| 1. |
- Aldea, Jorge, et al.
(författare)
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Current and future drought vulnerability for three dominant boreal tree species
- 2024
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Ingår i: Global Change Biology. - 1354-1013 .- 1365-2486. ; 30
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is projected to increase the frequency and severity of droughts, possibly causing sudden and elevated tree mortality. Better understanding and predictions of boreal forest responses to climate change are needed to efficiently adapt forest management. We used tree-ring width chronologies from the Swedish National Forest Inventory, sampled between 2010 and 2018, and a random forest machine-learning algorithm to identify the tree, stand, and site variables that determine drought damage risk, and to predict their future spatial–temporal evolution. The dataset consisted of 16,455 cores of Norway spruce, Scots pine, and birch trees from all over Sweden. The risk of drought damage was calculated as the probability of growth anomaly occurrence caused by past drought events during 1960–2010. We used the block cross-validation method to compute model predictions for drought damage risk under current climate and climate predicted for 2040–2070 under the RCP.2.6, RCP.4.5, and RCP.8.5 emission scenarios. We found local climatic variables to be the most important predictors, although stand competition also affects drought damage risk. Norway spruce is currently the most susceptible species to drought in southern Sweden. This species currently faces high vulnerability in 28% of the country and future increases in spring temperatures would greatly increase this area to almost half of the total area of Sweden. Warmer annual temperatures will also increase the current forested area where birch suffers from drought, especially in northern and central Sweden. In contrast, for Scots pine, drought damage coincided with cold winter and early-spring temperatures. Consequently, the current area with high drought damage risk would decrease in a future warmer climate for Scots pine. We suggest active selection of tree species, promoting the right species mixtures and thinning to reduce tree competition as promising strategies for adapting boreal forests to future droughts.
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| 2. |
- Becs, Artis, et al.
(författare)
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Development of crop trees after different thinning methods in mixed Norway spruce (Picea abies L.) and Birch (Betula spp.) forests in Southern Sweden
- 2024
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Ingår i: Forest Ecology and Management. - 0378-1127 .- 1872-7042. ; 566
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Tidskriftsartikel (refereegranskat)abstract
- In Northern Europe, novel thinning methods of small diameter trees are being tested to promote early competition release in young tree -dense forests at a low cost. These methods involve harvesting the whole aboveground tree biomass in 1 - 2 m wide strips between extraction racks (i.e. strip roads). Before recommending such methods to practical forestry, we need to know how the growth of remaining stand and individual trees perform at different stages of stand rotation to avoid compromising future forest production and the overall economy. Therefore, we analysed data from three Norway spruce dominated experimental sites in Southern Sweden with conventional selective biomass thinning (BT) versus geometrical BT in strips, where trees between extraction racks are cut in 1 - 2 m wide, ca. 10 m long strips (i.e. boom -corridor thinning) including unthinned reference treatment. To assess the thinning effect on the remaining stand, we analysed data from the remaining trees five to six years after thinning. We compared stand properties such as standing volume, diameter, height, basal area, volume increment, basal area increment and damages for different cohorts of the remaining trees. We found that BT in 1 - 2 m wide strips do not affect the growth and yield of the most important crop trees (i.e. the 500 -largest crop trees and the next 400 -largest crop trees) and to some extent protect the remaining stand from damages. Although not statistically significant, we observed that for the cohort of the 500 -largest crop trees, the proportions of new damages were lower in unthinned treatment (4.8 %), and strict BT in 1 - 2 m wide strips (1.7 % and 5.8 % respectively) than in conventional BT (14.4 %) and semi -selective BT in 1 m wide strips (7.9 %). A similar pattern was seen for the next 400 -largest crop trees. Thus, these short-term results suggests that BT in narrow strips of 1 - 2 m can be used in young tree -dense forests in Southern Sweden without compromising the development of the remaining crop trees. However, more long-term research on a broader geographical scale is required before we can fully recommend these novel -thinning methods to forest owners across the Northern Europe on a large scale.
