Skogsdata 2022. Tema: Den formellt skyddade skogen

SLU Riksskogstaxeringen samlar årligen in data i skog och mark i Sverige som underlag för Sveriges officiella statistik om ”Skogarnas tillstånd och förändring”. Riksskogstaxeringen påbörjades redan 1923 och har sedan dess utvecklats såväl avseende vilka geografiska områden som ingår i inventeringen, som vad som inventeras. Från och med år 2003 inkluderades formellt skyddade områden inom nationalparker och naturreservat i fältinventeringen och från och med 2016 även de delar av fjällområdet som kan förväntas innehålla trädvegetation. Genom att utnyttja Naturvårdsverkets digitala georefererade information om gränser för formellt skyddade områden kan vi nu beskriva karaktärer och egenskaper för Sveriges formellt skyddade skogsmark. SCB publicerar årligen officiell statistik avseende arealer formellt skyddad skog i Sverige (SCB 2021). I detta temanummer fokuserar vi därför på att beskriva hur dessa arealer fördelas på olika egenskaper samt kvantifierar och beskriver egenskaper för virkesförråd, tillväxt och naturlig avgång. Vi jämför även tillstånd och egenskaper för skog inom formellt skyddade områden med övrig skog

Integrated calibration noise coupler for room temperature SKA band 1 feed system

This paper presents design of a novel coupler for the injection of calibration signal into the RF path of the SKA Band 1 quad-ridged flared horn, covering frequencies from 350–1050 MHz. The coupler is integrated in the feed horn and provides a coupling factor of −35 dB. The calibration signal is injected before the first amplification stage, without any degradation in the noise performance of the room temperature system

Diversities and similarities in PFGE profiles of Campylobacter jejuni isolated from migrating birds and humans

Aims: To genetically sub-type Campylobacter jejuni strains isolated from migratory birds, and to compare these with clinical strains collected in the same area and corresponding time period, with the aim to increase our knowledge on sub-types occurring among wild birds and their possible impact on human disease. Methods and Results: We sub-typed C. jejuni strains from migrating birds (n = 89) and humans (n = 47), using macrorestriction profiling by pulsed-field gel electrophoresis. Isolates from migrant birds often exhibited sub-types with higher levels of similarity to isolates from birds of the same species or feeding guild, than to isolates from other groups of birds. Likewise, could the vast majority of sub-types found among the migrant bird isolates not be identified among sub-types from human cases. Only two bird strains, one from a starling (Sturnus vulgaris) and one from a blackbird (Turdus merula), had sub-types that were similar to some of the human strain sub-types. Conclusions: Isolates from one bird species, or feeding guild, often exhibited high similarities, indicating a common transmission source for individuals, or an association between certain sub-types of C. jejuni and certain ecological guilds or phylogenetic groups of birds. Sub-types occurring among wild birds were in general distinctively different from those observed in patients. The two bird isolates that were similar to human strains were isolated from bird species that often live in close associations with human settlements. Significance and Impact of Study: Wild birds have often been mentioned as a potential route for transmission of C. jejuni to humans. Our study demonstrates that strains isolated from birds most often are different from clinical strains, but that some strain similarities occur, notably in birds strongly associated with human activities

Divergent occurrences of juvenile and adult trees are explained by both environmental change and ontogenetic effects

Recent climate warming has fueled interest into climate-driven range shifts of tree species. A common approach to detect range shifts is to compare the divergent occurrences between juvenile and adult trees along environmental gradients using static data. Divergent occurrences between life stages can, however, also be caused by ontogenetic effects. These include shifts of the viable environmental conditions throughout development (?ontogenetic niche shift') as well as demographic dependencies that constrain the possible occurrence of subsequent life stages. Whether ontogenetic effects are an important driver of divergent occurrences between juvenile and adult trees along large-scale climatic gradients is largely unknown. It is, however, critical in evaluating whether impacts of environmental change can be inferred from static data on life stage occurrences. Here, we first show theoretically, using a two-life stage simulation model, how both temporal range shift and ontogenetic effects can lead to similar divergent occurrences between adults and juveniles (juvenile divergence). We further demonstrate that juvenile divergence can unambiguously be attributed to ontogenetic effects, when juveniles diverge from adults in opposite direction to their temporal shift along the environmental gradient. Second, to empirically test whether ontogenetic effects are an important driver of divergent occurrences across Europe, we use repeated national forest inventories from Sweden, Germany and Spain to assess juvenile divergence and temporal shift for 40 tree species along large-scale climatic gradients. About half of the species-country combinations had significant juvenile divergences along heat sum and water availability gradients. Only a quarter of the tree species had significant detectable temporal shifts within the observation period. Furthermore, significant juvenile divergences were frequently associated with opposite temporal shifts, indicating that ontogenetic effects are a relevant cause of divergent occurrences between life stages. Our study furthers the understanding of ontogenetic effects and challenges the practice of inferring climate change impacts from static data.Universidad de AlcaláMinisterio de Ciencia e InnovaciónAgencia Estatal de Investigació

