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Vegetation history of a primeval forest (Fiby urskog) in south Sweden is outlined from a paleoecological perspective. Pollen, spores, charcoal fragments and mineral particles were analyzed from a small, centrally placed wetland basin. 14C dating, diatom analysis and shore displacement data aided in dating the vegetation succession. Indicators of human impact and other disturbances, during the last ca 1000 years, are given particular attention, as well as Picea immigration. Elevated parts of Fiby area rose above the Littorina Sea level ca 7000 BP. Early establishing forest included Pinus , Betula, Alnus and Quercetum mixtum forest species. The wetland basin became isolated ca 5800 cal. yr BP. Drier conditions eventually permitted woody species such as Alnus and Betula to enter the basin from ca 4540 cal. yr BP, or earlier. Sedimentation stopped in the contemporary warm and dry conditions creating an hiatus. Paludification occurred and sedimentation resumed from ca 2600 cal. yr BP, turning the basin into Sphagnum fen with Menyanthes trifoliata , Lysimachia and Carex spp. Pinus and Betula maintained strong presence though some species, particularly Alnus, continued a decreasing trend. Fires were mainly restricted to bedrock outcrops. Last extensive fires were at ca 600 and 400 cal. yr BP. A much delayed Picea immigration commenced from ca 300 cal. yr BP, accompanied by a decline in forest fires. Occasional cereal and weed pollen indicating agricultural activity appear, but are considered as imports from surrounding landscapes. Gap phase dynamics evolve as the most important disturbance factor in the final Picea dominated forest. • Ca 7000 years of vegetation succession in Fiby forest, south Sweden, is outlined. • Pollen analysis provided no clear indicators of human disturbance in its central parts. • Picea abies came to dominate the forest only the latest 2–300 years, much delayed. • Forest fires, 400–600 years ago, have likely paved the way for Picea abies expansion. • The role of a severe storm AD 1795 in forming today's boreo-nemoral forest is proposed. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The initial establishment of Picea abies in Sweden and Norway on a landscape level, between 3000 and 1000 years ago, was often preceded by recurrent fire and thereafter the influence of fire decreased. However, in some swamp forests, the absence of fire over the last 3500 years has promoted the continuous presence of deciduous trees, i.e. Picea has not established although it has been present regionally for over 3000 years. Our objective was to study long-term vegetation development and fire history in a Picea swamp forest located close (c. 600 m) to a deciduous swamp forest with a documented fire-free history in northernmost Sweden. The study included analyses of charred particles, pollen and ignition residues. Principal component analysis was applied to identify major changes in the pollen spectra. Our results showed that the current Picea swamp forest has developed from a deciduous fen and that fires affected the fen between 6700 and 2300 cal. yr BP. Picea abies established on the fen around 2200 cal. yr BP, following the last local on-site fire. The main factors responsible for the local vegetation development have been: fire (6700 to 2300 cal. yr BP); autogenous processes and climate (2300 to 1000 cal. yr BP); autogenous processes or anthropogenic impact (1000 to 300 cal. yr BP); anthropogenic impact through selective cutting and grazing (300 to 100 cal. yr BP); and autogenous processes and grazing (100 cal. yr BP to present). We conclude that fire facilitated the initial Picea abies establishment. Once established, Picea abies created local conditions that in combination with a colder and wetter climate prevented fire and the establishment of other tree species. [ABSTRACT FROM AUTHOR]

