, n = 76). The program has seven parts, including fetal and neonatal movements, vestibular and auditory perceptual stimulation, and gross motor movements, among others. The treatment period was close to 3 yr. on the average. Analyses in a repeated-measures design indicated significant improvement of sensorimotor skills among the three age groups, but the older children performed better than the others on several tests. There were only a few sex differences. Retraining for Balance may be a functional technique for training children and youth with sensorimotor difficulties and might constitute a complement to regular treatment of Developmental Coordination Disorder, Learning Disability, and ADHD, but controlled studies are necessary before more decisive conclusions can be drawn.Read More: http://www.amsciepub.com/doi/abs/10.2466/pms.108.3.643-669
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| 4. |
- Christiansson, Rolf, et al.
(författare)
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Studier av sprängskador i Äspö-laboratoriet
- 2005
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Ingår i: Bergsprängningskommittén Diskussionsmöte BK 2005. - : Bergsprängningskommittén. ; , s. 139-152
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- En ny tunnel med 70 m längd byggdes på 450 m djup i Äspölaboratoriet 2003. Det ställdes speciella krav på begränsning av sprängskadezonens djup med hänsyn till planerade experiment.Tunneln drevs med galleri och bågformad låg pall för att minimera sprängskador i sulan. I huvuddelen av tunneln användes initieringsystemet Nonel MS och LP. I de tre sista salvorna av galleriet testades elektroniksprängkapslar. Skonsamhetsgraden för vägg och tak var normal med en tillåten skadezon på 0,3 m. Däremot tillämpades samma skonsamhetsgrad även för botten. I övrigt användes normal sprängteknik och normala sprängämnen som Dynotex 17 och Dynorex.Arbetet följdes noggrant genom dokumentation av utfört arbete. Vibrationsmätningar utfördes på nära håll samt på stort avstånd, 1,5 km från arbetsplatsen. Språng¬skador har undersökts genom sågning och sprickkartering.Föredraget kommer att presentera projektet, framförallt (1) erfarenheter från vibra¬tionsmätningar av samtliga sprängsalvor (noggrannheten i geofonmätningarna; totala antalet spränghål i salvorna; bomsalvor; avståndet från salvorna och geo¬logiska strukturer), (2) P-vågshastigheten i tunnelns närområde, (3) faktorer som påverkar utvecklingen av sprängskador, och (4) förslag på kontrollåtgärder som kan leda till att begränsa skadezonen i praktiskt tunnelarbete.
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| 6. |
- Drobyshev, Igor, et al.
(författare)
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Influence of annual weather on growth of pedunculate oak in southern Sweden
- 2008
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Ingår i: Annals of Forest Science. - : INRA, EDP Sciences. - 1286-4560 .- 1297-966X. ; 65:5, s. 512-512
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Tidskriftsartikel (refereegranskat)abstract
- A network of oak (Quercus robur L.) chronologies containing 49 sites and 635 single trees was analysed to identify weather variables affecting annual tree-ring increment dynamics in southern Sweden during 1860-2000. We analysed (1) the growth response of oak to non-extreme weather, and (2) the temporal and spatial patterns of regional growth anomalies (pointer years) and associated climatic extremes resolved on a monthly scale. Growth was controlled by precipitation in the current (June-July) and the previous growing season (August) in 48% and 22% of all sites, respectively. Temperature during July of the current year and August of the previous year was negatively correlated with growth in 29% and 43% of the sites, respectively. Growth was positively correlated with temperature in October of the previous season in 72% of the sites. The most extensive growth anomaly occured in 1965 and was probably caused by intrusion of cold Artic air masses into the region at the end of March that year. During the climatically non-extreme years, oak growth is driven mostly by the dynamics of summer precipitation. Many of the negative growth anomalies, however, were associated with temperature extremes. Southern Swedish oak pointer years tend not to coincide with the pan-European pointer years.
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| 7. |
- Drobyshev, Igor, et al.
(författare)
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Lifespan and mortality of old oaks - combining empirical and modelling approaches to support their management in Southern Sweden
- 2008
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Ingår i: Annals of Forest Science. - : Springer Science and Business Media LLC. - 1286-4560 .- 1297-966X. ; 65:4, s. 401-401
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Tidskriftsartikel (refereegranskat)abstract
- Old oaks (Quercus robur L.) play an important role in the southern Scandinavian landscape by providing habitat for a wide range of species, a large proportion of them being currently on the National Redlists. To provide support for the management of these trees, we review data on oak mortality and formulate a mortality-driven stochastic model analysing interactions between mortality rate, oak recruitment rate into 100-150 age class, and amount of oaks older than 200 years. Empirical annual mortality rates varied between 0 and 13% with average 1.68%. Trees older 200 years had an average mortality rate of 1.1%. Oaks in the high density forests showed higher mortality (3.2%) as compared to the trees growing in the low density forests (1.2%). A 400-year long modelling exercises indicated that under current mortality rates (regular mortality being centred around 1% annually; and irregular mortality 7% with average return time of 13 years) the long-term maintenance of 20 trees older than 200 years per ha would require an input rate of 1 to 5 trees x year(-1) x ha(-1) into the 100-150 years old class. The modelling highlighted the importance of initial oak abundance affecting amount of old trees at the end of shorter (100 years) simulation period.
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| 8. |
- Fritz, Örjan, et al.