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| 3. |
- Fredriksson, Mio, 1976-, et al.
(författare)
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Caesarean section on maternal request : a qualitative study of conflicts related to shared decision-making and person-centred care in Sweden
- 2024
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Ingår i: Reproductive Health. - : BioMed Central (BMC). - 1742-4755. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundToday, person-centred care is seen as a cornerstone of health policy and practice, but accommodating individual patient preferences can be challenging, for example involving caesarean section on maternal request (CSMR). The aim of this study was to explore Swedish health professionals' perspectives on CSMR and analyse them with regard to potential conflicts that may arise from person-centred care, specifically in relation to shared decision-making.MethodsA qualitative study using both inductive and deductive content analysis was conducted based on semi-structured interviews. It was based on a purposeful sampling of 12 health professionals: seven obstetricians, three midwives and two neonatologists working at different hospitals in southern and central Sweden. The interviews were recorded either in a telephone call or in a video conference call, and audio files were deleted after transcription.ResultsIn the interviews, twelve types of expressions (sub-categories) of five types of conflicts (categories) between shared decision-making and CSMR emerged. Most health professionals agreed in principle that women have the right to decide over their own body, but did not believe this included the right to choose surgery without medical indications (patient autonomy). The health professionals also expressed that they had to consider not only the woman's current preferences and health but also her future health, which could be negatively impacted by a CSMR (treatment quality and patient safety). Furthermore, the health professionals did not consider costs in the individual decision, but thought CSMR might lead to crowding-out effects (avoiding treatments that harm others). Although the health professionals emphasised that every CSMR request was addressed individually, they referred to different strategies for avoiding arbitrariness (equality and non-discrimination). Lastly, they described that CSMR entailed a multifaceted decision being individual yet collective, and the use of birth contracts in order to increase a woman's sense of security (an uncomplicated decision-making process).ConclusionsThe complex landscape for handling CSMR in Sweden, arising from a restrictive approach centred on collective and standardised solutions alongside a simultaneous shift towards person-centred care and individual decision-making, was evident in the health professionals' reasoning. Although most health professionals emphasised that the mode of delivery is ultimately a professional decision, they still strived towards shared decision-making through information and support. Given the different views on CSMR, it is of utmost importance for healthcare professionals and women to reach a consensus on how to address this issue and to discuss what patient autonomy and shared decision-making mean in this specific context. Person-centered care is today a widespread approach, but accommodating individual patient preferences can be challenging, for example involving caesarean section on maternal request (CSMR). This study examines Swedish health professionals' views on CSMR. Interviews with 12 health professionals reveal conflicts between CSMR and key aspects of person-centered care, in particular shared decision-making. While professionals acknowledge women's autonomy, they question CSMR without medical need. Concerns include for example treatment quality and patient safety, and avoiding treatments that harm others. The Swedish context, balancing collective solutions with individualized care, complicates decision-making. Unlike countries with more private healthcare, where CSMR support might be higher, Swedish health professionals emphasize shared decision-making despite viewing the mode of delivery as primarily a professional decision. This study sheds light on the challenges in integrating CSMR into person-centered care frameworks.
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| 4. |
- Karlsson, Matts Ingemar, et al.
(författare)
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Birch establishes anywhere! So, what is there to know about natural regeneration and direct seeding of birch?
- 2024
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Ingår i: New Forests. - 0169-4286 .- 1573-5095. ; 55, s. 157-171
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Tidskriftsartikel (refereegranskat)abstract
- We tested three soil scarification approaches of varying intensity (intensive preparation exposing bare mineral soil, medium intensity with a mixture of organic material and mineral soil, and control without site preparation) on six clear-felled sites in two localities in northern and central Sweden between 2018 and 2021. The effect of soil scarification intensity and soil moisture on the occurrence of naturally regenerated birch seedlings was tested one, two and three years after soil scarification, and the density of direct-seeded birch seedlings one year after seeding. In addition, we tested the effect of the annual seed rain, and differences between the two birch species, on the density of direct-seeded seedlings. Soil scarification and its interaction with soil moisture had a significant positive effect on both the occurrence of naturally regenerated birch seedlings and the density of direct-seeded birch seedlings. There was no significant effect of neither annual natural seed rain nor species choice on direct-seeded seedling density. Time since soil scarification had a significant effect on the occurrence of naturally regenerated birch seedlings. In moist soils with high volumetric water content (>= 28%), birch seeds germinate at high rates and seedlings survive without soil scarification. In mesic soils, birch seeds germinate with higher rates after soil scarification. In dry soils, birch seeds rarely germinate regardless of any disturbance of the humus layer.
