| 1. |
- Dahlgren, Jonas, et al.
(författare)
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Positive feedbacks and alternative stable states in forest leaf types
- 2024
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Ingår i: Nature Communications. - 2041-1723. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- The emergence of alternative stable states in forest systems has significant implications for the functioning and structure of the terrestrial biosphere, yet empirical evidence remains scarce. Here, we combine global forest biodiversity observations and simulations to test for alternative stable states in the presence of evergreen and deciduous forest types. We reveal a bimodal distribution of forest leaf types across temperate regions of the Northern Hemisphere that cannot be explained by the environment alone, suggesting signatures of alternative forest states. Moreover, we empirically demonstrate the existence of positive feedbacks in tree growth, recruitment and mortality, with trees having 4–43% higher growth rates, 14–17% higher survival rates and 4–7 times higher recruitment rates when they are surrounded by trees of their own leaf type. Simulations show that the observed positive feedbacks are necessary and sufficient to generate alternative forest states, which also lead to dependency on history (hysteresis) during ecosystem transition from evergreen to deciduous forests and vice versa. We identify hotspots of bistable forest types in evergreen-deciduous ecotones, which are likely driven by soilrelated positive feedbacks. These findings are integral to predicting the distribution of forest biomes, and aid to our understanding of biodiversity, carbon turnover, and terrestrial climate feedbacks.
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| 2. |
- Esseen, Per-Anders, et al.
(författare)
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Multiple drivers of large-scale lichen decline in boreal forest canopies
- 2022
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 28:10, s. 3293-3309
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Tidskriftsartikel (refereegranskat)abstract
- Thin, hair-like lichens (Alectoria, Bryoria, Usnea) form conspicuous epiphyte communities across the boreal biome. These poikilohydric organisms provide important ecosystem functions and are useful indicators of global change. We analyse how environmental drivers influence changes in occurrence and length of these lichens on Norway spruce (Picea abies) over 10 years in managed forests in Sweden using data from >6000 trees. Alectoria and Usnea showed strong declines in southern-central regions, whereas Bryoria declined in northern regions. Overall, relative loss rates across the country ranged from 1.7% per year in Alectoria to 0.5% in Bryoria. These losses contrasted with increased length of Bryoria and Usnea in some regions. Occurrence trajectories (extinction, colonization, presence, absence) on remeasured trees correlated best with temperature, rain, nitrogen deposition, and stand age in multinomial logistic regression models. Our analysis strongly suggests that industrial forestry, in combination with nitrogen, is the main driver of lichen declines. Logging of forests with long continuity of tree cover, short rotation cycles, substrate limitation and low light in dense forests are harmful for lichens. Nitrogen deposition has decreased but is apparently still sufficiently high to prevent recovery. Warming correlated with occurrence trajectories of Alectoria and Bryoria, likely by altering hydration regimes and increasing respiration during autumn/winter. The large-scale lichen decline on an important host has cascading effects on biodiversity and function of boreal forest canopies. Forest management must apply a broad spectrum of methods, including uneven-aged continuous cover forestry and retention of large patches, to secure the ecosystem functions of these important canopy components under future climates. Our findings highlight interactions among drivers of lichen decline (forestry, nitrogen, climate), functional traits (dispersal, lichen colour, sensitivity to nitrogen, water storage), and population processes (extinction/colonization).
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| 3. |
- Fridman, Jonas, et al.
(författare)
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Co-limitation towards lower latitudes shapes global forest diversity gradients
- 2022
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Ingår i: Nature ecology & evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 6, s. 1423-1437
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Tidskriftsartikel (refereegranskat)abstract
- The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025 degrees x 0.025 degrees) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from similar to 1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers.
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| 4. |
- Fridman, Jonas, et al.