(författare)
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Tree age is a key factor for the conservation of epiphytic lichens and bryophytes in beech forests
- 2009
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Ingår i: Applied Vegetation Science. - 1402-2001. ; 12, s. 93-106
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Tidskriftsartikel (refereegranskat)abstract
- Questions: What factors limit the distribution of epiphytic lichens and bryophytes at plot and tree level in beech forests? At what ages do epiphytic species, and species of conservation concern in particular, occur along a chronosequence of beech?Location: South-west Sweden.Method: Five hundred and seventy-one age-determined trees from 37 plots distributed among 29 beech-dominated stands were Surveyed along with a number of environmental (16) and substrate (seven) variables in a landscape of ca. 550ha. Non-metric multidimensional scaling (NMS) and indicator species analysis (ISA) were used for data analysis.Results: Plots containing old trees, confined to the base of slopes and with low impacts of recent forestry (thinning), generally had a high richness of species of conservation concern. Richness of common species and red-listed bryophytes were mostly related to the surveyed bark area. At tree level, primary factors explaining both species richness and composition were age, diameter at breast height and moss cover. There was a gradual replacement of tree age ranges for 58 lichens and 37 bryophytes along the chronosequence of beech. Red-listed lichens favoured damaged beech trees ( >= 180 years), whereas red-listed bryophytes were found on old and young steins in dense stands.Conclusions: Tree age exerts a profound influence on epiphytic lichens and bryophytes growing on beech. Many of the habitat specialists were found mainly on old beech because they inhabit specific substrates that occur on older trees. The association to high tree age commonly excludes red-listed lichens from conventionally managed beech forests with a 100- to 140-year rotation period.
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| 9. |
- Fröberg, Lars, et al.
(författare)
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Age and epiphytic lichen diversity of the dwarf shrub Helianthemum oelandicum on the island of Öland , Sweden
- 2009
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Ingår i: The Lichenologist. - : British Lichen Society. - 0024-2829 .- 1096-1135. ; 41:5, s. 537-545
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Tidskriftsartikel (refereegranskat)abstract
- Lichen cover and diversity was analysed on the dwarf shrub Helianthemum oelandicum (L.) Dum.Cours.at one site in the calcareous grassland of the area known as the 'Great Alvar' on the Island of Öland, Sweden. The age of 22 phorophytes was determined by ring counting and varied from 8 to 41 years and was accurately predicted by the root diameter. A total of 18 lichen species were found, with a range between 0 and 13 species per phorophyte. The number of lichen species on living H. oelandicum was correlated with the phorophyte age. The number of lichen species and their coverage was greater on dead compared with living phorophytes. The species number was also higher on thin branches compared with thick branches and roots and some of the species showed preferences for dead phorophytes, and for thin branches. This study of lichen colonization and growth on dwarf shrubs in relation to phorophyte age is a new application of herbchronology.
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| 10. |
- Granström, Anders, et al.
(författare)
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En brandhistorisk analys av Rossenområdet i västra Hälsingland
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Länsstyrelsen gav 2003 Anders Granström, universitetslektor vid institutionen för skoglig vegetationsekologi vid SLU i Umeå, och Mats Niklasson, forskare vid institutionen för sydsvensk skogsvetenskap på SLU i Alnarp, i uppdrag att göra en detaljerad analys av brandhistoriken i Rossenområdet. Det är ett cirka 1000 hektar stort talldominerat skogsområde väster om sjön Rossen i Ljusdals kommun. Den generella bild som träder fram för Rossenområdet är en brandregim med relativt täta bränder, som vanligen varit av så pass låg intensitet att trädskiktet av äldre tall överlevt, medan klenare ungtall samt gran dödats. Nu och då har elden dödat även bland äldre tall. Detta har antagligen skett på en skala från mindre fläckar upp till områden av flera hektar. De exakta mönstren är svåra att belägga, men de två mer koncentrerade provtagningarna som vi gjorde indikerar att nyrekrytering inom bestånden huvudsakligen har följt på de bränder som verkligen dödat i kronskiktet, och att det då inte rört sig om enstaka träd utan grupper. Det är troligt att bland annat topografin inverkat på denna storskaliga skogsstruktur. Inom delar av området var det mycket svårt att hitta riktigt gammalt (pre-1600) vedmaterial. Det gäller främst områdena väster och norr om Klimparna, där det är sannolikt att en brand under 1600-talet dödade på bred front. Områden med bruten topografi och inslag av myrmarker och öppet vatten har ofta ett större inslag av multipelt ljudad tall, troligen en följd av att brandfronten i sådana områden tenderar att brytas upp, med åtföljande sänkning av brandintensiteten (Granström opublicerat). Brandintervallen har varit korta, med ett medel av bara 40 år! En mycket stor del av bränderna har inträffat så pass kort tid efter föregående brand att bränslebädden inte varit fullt återställd (Schimmel & Granström 1997). Detta bör ha bidragit till den generellt låga brandintensiteten. Även i ett nationellt perspektiv är brandintervallen i Rossenområdet korta; väsentligt kortare än i Norra Norrlands inland och snarast i paritet med delar av Sydsveriges skogsbygder. Likaså inträder det obligatoriska brandavslutet tidigt i Rossen. En gradvis minskning av antalet bränder sker redan under slutet av 1700-talet och processen fullbordas före 1850. Det är några decennier tidigare än i övre Norrland och liknar återigen snarast situationen i södra Sverige (Niklasson opublicerat).
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