Taller and slenderer trees in Swedish forests according to data from the National Forest Inventory

Changes over time in annual basal area growth and mean height for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) over the period, 1983-2020 were studied using sample tree data from temporary plots recorded in the Swedish National Forest Inventory. The annual basal area growth was derived from the last measured full ring on increment cores. Using 20 to 60-year-old dominant trees, the mean height and annual basal area growth were examined as functions of tree, stand and site conditions, and trends were assessed mainly using residual analyses over time. A significant increase in mean height at a given age was found for both species, but the annual basal area growth level remained stable over the 38-year period. Currently, at a given age of 50 annual rings at breast height, the mean heights of pines and spruces increased on average by 10.1% (i.e. similar to 2 m), compared to 50 year-old pines and spruces in the 1980s, and the increase was similar in the different regions. The results suggest that trees have become taller and slenderer in Swedish forests. Increasing tree height over time at a given age in Northern Europe has been documented in several reports and many causes have been suggested, such as changed forest management, increasing temperatures and nitrogen deposition. We suggest that elevated CO2 in the air and improved water-use efficiency for the trees might also be strong drivers

Underestimation of boreal soil carbon stocks by mathematical soil carbon models linked to soil nutrient status

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Ultra-wideband feed systems for the EVN and SKA - evaluated for VGOS

The design of the Square Kilometre Array (SKA) project for radio astronomy is now materializing at a rapid speed; the EU Horizon 2020 RadioNet project BRoad-bAND (BRAND) has the ambition to deliver a decade bandwidth receiver for EVN. The ultra-wideband quad-ridge flared horn (QRFH) feed systems developed for these projects show good performance within the geodetic VLBI Global Observing System (VGOS) frame due to the overlapping frequency bands and reflector geometries. We estimate, through simulation, system equivalent flux density (SEFD) of the two feed systems in the VGOS reflector and compare the it to the existing system installed on one of the 13.2 m diameter reflectors of the Onsala twin telescope (OTT). The two frequency bands analyzed cover 1.5−15.5 GHz and 4.6−24 GHz. Both systems show SEFD better than 1000 Jy over large parts of resp. frequency band - comparable to the 3−18 GHz feed systems. For the SKA QRFH over 4.6−24 GHz, the water vapor absorption line at 22 GHz is within the operational band, therefore we study the application of water-vapor radiometry in line-of-sight of the telescope

Wideband single pixel feed system over 4.6-24 GHz for the Square Kilometre Array

We present the Band B feed system over 4.6-24 GHz designed for the Square Kilometre Array (SKA) reflector for radio astronomy applications. The feed is a Quad-ridge Flared Horn (QRFH) with a customized shape based on spline-defined profiles to achieve improved wideband performance. The feed system shows high aperture efficiency and sensitivity on the SKA reflector in predictions based on measured feed beam patterns. We present the feed design overview, cryogenic dewar concept and measurement of receiver noise (10-20 K) with wideband low-noise amplifiers, and full system simulation of the performance

Onsala Space Observatory – IVS Technology Development Center Activities during 2017–2018

We give a brief overview of the technical development related to geodetic VLBI done during 2017 and 2018 at the Onsala Space Observatory

Complementarity effects on tree growth are contingent on tree size and climatic conditions across Europe

Although sustainable development was defined in the Brundtland Report almost 30 years ago, the current usage of the concepts of sustainability and sustainable development remain highly equivocal. In the context of rural communities, multiple interpretations and weak definitions lead to confusion in understanding what comprises a sustainable rural community. Building on existing definitions (e.g. Baker's, 2006, ‘Ladder of Sustainable Development'), models (principally, The Egan Review's, 2004, ‘Components of Sustainable Communities') and findings of this study, a sustainable community is defined and a holistic model of a sustainable place-based rural community is presented. This model, the sustainable community design (SCD) is used as the basis for analysing community sustainability, which is measured using mixed methods and scorecard assessment. Sensitivity of the method is demonstrated with inter- and intra-community variations in sustainability across three diverse Scottish rural communities. Intra-community variations illustrate heterogeneity in community sustainability, explain ambiguity in characterisations of an individual community's sustainability, and highlight the importance of an interdisciplinary and holistic approach to community development. The SCD framework is presented as a useful tool for meso-level sustainability assessment and to facilitate the sustainable development of rural communities