Scandinavian Forest Research Articles

Under-Canopy Drone 3D Surveys for Wild Fruit Hotspot Mapping

Advances in mobile robotics and AI have significantly expanded their application across various domains and challenging conditions. In the past, this has been limited to safe, controlled, and highly structured settings, where simplifying assumptions and conditions allowed for the effective resolution of perception-based tasks. Today, however, robotics and AI are moving into the wild, where human–robot collaboration and robust operation are essential. One of the most demanding scenarios involves deploying autonomous drones in GNSS-denied environments, such as dense forests. Despite the challenges, the potential to exploit natural resources in these settings underscores the importance of developing technologies that can operate in such conditions. In this study, we present a methodology that addresses the unique challenges of natural forest environments by integrating positioning methods, leveraging cameras, LiDARs, GNSS, and vision AI with drone technology for under-canopy wild berry mapping. To ensure practical utility for fruit harvesters, we generate intuitive heat maps of berry locations and provide users with a mobile app that supports interactive map visualization, real-time positioning, and path planning assistance. Our approach, tested in a Scandinavian forest, refines the identification of high-yield wild fruit locations using V-SLAM, demonstrating the feasibility and effectiveness of autonomous drones in these demanding applications.

Quantify and account for field reference errors in forest remote sensing studies

Field inventoried data are often used as references (ground truth) in forest remote sensing studies. However, the reference values are affected by various kinds of errors, which tend to make the reported accuracies of the remote sensing-based predictions worse than they are. The more accurate the remote sensing techniques are becoming, the more pronounced this problem will be. This paper addresses the impact of uncertainties in field reference data due to measurement errors, model errors, and position errors when evaluating the accuracy of biomass predictions from airborne laser scanning at plot level. We present novel theoretical analysis methods that take the interactions of the error sources into account. Further, an error characterization model (ECM) is used to describe the error structure of the remote sensing-based predictions, and we show how the parameters of the ECM can be adjusted when field references contain errors. We also show how root mean square error (RMSE) estimates can be adjusted. Based on data from Scandinavian forests, we conclude that the field reference errors have an impact on the remote sensing-based predictions. By accounting for these errors the RMSE of the remote sensing-based predictions was reduced by 6–18%. The most influential sources of error in the field references were found to be the residual errors of the allometric biomass model and the field plot position errors. Together, these two sources accounted for 97% of the variance while measurement errors and biomass model parameter uncertainties were negligible in our study.

Scandinavian Forest Fire Activity Correlates with Proxies of the Baffin Bay Ice Cover

Understanding factors driving fire activity helps reveal the degree and geographical variability in the resilience of boreal vegetation to large scale climate forces. We studied the association between sea ice cover in the Baffin Bay and the Labrador Sea and observational records of forest fires in two Nordic countries (Norway and Sweden) over 1913–2017. We found a positive correlation between ice proxies and regional fire activity records suggesting that the Arctic climate and the associated changes in North Atlantic circulation exercise an important control on the levels of fire activity in Scandinavia. Changes in the sea cover are likely correlated with the dynamic of the North Atlantic Current. These dynamics may favor the development of the drought conditions in Scandinavia through promoting persistent high-pressure systems over the Scandinavian boreal zone during the spring and summer. These periods are, in turn, associated with an increased water deficit in forest fuels, leading to a regionally increased fire hazard. The Arctic climate will likely be an important future control of the boreal fire activity in the Nordic region.

Evaluation of biological nitrogen fixation in coarse woody debris from Eastern Canadian boreal forests

The contribution of Coarse Woody Debris (CWD) to N inputs in boreal ecosystems has been reported in intensively managed Scandinavian forests in Europe and in Pacific coastal rainforest in North America. These estimates range from 0.085 to 2 kg N ha−1 y−1. Data from Eastern Canadian forests that receive fewer sylvicultural treatments than do Scandinavian forests and are exposed to a drier climate than the Canadian rainforest are scare. We evaluated contributions of CWD to total BNF in two forest sites dominated by balsam fir and black spruce. We also measured the conversion ratio (R ratio = ARA/N2) for the acetylene reduction assay, which is the method most often used to estimate N2-fixation, using parallel 15N2 incubations to account for potential methodological biases. We further tested two factors that can affect the R ratio, hance quality of BNF estimates in deadwood; inhibition of N2-fixing methanotrophs by acetylene and molybdenum limitation of N2-fixation. We report that N2-fixation by CWD in balsam fir and black spruce from eastern boreal forest is low (0.05–0.12 kg N ha−1y−1) compared to other estimates for coniferous forests. We also show that moss-covered CWD can significantly contribute to CWD N2-fixation and that improper validation of the ARA can lead to significant underestimation of N inputs.

