Search

The report is Denmark’s National Inventory Report 2023, which serves as documentation for the Danish greenhouse gas inventories submitted to the European Union and the United Nations. The report contains information on Denmark’s emission inventories for all years’ from 1990 to 2021 for CO2, CH4, N2O, HFCs, PFCs and SF6.

Quercus robur/Quercus petraea and Pinus sylvestris are widely distributed and economically important tree species in Europe co-occurring on mesotrophic, xeric and mesic sites. Increasing dry conditions may reduce their growth, but growth reductions may be modified by mixture, competition and site conditions. The annual diameter growth in monospecific and mixed stands along an ecological gradient with mean annual temperatures ranging from 5.5 degrees C to 11.5 degrees C was investigated in this study. On 36 triplets (108 plots), trees were cored and the year-ring series were cross-dated, resulting in year-ring series of 785 and 804 trees for Q. spp. and P. sylvestris, respec-tively. A generalized additive model with a logarithmic link was fit to the data with random effects for the intercept at the triplet, year and tree level and a random slope for the covariate age for each tree; the Tweedie-distribution was used. The final model explained 87 % of the total variation in diameter increment for both tree species. Significant covariates were age, climate variables (long-term mean, monthly), local competition vari-ables, relative dbh, mixture, stand structure and interactions thereof. Tree growth declined with age and local density and increased with social position. It was positively influenced by mixture and structural diversity (Gini coefficient); mixture effects were significant for P. sylvestris only. The influence of potential evapotranspiration (PET) in spring and autumn on tree growth was positive and non-linear, whereas tree growth sharply decreased with increasing PET in June, which proved to be the most influential month on tree growth along the whole ecological gradient. Interactions of PET with tree social position (relative dbh) were significant in July and September for Q. spp. and in April for P. sylvestris. Interactions of climate with density or mixture were not significant. Climatic effects found agree well with previous results from intra-annual growth studies and indicate that the model captures the causal factors for tree growth well. Furthermore, the interaction between climate and relative dbh might indicate a longer growth duration for trees of higher social classes. Analysis of random effects across time and space showed highly dynamic patterns, with competitive advantages changing annually between species and spatial patterns showing no large-scale trends but pointing to the prevalence of local site factors. In mixed-species stands, the tree species have the same competitivity in the long-term, which is modified by climate each year. Climate warming will shift the competitive advantages, but the direction will be highly site-specific.

De danske skove har mange forskelligartede funktioner og opfylder derformange behov for samfundet. Skovene leverer træ til industrien ogbrændeovnen, indeholder en væsentlig del af den danske natur og tilbydersamtidig oplevelser til befolkningen. Skovenes mangfoldige funktionermedfører, at der er en stor opmærksomhed på deres artssammensætning,struktur, udvikling og anvendelse.Skovstatistik 2021 beskriver skovenes areal, vedmasse og kulstoflager samttilvækst og hugst. Derudover beskrives skovenes artssammensætning,struktur og udvikling i forhold til sundhed, biodiversitet, beskyttendefunktioner og samfundsøkonomiske forhold. Disse opgøres i forhold tilinternationalt anvendte indikatorer for bæredygtig skovforvaltning.Danmarks Skovstatistik udføres af Institut for Geovidenskab og Naturforvaltning,Københavns Universitet, for Miljøstyrelsen, Miljø- ogFødevareministeriet.

Quercus robur/Quercus petraea and Pinus sylvestris are widely distributed and economically important tree species in Europe co-occurring on mesotrophic, xeric and mesic sites. Increasing dry conditions may reduce their growth, but growth reductions may be modified by mixture, competition and site conditions. The annual diameter growth in monospecific and mixed stands along an ecological gradient with mean annual temperatures ranging from 5.5 °C to 11.5 °C was investigated in this study. On 36 triplets (108 plots), trees were cored and the year-ring series were cross-dated, resulting in year-ring series of 785 and 804 trees for Q. spp. and P. sylvestris, respectively. A generalized additive model with a logarithmic link was fit to the data with random effects for the intercept at the triplet, year and tree level and a random slope for the covariate age for each tree; the Tweedie-distribution was used. The final model explained 87 % of the total variation in diameter increment for both tree species. Significant covariates were age, climate variables (long-term mean, monthly), local competition variables, relative dbh, mixture, stand structure and interactions thereof. Tree growth declined with age and local density and increased with social position. It was positively influenced by mixture and structural diversity (Gini coefficient); mixture effects were significant for P. sylvestris only. The influence of potential evapotranspiration (PET) in spring and autumn on tree growth was positive and non-linear, whereas tree growth sharply decreased with increasing PET in June, which proved to be the most influential month on tree growth along the whole ecological gradient. Interactions of PET with tree social position (relative dbh) were significant in July and September for Q. spp. and in April for P. sylvestris. Interactions of climate with density or mixture were not significant. Climatic effects found agree well with previous results from intra-annual growth studies and indicate that the model captures the causal factors for tree growth well. Furthermore, the interaction between climate and relative dbh might indicate a longer growth duration for trees of higher social classes. Analysis of random effects across time and space showed highly dynamic patterns, with competitive advantages changing annually between species and spatial patterns showing no large-scale trends but pointing to the prevalence of local site factors. In mixed-species stands, the tree species have the same competitivity in the long-term, which is modified by climate each year. Climate warming will shift the competitive advantages, but the direction will be highly site-specific., The authors thank the European Union for funding the project “Mixed species forest management. Lowering risk, increasing resilience (REFORM)” under the framework of Sumforest ERA-NET. All contributors thank their national funding institutions to establish, measure and analyze data from the triplets. The Polish State Forests Enterprise also supported one of the Polish co-authors (Grant No: OR.271.3.15.2017). The Orléans site, OPTMix was installed thanks to ONF (National Forest Service, France), belongs to research infrastructure ANAEE-F; it is also included in the SOERE TEMPO, ZAL (LTSER Zone Atelier Loire) and the GIS oop network. This work was also supported by grant APVV-18-0347 (Slovakia). We acknowledge Institutional support MZE-RO0118 from the Ministry of Agriculture of the Czech Republic, partly funding the field measurements at Czech triplets.