(författare)
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Global patterns and environmental drivers of forest functional composition
- 2024
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Ingår i: Global Ecology and Biogeography. - 1466-822X .- 1466-8238. ; 33, s. 303-324
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Tidskriftsartikel (refereegranskat)abstract
- AimTo determine the relationships between the functional trait composition of forest communities and environmental gradients across scales and biomes and the role of species relative abundances in these relationships.LocationGlobal.Time periodRecent.Major taxa studiedTrees.MethodsWe integrated species abundance records from worldwide forest inventories and associated functional traits (wood density, specific leaf area and seed mass) to obtain a data set of 99,953 to 149,285 plots (depending on the trait) spanning all forested continents. We computed community-weighted and unweighted means of trait values for each plot and related them to three broad environmental gradients and their interactions (energy availability, precipitation and soil properties) at two scales (global and biomes).ResultsOur models explained up to 60% of the variance in trait distribution. At global scale, the energy gradient had the strongest influence on traits. However, within-biome models revealed different relationships among biomes. Notably, the functional composition of tropical forests was more influenced by precipitation and soil properties than energy availability, whereas temperate forests showed the opposite pattern. Depending on the trait studied, response to gradients was more variable and proportionally weaker in boreal forests. Community unweighted means were better predicted than weighted means for almost all models.Main conclusionsWorldwide, trees require a large amount of energy (following latitude) to produce dense wood and seeds, while leaves with large surface to weight ratios are concentrated in temperate forests. However, patterns of functional composition within-biome differ from global patterns due to biome specificities such as the presence of conifers or unique combinations of climatic and soil properties. We recommend assessing the sensitivity of tree functional traits to environmental changes in their geographic context. Furthermore, at a given site, the distribution of tree functional traits appears to be driven more by species presence than species abundance.
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| 5. |
- Fridman, Jonas, et al.
(författare)
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The global biogeography of tree leaf form and habit
- 2023
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Ingår i: Nature Plants. - 2055-026X .- 2055-0278. ; 9, s. 1795-1809
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Tidskriftsartikel (refereegranskat)abstract
- Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4Gt), 54% (335.7Gt), 22% (136.2Gt) and 3% (18.7Gt), respectively. We further project that, depending on future emissions pathways, 17-34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling. Integrating inventory data with machine learning models reveals the global composition of tree types-needle-leaved evergreen individuals dominate, followed by broadleaved evergreen and deciduous trees-and climate change risks.
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| 6. |
- Fridman, Jonas, et al.
(författare)
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The number of tree species on Earth
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 119
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Tidskriftsartikel (refereegranskat)abstract
- One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global groundsourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are 73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness.
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| 7. |
- Holmström, Emma, et al.
(författare)
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Current state of mixed forests available for wood supply in Finland and Sweden
- 2023
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Ingår i: Scandinavian Journal of Forest Research. - 0282-7581 .- 1651-1891. ; 38, s. 442-452
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Tidskriftsartikel (refereegranskat)abstract
- This study's objectives were to suggest harmonised criteria for the definition of mixed forests for two Nordic countries, describe their principal mixture types, and provide an overview of their current extent. We used national forest inventory data compiled in Finland and Sweden, considering the forest available for wood supply (FAWS), excluding seedling and sapling plots before canopy closure. The definition of the mixed forest was based on the threshold criteria, which indicate the basal area proportion of the dominant tree species of the total in a stand. The proportion of mixed forests increased with higher threshold criteria: 21% to 42% in Finland and 24% to 49% in Sweden, as the threshold criterion was changed from 65% to 85%. With a threshold criterion of 75%, the area of mixed FAWS was 5.6 million ha (31% of FAWS) in Finland and 6.5 million ha (36%) in Sweden. The dominant mixture type was the pine-spruce-birches mixture (31%) in Finland and the pine-spruce mixture (29%) in Sweden. The proportion of peatland forest of mixed forests was similar in the countries: 9-10%. The mixed forests proportion increased from north boreal to hemiboreal, increasing with more mature development classes.
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| 8. |
- Jonsson, Bengt-Gunnar, 1963-, et al.
(författare)
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Rapid changes in ground vegetation of mature boreal forests : an analysis of Swedish national forest inventory data
- 2021
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Ingår i: Forests. - : MDPI. - 1999-4907. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- The boreal forest floor vegetation is critical for ecosystem functioning and an important part of forest biodiversity. Given the ongoing global change, knowledge on broad-scale changes in the composition and abundance of different plant species and species groups is hence important for both forest conservation and management. Here, we analyse permanent plot data from the National Forest Inventory (NFI) on changes in the vegetation over a 10-year period in four regions of Sweden. To limit the direct and relatively well-known effects of forest management and associated succession, we only included mature forest stands not influenced by forestry during the 10 years between inventories, and focused on vegetation change mainly related to other factors. Results show strong decrease among many species and species groups. This includes dominant species such as Vaccinimum myrtillus and Deschampsia flexuosa as well as several forest herbs. The only species increasing are some mosses in the southern regions. Our data do not allow for a causal interpretation of the observed patterns. However, the changes probably result from latent succession in combination with climate change and nitrogen deposition, and with time lags complicating the interpretation of their relative importance. Regardless of the cause, the observed changes are on a magnitude that suggest impacts on ecosystem functioning and hence highlight the need for more experimental work.
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| 9. |
- Nilsson, Mats, et al.