Effects of Warming on Shrub Abundance and Chemistry Drive Ecosystem-Level Changes in a Forest–Tundra Ecotone

Tundra vegetation is responding rapidly to on-going climate warming. The changes in plant abundance and chemistry might have cascading effects on tundra food webs, but an integrated understanding of how the responses vary between habitats and across environmental gradients is lacking. We assessed responses in plant abundance and plant chemistry to warmer climate, both at species and community levels, in two different habitats. We used a long-term and multisite warming (OTC) experiment in the Scandinavian forest–tundra ecotone to investigate (i) changes in plant community composition and (ii) responses in foliar nitrogen, phosphorus, and carbon-based secondary compound concentrations in two dominant evergreen dwarf-shrubs (Empetrum hermaphroditum and Vaccinium vitis-idaea) and two deciduous shrubs (Vaccinium myrtillus and Betula nana). We found that initial plant community composition, and the functional traits of these plants, will determine the responsiveness of the community composition, and thus community traits, to experimental warming. Although changes in plant chemistry within species were minor, alterations in plant community composition drive changes in community-level nutrient concentrations. In view of projected climate change, our results suggest that plant abundance will increase in the future, but nutrient concentrations in the tundra field layer vegetation will decrease. These effects are large enough to have knock-on consequences for major ecosystem processes like herbivory and nutrient cycling. The reduced food quality could lead to weaker trophic cascades and weaker top down control of plant community biomass and composition in the future. However, the opposite effects in forest indicate that these changes might be obscured by advancing treeline forests.

Can we separate the sinners from the scapegoats?

Despite the impression of doom and gloom concerning the fate of the world’s wildlife that one can gather from the media, there are in fact many success stories from recent decades where populations of various species have stabilized or recovered. However, learning to live with these conservation success stories is often harder than bringing about the initial recovery. European large carnivores are a case in point, especially the wolf (Canis lupus). Following the changes in public opinion and policy that began appearing in the 1970s, 1980s and 1990s, wolf populations have begun to recolonize many parts of Europe, such as Scandinavia, the French and Italian Alps, and the German lowlands, from which they had been absent for many decades. The response has been an explosion of conflict, both of a material and economic nature (caused mainly by depredation on livestock; Kaczensky, 1999) and of a social and political nature (focusing mainly on the symbolic aspects of this recovery; Skogen, Mauz & Krange, 2006; Dickman, 2010). The case of wolves also illustrates the diversity of conflicts that can emerge, that go far beyond the simple economic conflicts and into areas where perceptions are just as important as reality. Seals are a clear marine parallel to terrestrial wolves in both their conservation history and the range of conflicts that their conservation has produced, with salmon taking the place of sheep as the main victims, and farmers and hunters being replaced by fishermen of various types as the main protagonists. Addressing such conflicts, be they in Scottish estuaries, European mountains or Scandinavian forests, requires a three-step process. Firstly, there is a need to recognize the genuine existence of a conflict and the equal legitimacy of the diverse dimensions along which a conflict can be expressed. Secondly, there is a need to understand the functional mechanisms behind the conflict, including both the ecological and the sociological/political aspects. Only when these two steps have been completed is it possible to move onto the third step of identifying potential conflict reduction, mitigation or compensation measures. The paper by Graham et al. (2011) is a welcome contribution to the second step of this heuristic framework and is set in the context of the conflict between seals and salmon fishermen. Killing carnivores and seals is controversial with the public and may endanger their conservation status (Treves, 2009). Graham et al. (2011) seek to explore the evidence for the existence of problem individuals (sensu Linnell et al., 1999) among the seal population, which are responsible for a disproportional impact on salmon. The idea is that a more selective removal (i.e. killing) of these individuals, if they exist, would create less of a conflict with the public’s sensibilities and with seal conservation than a more widespread use of lethal control across the whole seal population. This testing of an underlying management assumption is a crucial step toward a robust and knowledge-based management system. In their paper, Graham et al. (2011) draw on multiple lines of evidence to indicate that there may well be some individuals that disproportionally make use of rivers and that seals in rivers feed more on salmon and trout than other seals. Taken in isolation, none of their data would be strong enough to draw conclusions. Their sample size for investigating seal diet is particularly small. However, when taken together, the multiple lines of evidence certainly present a strong case for the existence of problem, or ‘rogue’ seals, although there is clearly a need for more research on the topic. Comparative telemetry data from rogue and nonrogue seals would have been particularly interesting as it has often been used in comparative studies of terrestrial carnivores (e.g. Odden et al., 2002), as would the use of welldesigned adaptive management experiments where the impact of seal removal was monitored. The important question is how this new information is used in the context of seal management. This latest paper goes a long way to testing the assumption of the existence of rogue seals, which is part of the model presented earlier by Butler et al. (2006). However, there is still a little understanding of exactly how much time each rogue seal spends in the rivers, which will be crucial to understanding the potential impact on salmon runs of removing these individuals. This opens up for a fascinating and complex debate about the place of lethal control in conflict management of predatory mammals in general (Treves, 2009). On the one hand, lethal control is often used in the belief that removing certain individuals or a proportion of the population will actually achieve measurable changes (such as reduction in Animal Conservation. Print ISSN 1367-9430

