Enterprise Liability, Public and Private

In Sweden, where forests cover more than 60% of the land area, silviculture and the use of forest products by industry and society play crucial roles in the national carbon balance. A scientific challenge is to understand how different forest management and wood use strategies can best contribute to climate change mitigation benefits. This study uses a set of models to analyze the effects of different forest management and wood use strategies in Sweden on carbon dioxide emissions and removals through 2105. If the present Swedish forest use strategy is continued, the long-term climate change mitigation benefit will correspond to more than 60 million tons of avoided or reduced emissions of carbon dioxide annually, compared to a scenario with similar consumption patterns in society but where non-renewable products are used instead of forest-based products. On average about 470 kg of carbon dioxide emissions are avoided for each cubic meter of biomass harvested, after accounting for carbon stock changes, substitution effects and all emissions related to forest management and industrial processes. Due to Sweden’s large export share of forest-based products, the climate change mitigation effect of Swedish forestry is larger abroad than within the country. The study also shows that silvicultural methods to increase forest biomass production can further reduce net carbon dioxide emissions by an additional 40 million tons of per year. Forestry’s contribution to climate change mitigation could be significantly increased if management of the boreal forest were oriented towards increased biomass production and if more wood were used to substitute fossil fuels and energy-intensive materials

Evaluation of individual-tree growth models for Picea abies based on a case study of an uneven-sized stand in southern Sweden

To develop recommendations for tree selection in Continuous Cover Forestry (CCF), access to valid tools for simulating growth at individual tree-level is necessary. To assist efforts to develop such tools, in this study, long-term observation data from two uneven-sized Norway spruce plots in southern Sweden are used to evaluate old and new individual-tree growth models (two established Swedish models, two new preliminary models and included as a reference, a Finnish model). The plots' historical management records and site conditions are the same, but their last thinning treatment differs. Observed diameter increment at tree-level is investigated in relation to treatment. Individual tree growth residuals of tested models are evaluated in relation to tree diameter, treatment, projection length and sensitivity to the predictor mean stand age. Furthermore, the relations between displayed residuals and basal area local competition are analysed. The analyses indicate that active thinning made annual diameter increment independent of tree diameter above a threshold level, while the absence of thinning supported a concave relationship. All tested models displayed a significant linear bias leading to overestimation of small trees' growth and increasing underestimations of larger trees' growth with tree diameter. All distance-independent models displayed residual trends related to local competition

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Carbon Balance Implications Of Forest Biomass Production Potential

Forests in boreal and temperate forest-ecosystems have an important function since they sequester atmospheric carbon by uptake of carbon-dioxide in photosynthesis, and transfer and store carbon in the forest ecosystem. Forest material can be used for bio-fuel purposes and substitute fossil fuels, and supply wood products, which can replace carbon- and energy-intensive materials. Therefore it is vital to consider the role of forests regarding today´s aim to mitigate climate change. This thesis assess (i) how climate change affects future forest carbon balance, (ii) the importance of different strategies for forest management systems, and biomass production for the carbon balance, (iii) how the use of forest production affect the total carbon balance in a lifecycle perspective, and (iv) how the Swedish carbon balance is affected from the standpoint of both the actual use of forest raw material within Sweden and what Swedish forestry exports. The analysis was made mainly in a long-term perspective (60-300 year) to illustrate the importance of temporal and also the spatial perspective, as the analysis includes stand level, landscape level, and national level. In this thesis, forestry was considered a system. All activities, from forest regeneration to end use of forest products, were entities of this system. In the evaluation, made from a systems perspective, we used life-cycle analysis to estimate carbon stock in different system flows. Different forest management systems and forest production were integrated in the analyses. Different forest management scenarios were designed for the Swedish forest management in combination with the effect of future climate change; (i) intensive forest practice aiming at increased growth, (ii) increased forest set-aside areas, changes in forest management systems for biomass production, and (iii) how the use of forest production affect the total carbon balance (construction material, bioenergy and other domestic use). The results showed that future climate changes and intensive forest management with increased production could increase the biomass production and the potential use of forest raw material. This has a positive effect on carbon storage for the forest carbon stock, litter production and carbon storage in the ground etc. and help mitigating carbon-dioxide. Increased forest set-aside areas can increase the short-term carbon stock in forest ecosystems, but will reduce the total long-term carbon balance. The net carbon balance for clear-cut forestry did not differ significantly from continuous-cover forestry, but was rather a question of level of growth. Most important, in the long term, was according to our analysis, how forest raw material is used. Present Swedish forestry and use of forest raw material, both within Sweden and abroad, reduce carbon-dioxide emissions and mitigate climate change. The positive effect for the total carbon balance and climate benefit take place mostly abroad, due to the Swedish high level of export of wood products and the higher substitution effects achieved outside Swedish borders. One strategy is to increase production, harvest and change the use of Swedish forest raw material to replace more carbon intensive material, which can contribute to significant emission reduction. Carbon-dioxide mitigation, as a result of present Swedish forestry, was shown to be almost of the same level as the total yearly emission of greenhouse gases. The total carbon benefit would increase if the biomass production and felling increased and if Swedish wood products replaced carbon intensive materials.This thesis shows also that, by changing forest management, increase the growth and the use of forest raw material and export of forest material we can contribute to even larger climate benefits. In a long-term perspective, the substitution effects and replacement of carbon- and energy-intensive materials are of greater significance than carbon storage effects in forests. A more production oriented forestry needs to make balances and increase the prerequisite for biological diversity, improve recreation possibilities, and protect sensitive land areas and watersheds.Climate benefits, from Swedish forestry, are highly dependent on policy decision-making and how that can steer the direction for the Swedish forestry