(författare)
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Improved large-area forest increment information in Europe through harmonisation of National Forest Inventories
- 2024
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Ingår i: Forest Ecology and Management. - 0378-1127 .- 1872-7042. ; 562
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Tidskriftsartikel (refereegranskat)abstract
- Consistent knowledge about the increment in European forests gained amplified importance in European policies and decision processes related to forest -based bioeconomy, carbon sequestration, sustainable forest management and environmental changes. Until now, large -area increment information from European countries was lacking international comparability. In this study we present a harmonisation framework in accordance with the principles and the approach established for the harmonisation of National Forest Inventories (NFIs) in Europe. 11 European NFIs, representing a broad range of increment measurement and estimation methods, developed unified reference definitions and methods that were subsequently implemented to provide harmonised increment estimates by NUTS regions (Nomenclature of territorial units for statistics of the European Union), main forest types and tree species groups, and to rate the impact of harmonisation measures. The main emphasis was on gross annual increment (GAI), however, also annual natural losses (ANL) and net annual increment (NAI) were estimated. The data from the latest available NFI cycles were processed. The participating countries represent a forest area of about 130 million ha, and 82% of the European Unions ' (EU) forest area, respectively. The increments were estimated in terms of volume (m 3 year - 1 , m 3 ha - 1 year -1 ) and above -ground biomass (t year - 1 , t ha -1 year -1 ). The harmonised GAI volume estimates deviate in a range of +12.3% to -26.5% from the estimates according to the national definitions and estimation methods. Within the study area, the harmonised estimates show a considerable range over the NUTS regions for GAI, from 0.6 to 12.3 m 3 ha - 1 year - 1 , and 0.8 -6.4 t ha - 1 year - 1 Europe and gradually decrease towards the North, South, West and East. In most countries coniferous forests show larger increment estimates per hectare than broadleaved forests while mixed forests are at an intermediate level. However, in some instances, the differences were small or mixed forests revealed the largest increment , of volume and above -ground biomass, respectively. The largest increment estimates are found in Central estimates. The most important tree species groups in the study area are Pinus spp. and Picea spp., contributing 29% and 26% of the estimated total GAI volume, respectively. The shares of the prevalent broadleaved species are smaller with contributions of 9%, 7% and 6% by Quercus spp., Fagus sylvatica and Betula spp. The results underline the importance of harmonisation in international forest statistics. Looking ahead, harmonised largearea increment estimation is pivotal for accurate monitoring and evidence -based policy decisions in the changing context of future forest ecosystems dynamics, management strategies and wood availability.
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| 10. |
- Westerlund, Tommy, et al.
(författare)
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Community pharmacy and primary health care in Sweden-at a crossroads
- 2020
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Ingår i: Pharmacy Practice. - : Centro Investigaciones & Publicaciones Farmaceuticas. - 1885-642X .- 1886-3655. ; 18:2, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The overall goal of Swedish health care is good health and equitable care for the whole population. The responsibility for health is shared by the central government, the regions, and the municipalities. Primary care accounts for approximately 20 percent of all expenditures on health care. About 16% of all physicians work in primary health. The regions have also employed a large number of clinical pharmacists, usually hospital-based, but many perform a variety of different primary care services, the most common of which is patient medication reviews. Swedish primary health care is at a crossroads facing extensive challenges, due to changes in demography and demanding financial conditions. These changes necessitate large transformations in health services and delivery. Current Government inquiries have primarily focused on two ways to meet the challenges; a shift towards more local care requiring a transfer of resources from hospital care, and a further development of structured digi-physical care, that is both digital (“online doctors”) and physical accessibility of care. While primary care at present is undergoing processes of change, community pharmacy has done so during the past decade since the re-regulation of the Swedish pharmacy market. A monopoly was replaced by a competitive system, where five pharmacy chains now share most of the market, a competition that has made community pharmacy very commercialized. A number of different, promising primary care services are being offered, but they are usually delivered on a small scale due to a lack of remuneration and philosophy of providers. Priority is given to sales and fast dispensing of prescriptions, often with a minimum of counseling. Reflecting primary health care, community pharmacy in Sweden is at a crossroads but currently has a golden opportunity to choose a route of collaboration with primary health care in its current transformation into more local and digiphysical care. A major challenge is that primary health care inquires, strategic plans, and national policy documents usually do not include community pharmacy as a partner. Hence, community pharmacy have to be proactive and seize this chance of changes in primary health policy and organization in order to become an important link in the chain of health care delivery, or there is a significant risk that it will predominantly remain a retail business. © 2020, Grupo de Investigacion en Atencion Farmaceutica. All rights reserved.
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