Environmental change without climate change?

Environmental change without climate change?

Filíocht Nua: New Poetry

Filíocht Nua: New Poetry Jean O’Brien Snow Ciphers Ice crystals growing on threadbare trees are strange fruits of rime. Cold sun brings beauty to a cruel landscape, white has homogenised road and fields. Only the steaming black or brown coats of horses stand out in relief against a featureless backdrop. Lambs hurtle like tossed snowballs their mothers lost in the need to make milk. Birds rustle and break from every hedgerow. I gingerly inch past, robins, finches, blackbirds—even that tiny troglodyte the wren, all fluffed feathers, like dust-devils bowling along. Mostly we stay cooped up, locked in, braving the chill only to chip away at frozen coal, its burnished black stark against the almost monotonous white. Fog and grey skies menace and hang heavy, strange footprints ripen in the dark. [End Page 43] Scandinavian Dream The dead visit me in dreams as I lapse between consciousness and sleep, in that anteroom where dreams are hung waiting to be tried on. Lately my father has come to me, alive and well it seems after all. He now lives near some Scandinavian forest, in a bright log cabin. I see bark peel from the burnished wood and trees in the middle distance, a small clearing like a yard outside the door with honeysuckle growing under the eaves. I could describe this place enough to go there. The air here is light and suffused with motes that could be fireflies waiting for the dark to illuminate them. My father does not speak to me, (though he is sentient, I know) nor seem to notice I am here. He looks my way but his gaze goes through me. He rests on an upholstered chair. When he leans forward I see orange birds of paradise embroidered on the upright. The pattern looks out of place here where everything is pared down and uncomplicated. Even if he no longer knows me, I am glad I have seen him, and that he is content. Death suits him in some way. At daybreak my husband touches me. I leave the woods and wake to the summer cotton counterpane on our bed, the radio murmuring some unwelcome news. I fix my sleep-filled gaze on a trapped butterfly tapping its Morse unanswered on the window pane. [End Page 44] Out of His Element If he could fly he would go now to his spawning pool. Instead he lies drowning in air, his glistering scales dulling down. His eyes grow cold and flat clouding over, the leap and struggle ended. One leap too far and he landed on earth stranded on grass, the blue of sky fixed in him. He dreams of flashing through clear water, casting his sheen and shadow onto stones on the river bed. His gills heaving now as he draws air, lungs gulping for water. Web A single magpie flies sorrowfully by his black and white feathers intersecting with the colours of a fading rainbow. We see the spider and his web and he sees us as he sits an all-seeing eye at the centre of a world that radiates ’round him. His silk stretches from tree trunk to tall purple Allium, whose giant head nods in the breeze. I work around it tenderly, sensing its almost invisible presence, like a snagging doubt at the edge of consciousness, as I dig and plant, footing in the promise of summer blooms. The joyful second magpie joins its mate, their plumage stark in gathered evening light. Rain clears and small droplets snared in the web make it twinkle like evening star. I gather up my spade and hoe and move indoors. [End Page 45] Barefoot The long grass is swaying like the roll and swell of sea, plunging and windblown and watery green. Beached on a shelf a roller conch shell, pearly white, tinged with pink, an ear trumpet thumping out sounds of waves and the lap of water. I feel we are harvesting the sea. The end of the earth is marked by a child dragging a stick through shale at the place where it is swallowed by water. Looking out I see the dividing line between liquid blue and air blue...