Forest biomass production potential and its implications for carbon balance

An integrated methodological approach is used to analyse the forest biomass production potential in the Middle Norrland region of Sweden, and its use to reduce carbon emissions. Forest biomass production, forest management, biomass harvest, and forest product use are analyzed in a system perspective considering the entire resource flow chains. The system-wide carbon flows as well as avoided carbon emissions are quantified for the activities of forest biomass production, harvest, use and substitution of non-biomass materials and fossil fuels. Five different forest management scenarios and two biomass use alternatives are developed and used in the analysis. The analysis is divided into four main parts. In the first part, plant biomass production is estimated using principles of plant-physiological processes and soil-water dynamics. Biomass production is compared under different forest management scenarios, some of which include the expected effects of climate change based on IPCC B2 scenario. In the second part, forest harvest potentials are estimated based on plant biomass production data and Swedish national forest inventory data for different forest management alternatives. In the third part, soil carbon stock changes are estimated for different litter input levels from standing biomass and forest residues left in the forest during the harvest operations. The fourth and final part is the estimation of carbon emissions reduction due to the substitution of fossil fuels and carbon-intensive materials by the use of forest biomass. Forest operational activities such as regeneration, pre-commercial thinning, commercial thinning, fertilisation, and harvesting are included in the analysis. The total carbon balance is calculated by summing up the carbon stock changes in the standing biomass, carbon stock changes in the forest soil, forest product carbon stock changes, and the substitution effects. Fossil carbon emissions from forest operational activities are calculated and deducted to calculate the net total carbon balance.The results show that the climate change effect most likely will increase forest biomass production over the next 100 years compared to a situation with unchanged climate. As an effect of increased biomass production, there is a possibility to increase the harvest of usable biomass. The annual forest biomass production and harvest can be further increased by the application of more intensive forestry practices compared to practices currently in use. Deciduous trees are likely to increase their biomass production because of climate change effects whereas spruce biomass is likely to increase because of implementation of intensive forestry practices.IIIntensive forestry practices such as application of pre-commercial thinning, balanced fertilisation, and introduction of fast growing species to replace slow growing pine stands can increase the standing biomass carbon stock. Soil carbon stock increase is higher when only stem-wood biomass is used, compared to whole-tree biomass use. The increase of carbon stocks in wood products depends largely on the magnitude of harvest and the use of the harvested biomass. The biomass substitution benefits are the largest contributor to the total carbon balance, particularly for the intensive forest management scenario when whole-tree biomass is used and substitutes coal fuel and non-wood construction materials. The results show that the climate change effect could provide up to 104 Tg carbon emissions reduction, and intensive forestry practices may further provide up to 132 Tg carbon emissions reduction during the next 100 years in the area studied.This study shows that production forestry can be managed to balance biomass growth and harvest in the long run, so that the forest will maintain its capacity to increase standing biomass carbon and provide continuous harvests. Increasing standing biomass in Swedish managed forest may not be the most effective strategy to mitigate climate change. Storing wood products in building materials delays the carbon emissions into the atmosphere, and the wood material in the buildings can be used as biofuel at the end of a building life-cycle to substitute fossil fuels.These findings show that the forest biomass production potential in the studied area increases with climate change and with the application of intensive forestry practices. Intensive forestry practice has the potential for continuous increased biomass production which, if used to substitute fossil fuels and materials, could contribute significantly to net carbon emissions reductions and help mitigate climate change

Forest management scenarios and their effects on ecosystem services : some analytical results from Sweden

Sweden has just more than 23 million hectares of productive forest, which has been actively managed for more than 100 years. This has led to one of the recognized forest products exporting country. Despite the vital role of forests in providing forest products in sustaining various human needs, there is an increasing demand for the inclusion of ecosystem services in forest planning decision making. Today, methods in conventional assessments on forest growth, yield and harvest are facing changes due to extended interests in the assessments on overall forestry systems effects on ecosystem services including carbon balance of the system. Recently, integrated approaches that have concepts of forest science, wood material science, energy science and cleaner productions have been used in the field of forestry to assess the important role of forestry in reducing carbon emissions. This paper uses a system analysis approach to perform a model based analysis that includes forest management and their effects on different indicators of ecosystem services in Swedish forest landscape

Carbon balance in production forestry in relation to rotation length

The choice of a rotation length is an integral part of even-aged forest management regimes. In this study, we have simulated stand development and carbon pools in four even-aged stands representing the two most common tree species in Fennoscandia, Norway spruce (Picea abies) and Scots pine (Pinus sylvestris), growing on high and low productive sites. We hypothesized that increased rotation lengths (+10, +20 and +30 years) in comparison with todayâ s practice would increase forestsâ average carbon stock during a rotation cycle, but decrease the average yield. The results showed that for spruce a moderate increase in rotation length (+10 years) increased both average standing carbon stock and average yield. For the longer alternatives (+20 and +30 years) for spruce and for all pine alternatives prolonging rotation lengths resulted in increased average standing carbon stocks but decreased average yield resulting in decreased carbon storage in forest products and decreased substitution effects. Decreasing the rotation lengths (-10 years) always resulted in both decreased average standing carbon stocks and decreased yields. We conclude that a moderate increase of rotation lengths may slightly increase forestsâ climate benefits for spruce sites but for all other alternatives there was a trade-off between the temporary gain of increasing carbon stocks and the permanent loss in productivity and consequently substitution potential.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author