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| 5. |
- Ogana, Friday Nwabueze, et al.
(författare)
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Growth response of Pinus sylvestris L. and Picea abies [L.] H. Karst to climate conditions across a latitudinal gradient in Sweden
- 2024
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Ingår i: Agricultural and Forest Meteorology. - 0168-1923 .- 1873-2240. ; 353
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Tidskriftsartikel (refereegranskat)abstract
- Pinus sylvestris L. (Scots pine) and Picea abies [L.] H. Karst. (Norway spruce) are the most important economic tree species in Sweden. However, like every other tree species, they are affected by climate change, especially drought conditions. In this study, we analysed the effect of climate variability on the radial growth of Scots pine and Norway spruce in Sweden. Sixteen sites of pairwise monospecific stands of Scots pine and Norway spruce distributed across latitudinal gradients in Sweden (55 - 67 degrees N) were used. In each site, we sampled at least 15 dominant/codominant Scots pine and Norway spruce trees without any defect in the sampled plots' buffer zone (3 - 5 m wide). We performed a correlation analysis between climate variables and the radial growth of the species using different timescales; and regressed the coefficients with latitudes. Thereafter, important climate variables for both species were identified. Our results showed that temperature is the main climate factor affecting the radial growth of Scots pine while Norway spruce is more sensitive to early summer precipitation. The impact of summer precipitation on the radial growth of both species transitioned from a positive to a negative trend across a latitudinal gradient. Conversely, a contrasting pattern was noted in the relationship with summer temperature. The radial growth of both species responded positively to spring temperature, particularly at lower latitudes. The resistance of pine and spruce to drought showed a clear linear increase with latitude (p < 0.001). Compared to spruce, pine showed a better capacity to attain pre-drought growth levels (i.e., resilience) and was independent of latitude. Our findings contribute to the understanding of the spatial patterns of the growth-climate relationship of Scots pine and Norway spruce in Sweden; and could offer useful guidance on adaptive forest management in the face of climate change.
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| 6. |
- Persson, Magnus, et al.
(författare)
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Exploring the interplay between within-stand variation and thinning practices in southern Sweden
- 2024
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Ingår i: Forest Ecology and Management. - : Elsevier. - 0378-1127 .- 1872-7042. ; 561
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Tidskriftsartikel (refereegranskat)abstract
- The state of within-stand variation (WSV) in boreal, coniferous production forests and how it is dealt with in thinning operations is a scarcely researched topic. In the autumn of 2018, we surveyed a series of Norway spruce (Picea abies (L.) Karst) or Scots pine (Pinus sylvestris L.) dominated production stands scheduled for first commercial thinning from below. Here, we evaluate the potential causes of WSV in basal area, how WSV was addressed in the thinning operations, and finally how the stands and subsequent thinning practice conformed with the basal area target specified in the thinning guidelines. WSV in the yield attributes was defined as the dispersion in a stand attribute within a stand and quantified using the Qn scale estimator (a robust measure of dispersion). First, WSV in basal area at the time of first thinning was evaluated as a function of WSV in stem number and WSV in site index. Next, yield attributes before and after thinning were compared using paired ttests, and the future development of WSV in basal area was evaluated using linear mixed-effects models. Finally, the thinning practice was evaluated before and after thinning by modelling the compliance with the basal area target as a function of stem number and dominant height, also using linear mixed-effects models. WSV in basal area appeared to be influenced by WSV in site index and WSV in stem number for Norway spruce, but not for Scots pine. Thinning reduced the WSV in basal area, standing volume, and stem number, while dominant height, quadratic mean diameter and basal area weighted mean height remained unaffected. At first thinning, compliance with the thinning guideline increased with increasing stem density and dominant height. However, moderate to high compliance with the basal area target in the thinning guidelines was only reached for plots with elevated dominant height (>15 m) in combination with high stem number (>2250 N ha-1). Thus, the recommended range in dominant height (12-14 m) for first thinning was generally exceeded, which may be attributed to the generally low stem number at the time of thinning. This study suggests that sub-optimal regeneration efforts and management of young forests can lead to WSV across a wide range of stand attributes, and likely also reductions in yield. Thinning decreased WSV in basal area, standing volume and stem number, however, the plots were heavily thinned to such a degree that it could potentially cause production losses.