The role of fire in southern Scandinavian forests during the late Holocene

Charcoal fragments preserved in small, wet basins are used to characterise the fire regime of temperate and mixed boreal forest (hemiboreal) zones of southern Scandinavia during the last 3500 years. There was far less charcoal recorded from the temperate zone than the hemiboreal zone during the last 3500 years, yet the low temperate zone values showed a clear trend of continuous increase until 1500 AD, after which the values decreased sharply. The record from the hemiboreal region showed a greater temporal variability with far higher charcoal influx values than in the temperate zone. There were significant positive correlations between charcoal influx and Betula, Calluna and Pinus pollen abundance and negative correlations with pollen indicators of anthropogenic impact such as Rumex and Cerealia. Charcoal influx in the temperate zone showed a strong association with the period of major anthropogenic impact, whereas the hemiboreal data reacted more to climatic change. The temporal and spatial pattern of charcoal influx was only a minor explanatory factor for vegetation composition at a regional scale in southern Scandinavia. The fire return interval was often long and irregular in most of the region and anthropogenic factors such as grazing, mowing and establishment of arable fields were probably more important than fire as drivers of vegetation change.

The charcoal carbon pool in boreal forest soils

Forest fires release significant amounts of carbon dioxide into the atmosphere, but also convert a fraction of the burning vegetation to charred black carbon. Examination of 845 soil samples in Scandinavian forests shows that the charcoal content of boreal soils is highly variable, and more susceptible to degradation than has been thought. Forest fires release significant amounts of carbon dioxide into the atmosphere1, but also convert a fraction of the burning vegetation to charred black carbon. Black carbon is hard to break down, and formation of this reserve therefore creates a long-term soil carbon sink2,3,4,5,6,7. However, although soil black carbon pools are important for global carbon budgets, the spatial variation and dynamics of these pools are poorly understood6,7,8,9. Here we examine the charcoal content of 845 soil samples collected from a broad range of boreal forest landscapes and climates in Scandinavia. We show that there is considerable variation in the distribution and carbon content of soil charcoal between forest landscapes; the landscape-level amount of soil carbon stored in charcoal ranged from 0 to 222 g C m−2, with an average of 77 g C m−2. The carbon concentration in the soil charcoal is significantly lower than that found in recently produced fresh charcoal, suggesting that charcoal carbon content decreases with time. Indeed, the median age of a subset of 14C-dated soil charcoal particles was 652 years, implying a rapid turnover compared with the expected median age of approximately 5,000 years if charcoal is persistent. Assuming that our measurements are representative of boreal forests worldwide, we estimate that boreal forest soils store 1 Pg of carbon in the form of charcoal, equivalent to 1% of the total plant carbon stock in boreal forests.

Towards operational remote sensing of forest carbon balance across Northern Europe

Abstract. Monthly averages of ecosystem respiration (ER), gross primary production (GPP) and net ecosystem exchange (NEE) over Scandinavian forest sites were estimated using regression models driven by air temperature (AT), absorbed photosynthetically active radiation (APAR) and vegetation indices. The models were constructed and evaluated using satellite data from Terra/MODIS and measured data collected at seven flux tower sites in northern Europe. Data used for model construction was excluded from the evaluation. Relationships between ground measured variables and the independent variables were investigated. It was found that the enhanced vegetation index (EVI) at 250 m resolution was highly noisy for the coniferous sites, and hence, 1 km EVI was used for the analysis. Linear relationships between EVI and the biophysical variables were found: correlation coefficients between EVI and GPP, NEE, and AT ranged from 0.90 to 0.79 for the deciduous data, and from 0.85 to 0.67 for the coniferous data. Due to saturation, there were no linear relationships between normalized difference vegetation index (NDVI) and the ground measured parameters found at any site. APAR correlated better with the parameters in question than the vegetation indices. Modeled GPP and ER were in good agreement with measured values, with more than 90% of the variation in measured GPP and ER being explained by the coniferous models. The site-specific respiration rate at 10°C (R10) was needed for describing the ER variation between sites. Even though monthly NEE was modeled with less accuracy than GPP, 61% and 75% (dec. and con., respectively) of the variation in the measured time series was explained by the model. These results are important for moving towards operational remote sensing of forest carbon balance across Northern Europe.