The report is Denmark’s National Inventory Report 2022, which serves as documentation for the Danish greenhouse gas inventories submitted to the European Union and the United Nations. The report contains information on Denmark’s emission inventories for all years’ from 1990 to 2020 for CO2, CH4, N2O, HFCs, PFCs and SF6.

I denne rapport beskrives biogene byggematerialer og deres anvendelse til bærende konstruktioner som bjælker, søjler, skiver og præfabrikerede elementer, men også til bygningsdele som beklædning, overflader, tagdækning, isoleringsmaterialer for varme, lyd og brand; som kapillarbrydende materialer, armering i puds og plader, aptering og interiør. Specielt vil egenskaber med hensyn til nedbrydning, fugt, brand og lyd blive beskrevet, ligesom muligheder for ændring af egenskaber, oparbejdning og industriel fremstilling af byggematerialer behandles. The report describes opportunities and challenges in the use of biogenic resources for construction materials in Denmark. The report examines the possibilities of using biogenic materials in construction and at the consequences associated with growing, harvesting and producing building materials nationally. The report further sheds light on the potentials and barriers that can be identified by increasing the use of biogenic materials in construction in Denmark. Based on an assessment of the need for materials, both types and quantities, and the time horizon with which the materials in the required qualities and quantities can be ready as a resource. The assessments are performed as scenarios. The report shows that the construction can store carbon from atmospheric CO2 in the new construction corresponding to more than the total CO2 emissions from the entire current Danish consumption of concrete. In addition, the biogenic materials will be able to replace conventional building materials such as concrete, steel, brick, and mineral wool to a large extent which will reduce the CO2 emissions related to the production of these materials. In addition, the report highlights and shows buildings where biogenic materials have been used. A review of available biogenic resources shows a great potential for an extensive production of biogenic materials that can be used in construction from forestry, agriculture, and marine environments in Denmark. Resources that are renewable and can be grown and harvested annually from the same land. Furthermore, the report shows that pure fractions of wood biomass can meet a large part of the material requirements for a number of building materials other than materials for load-bearing structures. Supplemented with, for example, straw, the report shows that the need for sheet materials and insulation in construction, both high- and low-rise buildings, can be met by Danish production alone. It is also shown that materials for the load-bearing structures necessitate the import of, for example, construction wood, but can be reduced by greater Danish processing of inferior fractions of wood, which are currently not used for construction wood, for use in glulam or CLT elements. Furthermore, the use of biogenic materials for constructions can be increased by increasing knowledge of the materials and their properties. This is closely related to material knowledge in the construction value and supply chain. The value and supply chain must be familiar with the use of biogenic materials in construction, among other material suppliers, builders, architects, engineers, authorities, construction workers, builders, and users. Further, technical documentation of material properties including product specific EPDs for assessing the suitability of a material for a given function in a building and the assessment of greenhouse gas emissions must be based on facts. Both for the building owner, contractor, craftsman, supplier but also in relation to the government services and in the finance and insurance industry. Knowledge of construction technical solutions that have been tested before can increase knowledge of the materials’ performance and help to develop and improve the solutions in the short term. Knowledge can be accumulated through publicly accessible transparent lighthouse constructions where the economic, practical, design and execution experiences are shared in the construction industry. Knowledge that in this way can be anchored in society as a whole and implemented in educations of the construction supply chain by actors, from craftsmen to scientists, as well as the environments around the cultivation of biogenic materials in Denmark.