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| 7. |
- Petersson, Lisa, et al.
(författare)
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Potential implications of shortened rotation length for forest birds, bryophytes, lichens and vascular plants: An example from southern Swedish production forests
- 2024
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Ingår i: PLoS ONE. - 1932-6203. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- The rotation lengths of intensively managed production forests may be altered to achieve a variety of goals, with correspondingly implications for biodiversity. Here we consider the potential implications of shortened rotation times for biodiversity in planted monocultures of the two most common production tree species in Sweden, Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). To do so we surveyed bird, bryophyte, epiphytic lichen and vascular plant diversity in 80 and 55-year-old stands; stand ages which approximate present-day and potential future rotation lengths in this region respectively. We found clear differences in the species communities of the 55 compared to the 80-year-old stands for both understory species and epiphytes, but not for birds. Nevertheless, bird species richness was still highest in the 80-year-old Norway spruce dominated stands. Dead wood amount was also highest the 80-year-old Norway spruce stands. Highest species richness of epiphytic lichens was found in 80-year-old Scots pine stands. However, 55-year-old Scots pine stands had a higher understory species richness and diversity than the older Scots pine stands, including a larger number of open land species. The 80-year-old forest stands examined may be considered old with respect to production forest rotation lengths in Sweden but are relatively young when comparing stand ages of unmanaged natural forest stands. Nevertheless, our results indicate that shortening the rotation time of Scots pine and Norway spruce, in this part of Sweden from 80 to 55 years, could have important consequences for forest biodiversity. These consequences are primarily inferred from the likely implications from shortened rotations for lichens community composition and diversity in both Norway spruce and Scots pine stands, as well as impacts on understory plant species in Norway spruce stands.
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| 8. |
- Trubins, Renats, et al.
(författare)
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Abandoning conversion from even-aged to uneven-aged forest stands - the effects on production and economic returns
- 2024
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Ingår i: Scandinavian Journal of Forest Research. - 0282-7581 .- 1651-1891. ; 39, s. 77-88
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Tidskriftsartikel (refereegranskat)abstract
- There is growing interest in continuous cover forestry in Sweden. The historical domination of even-aged forest management means there is a need to focus on methods for transforming even-aged to uneven-aged stands. Practical conversion management today is highly adaptive, and the possibility of failures, such as persistent lack of tree recruitment, must be allowed for. We used simulations to evaluate various scenarios in which conversion management is introduced at different development stages in even-aged stands and then abandoned in favour of clear-felling. A shift towards an inverse J-shaped diameter distribution at the end of the simulations was most evident in northern Sweden and with an early introduction of conversion forestry. The largest losses were incurred in a scenario where the conversion management started with removing larger trees at pre-commercial thinning: it reduced the volume of production by up to 25% and, if clear-felled, resulted in a lower land expectation value than conventional management. Earlier decision to abandon conversion management reduced the losses, but the effect of timing was minor. In summary, the results indicate that conversion management could be started and abandoned without any major economic loss during the timeframe of a normal rotation.
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