Long-term vegetation changes in the northern Scandinavian forest limit: a human impact-climate synergy?

A palaeoecological study was performed in the northern Scandinavian mountain range in Sweden. The aim was to study vegetation changes and shifts in forest limit altitudes during the last 5000 years in a tree-less archaeological site (Adamvalta) situated below the regional forest limit, and in a forested reference area with similar geological features but without archaeological evidence of human presence (Ajdevaratj). The suitability of uncritically using forest limit changes as indicators of climate change is also discussed. The study included analyses of pollen, pollen accumulation rates (PAR), macrofossils and loss-on-ignition. The results indicate vegetation changes in both areas plausibly caused by climate c. 3800 BP and c. 500 400 BP. However, at Adamvalta, settlements were established c. 1300 750 BP, close to the mountain birch ( Betula pubescens ssp. czerepanovi) forest limit. About 800 BP, the birch forest cover at Adamvalta decreased and the vegetation developed into an alpine heath, as a result of human-induced deforestation. The following ‘Little Ice Age’, in combination with human impact from the sixteenth century onwards, prevented forest recovery, and the site remains treeless. Such vegetation changes were not recorded at Adjevaratj. It is deduced that the present position of the forest limit at Adamvalta is governed by a combination of factors where previous human impact and climate have been the major driving forces determining the long-term vegetation development. Hence, a thorough knowledge of the site history is important when forest limits are used as a proxy for climate change.

Estimating net primary production for Scandinavian forests using data from Terra/MODIS

A model for estimating net primary production (NPP) across Scandinavia has benn developed. The model is based on the light-use efficiency (LUE) concept, where NPP is calculated as a product of the amount of absorbed photosynthetically active radiation (APAR) and a LUE-factor ( ε) controlling the efficiency by which vegetation transforms photosynthetically active radiation (PAR) into biomass. The fractional APAR (FAPAR) is obtained by a linear transformation of 250 m normalized difference vegetation index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS). Prior to the transformation, the NDVI time series were seasonally adjusted by fitting local asymmetric Gaussian curves to the data thereby minimizing cloud contamination and other noise factors such as BRDF-related variation. The APAR is then calculated as a product of FAPAR and incident PAR, where the latter is obtained from the “Swedish Regional Climate Modelling Programme” (SWECLIM). The LUE-factor is modeled as a daily function of temperature, latitude, and day of the year (DOY). The FAPAR dataset was validated against measurements of fractional intercepted PAR (FIPAR) that were carried out at Norunda experimental site in central Sweden (60°5′N, 17°29′E) between August and October, 2001. The calculated FAPAR time series are in good agreement with the measurements. The modeled NPP is evaluated against flux measurements carried out in Norunda 1997–1999. The determination coefficients obtained when comparing modeled with measured data are R 2 = 0.82 for 2000 (RMSE = 2.71 g C m −2 d −1), and R 2 = 0.68 for 2001 (RMSE = 3.57 g C m −2 d −1) (time series averaged every 10th day).