To implement policies on sustainable forest management (SFM), there is a need to satisfy economical, ecological and socio-cultural sustainability objectives. Due to a long history of sustained yield wood production to satisfy the needs of the forest industry, clearfelling management systems are used in ∼96 per cent of managed forests in Sweden. To satisfy the intentions of contemporary forest and land use policies, uneven-aged forest management systems as a complement are currently debated. We interviewed local forestry stakeholders in the Swedish boreal forest region’s north and south about their views on and attitudes towards different forest management systems’ contribution to SFM. Most stakeholders were generally negative to the use of uneven-aged system for sustained yield wood production but saw advantages for ecological and socio-cultural dimensions of SFM. To encourage the use of even-aged cohort and uneven-aged systems to satisfy all dimensions of SFM, there is a need for improved communication, education and public awareness. This could ultimately lead to a more constructive and less heated debate. In addition, there is a need of more empirically based knowledge about uneven-aged and cohort forest management systems’ pros and cons when it comes to satisfying economical, ecological and socio-cultural objectives. [ABSTRACT FROM AUTHOR]

Background: Patellar tendinopathy (PT) is one of the most common reasons for sport-induced pain of the knee. Low ankle dorsiflexion range might predispose for PT because of load-bearing compensation in the patellar tendon.Purpose: The purpose of this 1-year prospective study was to analyze if a low ankle dorsiflexion range increases the risk of developing PT for basketball players.Study Design: Cohort study (prognosis); Level of evidence, 2.Methods: Ninety junior elite basketball players were examined for different characteristics and potential risk factors for PT, including ankle dorsiflexion range in the dominant and nondominant leg. Data were collected over a 1-year period and follow-up, including reexamination, was made at the end of the year.Results: Seventy-five players met the inclusion criteria. At the follow-up, 12 players (16.0%) had developed unilateral PT. These players were found to have had a significantly lower mean ankle dorsiflexion range at baseline than the healthy players, with a mean difference of −4.7° (P = .038) for the dominant limb and −5.1° (P = .024) for the nondominant limb. Complementary statistical analysis showed that players with dorsiflexion range less than 36.5° had a risk of 18.5% to 29.4% of developing PT within a year, as compared with 1.8% to 2.1% for players with dorsiflexion range greater than 36.5°. Limbs with a history of 2 or more ankle sprains had a slightly less mean ankle dorsiflexion range compared to those with 0 or 1 sprain (mean difference, −1.5° to −2.5°), although this was only statistically significant for nondominant legs.Conclusion: This study clearly shows that low ankle dorsiflexion range is a risk factor for developing PT in basketball players. In the studied material, an ankle dorsiflexion range of 36.5° was found to be the most appropriate cutoff point for prognostic screening. This might be useful information in identifying at-risk individuals in basketball teams and enabling preventive actions. A history of ankle sprains might contribute to reduced ankle dorsiflexion range. [ABSTRACT FROM AUTHOR]

The high-altitude forests along the Scandinavian mountain range were relatively unaffected by the first wave of forest utilization and in the mid-twentieth century some untouched forests still remained. In his doctoral thesis, Tore Arnborg analysed the vegetation patterns and forest structure in two mainly primeval forest stands, Blekaskogen and Granudden, in northern Sweden. The sites represent typical spruce-dominated mountain forest, generally not subject to large-scale disturbance by forest fire. Arnborg's studies were among the first giving data on the structure and dynamics of these forests. Both stands were multilayered and of open character. The fraction of mature, overmature and senescent trees was high and about 18% of the trees were considered to be dying. Although having a similar history, the two stands differed in character, mostly owing to the altitudinal difference. Thus, Granudden, situated about 50-80 m above Blekaskogen, had a low canopy and was more open in character. In addition to stand structure, Arnborg analysed tree regeneration. He provided very strong empirical evidence for the important role of dead logs in regeneration. Based on logs of known age, he presented an eight-grade decay classification system, focusing on the possibility of seed germination and survival. A major conclusion from his studies is that the forest is in equilibrium and able to regenerate itself by the periodically high abundance of viable seeds and through the presence of logs and disturbed soil patches. Based on his findings, Arnborg argued for initiating clear-cutting complemented with soil scarification of these high-altitude forests. In his time, just before the onset of the clear-cutting epoch, the focus in forest research was strongly influence by management for increased production. [ABSTRACT FROM AUTHOR]