Heterogeneity of structure can increase mechanical stability, stress resistance and resilience, biodiversity and many other functions and services of forest stands. That is why many silvicultural measures aim at enhancing structural diversity. However, the effectiveness and potential of structuring may depend on the site conditions. Here, we revealed how the stand structure is determined by site quality and results from site-dependent partitioning of growth and mortality among the trees. We based our study on 90 mature, even-aged, fully stocked monocultures of Scots pine (Pines sylvestris L.) sampled in 21 countries along a productivity gradient across Europe. A mini-simulation study further analyzed the site-dependency of the interplay between growth and mortality and the resulting stand structure. The overarching hypothesis was that the stand structure changes with site quality and results from the site-dependent asymmetry of competition and mortality.First, we show that Scots pine stands structure across Europe become more homogeneous with increasing site quality. The coefficient of variation and Gini coefficient of stem diameter and tree height continuously decreased, whereas Stand Density Index and stand basal area increased with site index.Second, we reveal a site-dependency of the growth distribution among the trees and the mortality. With increasing site index, the asymmetry of both competition and growth distribution increased and suggested, at first glance, an increase in stand heterogeneity. However, with increasing site index, mortality eliminates mainly small instead of all-sized trees, cancels the size variation and reduces the structural heterogeneity.Third, we modelled the site-dependent interplay between growth partitioning and mortality. By scenario runs for different site conditions, we can show how the site-dependent structure at the stand level emerges from the asymmetric competition and mortality at the tree level and how the interplay changes with increasing site quality across Europe.Our most interesting finding was that the growth partitioning became more asymmetric and structuring with increasing site quality, but that the mortality eliminated predominantly small trees, reduced their size variation and thus reversed the impact of site quality on the structure. Finally, the reverse effects of mode of growth partitioning and mortality on the stand structure resulted in the highest size variation on poor sites and decreased structural heterogeneity with increasing site quality. Since our results indicate where heterogeneous structures need silviculture interventions and where they emerge naturally, we conclude that these findings may improve system understanding and modelling and guide forest management aiming at structurally rich forests.

Wood resources have been essential for human welfare throughout history. Also nowadays, the volume of growing stock (GS) is considered one of the most important forest attributes monitored by National Forest Inventories (NFIs) to inform policy decisions and forest management planning. The origins of forest inventories closely relate to times of early wood shortage in Europe causing the need to explore and plan the utilisation of GS in the catchment areas of mines, saltworks and settlements. Over time, forest surveys became more detailed and their scope turned to larger areas, although they were still conceived as stand-wise inventories. In the 1920s, the first sample-based NFIs were introduced in the northern European countries. Since the earliest beginnings, GS monitoring approaches have considerably evolved. Current NFI methods differ due to country-specific conditions, inventory traditions, and information needs. Consequently, GS estimates were lacking international comparability and were therefore subject to recent harmonisation efforts to meet the increasing demand for consistent forest resource information at European level. As primary large-area monitoring programmes in most European countries, NFIs assess a multitude of variables, describing various aspects of sustainable forest management, including for example wood supply, carbon sequestration, and biodiversity. Many of these contemporary subject matters involve considerations about GS and its changes, at different geographic levels and time frames from past to future developments according to scenario simulations. Due to its historical, continued and currently increasing importance, we provide an up-to-date review focussing on large-area GS monitoring where we i) describe the origins and historical development of European NFIs, ii) address the terminology and present GS definitions of NFIs, iii) summarise the current methods of 23 European NFIs including sampling methods, tree measurements, volume models, estimators, uncertainty components, and the use of air-and space-borne data sources, iv) present the recent progress in NFI harmonisation in Europe, and v) provide an outlook under changing climate and forest-based bioeconomy objectives.

Dansk kraft-varmeproduktion har gennemgået en omfattende omstilling gennem de sidste 30 år. Fra fossile energikilder som kul og naturgas til fornybare ressourcer som biomasse, vind- og solenergi. Biomasse fra skovene bidrager med en stor andel af det samlede forbrug af vedvarende energikilder, men der er stillet videnskabeligt spørgsmålstegn ved skovbiomassens bidrag til imødegåelse af klimaforandringer som følge af den tidsmæssige forskel mellem udledningen og genoptaget af CO2 når træbiomassen bruges til energi samt ved risikoen for skovødelæggelse som følge af brugen af bioenergi. I henhold til Klimaloven fra 2020 er Energistyrelsen forpligtiget til årligt at rapportere Danmarks forbrugsbaserede udledninger af klimagasser. Formålet med denne rapport er at estimere nettoudledningerne af CO2, der kan henføres til forbruget af biomasse fra skov til energiformål, til brug for Energistyrelsens Global Afrapportering 2022, Analysen er opdelt i tre delanalyser.1. analyser af et enkelt års udledning fra forbruget af biomasse fra skov til energiformål og af hvor hurtigt den biogene del af udledningerne genoptages i skoven 2. analyser af den samlede biogene nettoudledning CO2 til atmosfæren fra forbruget af biomasse fra skov til energiformål opdelt på flis og træpiller med et kontinuerligt forbrug over 100 år.3. analyser af den samlede biogene nettoudledning af CO2 til atmosfæren fra forbruget af biomasse fra skov til energiformål for hele det danske forbrug af træpiller og træflis med et kontinuerligt forbrug over 100 år. Analysen omfatter omregning til effekten på jordens opvarmning - ”Absolute Global Warming Potential” (AGWP).