Heterobasidion annosum root rot in Picea abies: Modelling economic outcomes of stump treatment in Scandinavian coniferous forests

The economic outcomes of stump treatment against spore infections of the root rot pathogen Heterobasiodion annosum s. l. were analysed based on simulations in four stands typical of Swedish forestry and forest management: (A) Norway spruce [Picea abies (L.) Karst.] stand on former agricultural soil (SI = 32), (B) Norway spruce stand (SI = 26) on forest land; (C) Mixed stand of Norway spruce and Scots pine (Pinus sylvestris L.) (SI = 24) with only H. parviporum present, i.e. no infection of Scots pine and no possibility of interspecies spread of disease between hosts; and (D) same as C, but H. annosum s. str. (Fr.) Bref and H. parviporum Niemelä & Korhonen present, i.e. interspecies spread of disease possible. Models for disease development, growth and yield and cross-cutting were used in the simulations. The simulated decay frequency in Norway spruce trees ranged between 2 and 90%. Stump treatment at the previous final felling and in all thinning operations was profitable at interest rates 1 and 3% in stands A, B and D, but not in stand C. In stand C, no stump treatment at all or treatment in thinnings only gave the highest net future value. Implications for stump treatment in practical forestry are discussed.

Identification of two genera of N2-fixing cyanobacteria growing on three feather moss species in boreal forests of Quebec, Canada

The recent discovery that N2fixation rates by the feather moss carpet of boreal Scandinavian forests increases with stand maturity has put into question the paradigm that N2fixation is negligible in mature boreal forest. The N2fixation was attributed to a previously unknown association between Nostoc sp., a N2-fixing cyanobacteium and Pleurozium schreberi (Brid.) Mitt., a feather moss that is abundant worldwide in the boreal forest. Here we report for the first time that this association also exists in the Canadian boreal forest. We discovered, however, that Nostoc was found growing not only on Pleurozium but also on two other moss species ( Hylocomnium splendens (Hedw.) Br. Eur. and Ptillium crista-castrensis (Hedw.) De Not.). In addition, the N2-fixing cyanobacterium Stigonema sp. was observed on the three moss species mentioned above, indicating the existence of six different associations. At least one of the six associations was found at 9 of 13 sites that are representative of a large area of the Quebec boreal forest. These findings suggest possibilities for further research, aimed at measuring the unaccounted for N2-fixing potential of the feather moss carpet in Canadian boreal forests.

IN MEMORIAM: GUNNAR SVÄRDSON, 1914–2004

Gunnar Svardson, Professor Emeritus at the Freshwater Laboratory, Drottningholm, Sweden, and Corresponding Fellow of the AOU, was born on 19 September 1914 in Stockholm. He celebrated his 90th birthday shortly before his unexpected death in Stockholm on 6 November 2004. He was one of Sweden's best known and most highly respected evolutionary biologists and ornithologists. His strong interest in natural history emerged early. After finishing school, he studied zoology, botany, and geography at the University of Stockholm. Like many biologists, he started out primarily as bird watcher and had lifelong passion for ornithology. Yet his best-known scientific contributions were based on studies of freshwater fish. In 1945 he presented his doctoral thesis, titled simply Chromosome Studies on Salmonidae. In his thesis, which is still cited, focused on a of whitefish (Coregonus) in Scandinavian freshwaters and demonstrated that it actually consisted of up to half dozen genetically incompletely isolated populations, each adapted to certain set of environmental circumstances. The introgression of genes into each of them from one or more of the others prevented their definite fission and kept them in state of lasting incipiency. Svardson's work led to an entirely novel appreciation of the evolutionary history, genetics, and systematics of the genus Coregonus, and to day it provides one of the most fascinating and intriguing examples of the dynamics of speciation in population groups. applied an impressive array of methods and concepts, including cytology, biogeography, and behavior. A similar approach was later used by him to study other groups of salmonids and by other researchers for great variety of other animal taxa. Moreover, in today's world of biotic globalization and violent anthropogenic perturbations of animal and plant communities, Svardson's insights into the processes of species formation and splitting have received increased attention. Hybridization is widely regarded as one of the theoretically and practically most important phenomena in population genetics, as well as in the struggle to preserve the world's biodiversity. As the ideas of the Modern Synthesis reached Scandinavia during and after the war, was one of the few who quickly realized the fundamental significance of new way of thinking and became its leading proponent and defender in Sweden. Breaking as they did with the Linnaean tradition of systematics in Sweden, the new ideas aroused acrimonious feelings in wide and influential circles, and was involved in many heated arguments. It is truly refreshing to read his crystal-clear contributions to debate, and more than almost anything he published, those texts show him decades ahead of his time. Very little would have to be changed to make these publications reflect today's state of the art in evolutionary biology. Another major contribution flowed from Svardson's detailed familiarity with birds and bird communities in Scandinavian forests. In comparatively brief paper in Oikos (1949), he presented an innovative model of the different evolutionary and ecological consequences of intraspecific and interspecific competition. Although based on bird work, the general applicability of the model was quickly realized in many quarters, and more than one of the most prominent (if aging) ecologists of the late 20th century have in conversations mentioned to me that Svardson 1949 was major eyeopener for them and greatly influenced their own research in community once related to me that particular paper had been summarily rejected by the editor-inchief of the new journal, with the argument that this is not ecology. In those days, long before MacArthur, the attitude in Scandinavia was that