Swedish forestry has successfully developed systems for sustained yield production of wood. Silvicultural techniques are today completely dominated (96%) by clear-felling methods. By contrast, Swedish natural forests and preindustrial cultural woodlands were ecologically and culturally diverse, with a substantial proportion having a continuous tree cover as a response to natural disturbance dynamics and preindustrial agricultural land management. If forest management systems do not mimic this diversity of disturbance regimes sufficiently well, the scope of sustainable forest management to include biodiversity and sociocultural values will not be met. This study estimated the past and present amount of one cultural and two natural disturbance regimes known to deliver continuous tree cover in two study areas located around two important biophysical and sociocultural transition zones in northern and southern Sweden, respectively. Several approaches were used to estimate the amount of remaining continuous tree cover forests. The results indicate that 9-10% of the study areas is made up by site types that historically would have held a large proportion of continuous tree cover forests. Estimates for productive site types show that only 1-2% of these sites remain in southern Sweden and 10-20% in northern Sweden. The data indicate that present management in both study areas is similar. Thus, these differences between the regions will disappear in a few decades. To achieve the aim of Swedish forest and environmental policies there is a clear need to develop and use alternative forest management methods on appropriate sites. [ABSTRACT FROM AUTHOR]

This study aims to demonstrate the potential of a process-based regional ecosystem model, LPJ-GUESS, driven by climate scenarios generated by a regional climate model system (RCM) to generate predictions useful for assessing effects of climatic and CO2 change on the key ecosystem services of carbon uptake and storage. Scenarios compatible with the A2 and B2 greenhouse gas emission scenarios of the Special Report on Emission Scenarios (SRES) and with boundary conditions from two general circulation models (GCMs) - HadAM3H and ECHAM4/OPYC3 - were used in simulations to explore changes in tree species distributions, vegetation structure, productivity and ecosystem carbon stocks for the late 21st Century, thus accommodating a proportion of the GCM-based and emissions-based uncertainty in future climate development. The simulations represented in this study were of the potential natural vegetation ignoring direct anthropogenic effects. Results suggest that shifts in climatic zones may lead to changes in species distribution and community composition among seven major tree species of natural Swedish forests. All four climate scenarios were associated with an extension of the boreal forest treeline with respect to altitude and latitude. In the boreal and boreo-nemoral zones, the dominance of Norway spruce and to a lesser extent Scots pine was reduced in favour of deciduous broadleaved tree species. The model also predicted substantial increases in vegetation net primary productivity (NPP), especially in central Sweden. Expansion of forest cover and increased local biomass enhanced the net carbon sink over central and northern Sweden, despite increased carbon release through decomposition processes in the soil. In southern Sweden, reduced growing season soil moisture levels counterbalanced the positive effects of a longer growing season and increased carbon supply on NPP, with the result that many areas were converted from a sink to a source of carbon by the late 21st century. The economy-oriented A2 emission scenario would lead to higher NPP and stronger carbon sinks according to the simulations than the environment-oriented B2 scenario. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We estimated the need for nature reserves to maintain forest biodiversity in Sweden. Using habitat-loss thresholds for long-term survival of resident vertebrate ''umbrella'' species, and differences in forest disturbance regimes, we estimated the long-term protection in four biogeographic regions. No reserve need was assumed for forest environments that can be emulated by normal management. The estimates of the long-term need of reserves ranged from 9% (northern Sweden) to 16% southernmost Sweden) and was divided into: (1) existing protected forests (1.6–0.6%); (2) estimated benefits for biodiversity of special forest management (0.7–0%); (3) existing unprotected forests with high conservation value (3.5–1.9%). The remaining areas required to satisfy the long-term reserve goal were cultural landscape habitats (0–2.2%), as well as land for habitat restoration and re-creation (3–11%). Our analysis suggests that it is urgent to maintain all remnants of natural forests and cultural landscape habitats, but that forest protection alone is insufficient to maintain forest biodiversity. [ABSTRACT FROM AUTHOR]