Influence of a deer carcass on Coleopteran diversity in a Scandinavian boreal forest: a preliminary study

We tested the effect of a large ungulate carcass on boreal forest biodiversity by contrasting the local abundance and diversity of Coleoptera around a roe deer Capreolus capreolus carcass and in a control plot, between 8 August and 3 September 2003, in southern Norway. The two plots differed both in occurrence and richness of species, which were almost double at the carcass plot, although the diversity indices were similar. The higher evenness of the control plot compensated for its lower number of species, probably because the carcass plot was a disturbed area, colonized by many species, which were represented by few individuals. The number of beetles captured each day correlated positively with temperature at the control plot, but not at the carcass plot, indicating that the presence of an abundant and concentrated resource increased the local activity of Coleoptera. The carcass is likely to create a particular microclimate, which could partly buffer against extremes of air-temperature variation. These preliminary results indicate that ungulate carcasses have a significant ecological impact, which should be further investigated to improve the management and restoration of European boreal forest ecosystems.

The saproxylic beetleBolitophagus reticulatus: its frequency in managed forests, attraction to volatiles and flight period

Reduction in amount of dead trees in Scandinavian forests due to intensive forest management has aroused interest in the requirements of saproxylic (wood‐living) species. Much attention has been focused onBolitophagus reticulatus, a tenebrionid beetle that lives on polypore fruiting bodies ofFomes fomentarius. Although earlier studies have suggested that the species has limited dispersal abilities, the beetle is abundant and widely distributed in Swedish forests. To resolve this paradox we conducted a series of field experiments. Firstly, the frequency of the species was found to be similar in six forest stands with a low density of fruiting bodies and six stands with a high density. Secondly, flying individuals were caught in window traps placed in all of eight randomly chosen, well‐managed pine stands. Thirdly, we tested volatiles that flying beetles may use to find hosts by baiting window traps. We found strong attractions to ethanol and to a combination of ethanol and fruiting body. The dispersal period was almost entirely restricted to one week during the summer. Our results suggest thatB. reticulatusis distributed wherever the host occurs. Long distance dispersal ofB. reticulatusis difficult to observe, but appears to be effective when it does occur. Previously observed patchy distribution patterns of the species are probably due to short‐distance movements being more frequent than long‐distance movements. A general conclusion is that interpretations based on mark‐recapture data and indirect measures of substrate and beetle occurrences that claims limited dispersal should be treated with caution.

Ecological continuity and assumed indicator fungi in boreal forest: the importance of the landscape matrix

In a boreal forest in southeast Norway, we evaluated the relative importance of stand-level structures versus historical data on forest age and absence of logging (at two spatial scales; stand and surrounding landscape), on the presence and abundance of the wood-rotting fungi Phellinus nigrolimitatus and Cystostereum murraii. Both species are often considered to be indicators of long-time continuous presence of downed logs in Scandinavian forest stands. Of the stand-level variables, number of logs in late stages of decay was positively related to P. nigrolimitatus presence, while diversity of coarse woody debris was positively related to the abundance of the species. Both the presence and abundance of P. nigrolimitatus was strongly and positively correlated with the area of forest uninterrupted by major disturbance the past 240 years (equalling 140 years of “old growth continuity”) in the surrounding landscape (80 ha). For C. murraii, consistent results was not found. We conclude that the causal relationships between ecological continuity and possible indicator species must be investigated on a larger scale than the stand-level as the condition of the forest surrounding a stand can have a large influence on these relationships.

Editorial - Value of nature conservation: the good or the context?

Editorial - Value of nature conservation: the good or the context?