Boreal Taiga Research Articles

From oligotrophy to dystrophy: the ontogeny of a humic lake in an extrazonal boreal taiga in Central Europe

ABSTRACTWhile humic lakes are common in northern Europe, in central Europe they are rare and our understanding of their ontogeny is insufficient. Here, we present the reconstruction of the development of a humic lake in the Tatra Mountains (Slovakia) over the last 8000 years using chironomids along with diatoms, pollen and non‐pollen palynomorphs. The compositional changes in aquatic proxies suggest three developmental stages. Since its formation the lake has been oligotrophic (phase 1), and its chemistry was controlled by subsurface waters rich in base cations buffering the effect of acid humic substances from forest and peat that were already present in the catchment. The beginning of the transition to phase 2 (~4400 cal a bp) is marked by simultaneous alterations in all proxies. Climate change combined with the local geochemistry was able to alter the limnological conditions supporting unique chironomid assemblages that have no analogues in recent Carpathian lakes. At ~3400 cal a bp the lake shifted to a phase when acidophilic/acidotolerant taxa indicate characteristic humic lake conditions (phase 3). Some chironomid taxa appearing ~2000 years ago for the first time indicate a dystrophic state in which the lake has remained until now. Human activities have been detected in the area since the Aeneolithic but had no direct influence on the lake.

The Distribution Characteristics of Vegetation in the Subrange of the Altai Mountains, Xinjiang.

The Altai Mountains are an important center of biodiversity and are a major habitat for threatened and endemic species in Asia. Moreover, the Altai Mountains are a valuable site for the study of the evolution of central Asian vegetation. The Xinjiang Altai subrange represents the largest part of the southern Altai Mountains and has many unique plant communities. After conducting a thorough literature review and field investigation, we utilized the Chinese vegetation categorization system to identify the dominant plant communities in the Xinjiang Altai subrange and report their composition and distribution characteristics. Our results show that (1) the natural plant communities present in the Xinjiang Altai subrange can be divided into eight vegetation types, eighteen vegetation subtypes, and 50 communities. Among these, two communities-Form. Calligonum rubicundum and Form. Seriphidium borotalense-Festuca valesiaca-are present only in the Xinjiang Altai subrange. (2) The Xinjiang Altai subrange is located at the junction of three major biomes containing unique vegetation types (coniferous forest, temperate broadleaf forest, and desert). Thus, the Xinjiang Altai subrange is distinct in its staggered transition from mountainous boreal taiga to temperate desert. This research provides textual data to contextualize the cultural heritage of the Xinjiang Altai subrange and also provides a scientific basis for the protection and sustainable management of natural resources found in the Xinjiang Altai.

Detecting the Archaeological Traces of Tar Production Kilns in the Northern Boreal Forests Based on Airborne Laser Scanning and Deep Learning

This paper presents the development and application of a deep learning-based approach for semi-automated detection of tar production kilns using new Finnish high-density Airborne Laser Scanning (ALS) data in the boreal taiga forest zone. The historical significance of tar production, an important livelihood for centuries, has had extensive environmental and ecological impacts, particularly in the thinly inhabited northern and eastern parts of Finland. Despite being one of the most widespread archaeological features in the country, tar kilns have received relatively little attention until recently. The authors employed a Convolutional Neural Networks (CNN) U-Net-based algorithm to detect these features from the ALS data, which proved to be more accurate, faster, and capable of covering systematically larger spatial areas than human actors. It also produces more consistent, replicable, and ethically sustainable results. This semi-automated approach enabled the efficient location of a vast number of previously unknown archaeological features, significantly increasing the number of tar kilns in each study area compared to the previous situation. This has implications also for the cultural resource management in Finland. The authors’ findings have influenced the preparation of the renewal of the Finnish Antiquities Act, raising concerns about the perceived impacts on cultural heritage management and land use sectors due to the projected tenfold increase in archaeological site detection using deep learning algorithms. The use of environmental remote sensing data may provide a means of examining the long-term cultural and ecological impacts of tar production in greater detail. Our pilot studies suggest that artificial intelligence and deep learning techniques have the potential to revolutionize archaeological research and cultural resource management in Finland, offering promising avenues for future exploration.

Distribution and Structure Analysis of Mountain Permafrost Landscape in Orulgan Ridge (Northeast Siberia) Using Google Earth Engine

An analysis of the landscape spatial structure and diversity in the mountain ranges of Northeast Siberia is essential to assess how tundra and boreal landscapes may respond to climate change and anthropogenic impacts in the vast mountainous permafrost of the Arctic regions. In addition, a precise landscape map is required for knowledge-based territorial planning and management. In this article, we aimed to explore and enhanced methods to analyse and map the permafrost landscape in Orulgan Ridge. The Google Earth Engine cloud platform was used to generate vegetation cover maps based on multi-fusion classification of Sentinel 2 MSI and Landsat 8 OLI time series data. Phenological features based on the monthly median values of time series Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), and Normalized Difference Moisture Index (NDMI) were used to recognize geobotanical units according to the hierarchical concept of permafrost landscapes by the Support Vector Machine (SVM) classifier. In addition, geomorphological variables of megarelief (mountains and river valleys) were identified using the GIS-based terrain analysis and landform classification of the ASTER GDEM scenes mosaic. The resulting environmental variables made it possible to categorize nine classes of mountain permafrost landscapes. The result obtained was compared with previous permafrost landscape maps, which revealed a significant difference in distribution and spatial structure of intrazonal valleys and mountain tundra landscapes. Analysis of the landscape structure revealed a significant distribution of classes of mountain Larix-sparse forests and tundra. Landscape diversity was described by six longitudinal and latitudinal landscape hypsometric profiles. River valleys allow boreal–taiga landscapes to move up to high-mountainous regions. The features of the landscape structure and diversity of the ridge are noted, which, along with the specific spatial organization of vegetation and relief, can be of key importance for environmental monitoring and the study of regional variability of climatic changes.

Alien and aboriginal flora of the Amur section of the Trans-Siberian Railway and its relationships with the characteristics of natural biomes

An inventory of alien and native species of vascular plants was taken along the Trans-Siberian Railway, from the settlement of Yerofey Pavlovich to Kundur-Khabarovskiy railway station, with the total length of 1043 km (11 % of the TSR) explored. The study encompassed sixteen railway stations located in two biomes, including Amur-Zeya Boreal Taiga with variants southern taiga and subtaiga, and Zeya-Bureya Nemoral Broadleaved Forests and Forest-Steppe ones. The highest similarity was displayed by south taiga and subtaiga variants of the Amur-Zeya Boreal Taiga biome, with Sørensen’s coefficient equaling to Ks = 46 % on embankment slopes and Ks = 45 % for rail bed, while a low measure of similarity was detected in the railway right of way (Ks = 24 %). The number of railway flora species displays a strong positive correlation with average annual temperature and average annual precipitation within the biome, and a strong negative correlation with the total number of vascular plants recorded within the biome, as well as with the biome area.

Elemental and Molecular Composition of Humic Acids Isolated from Soils of Tallgrass Temperate Rainforests (Chernevaya taiga) by 1H-13C HECTCOR NMR Spectroscopy

The soils of Chernevaya taiga (tallgrass fir-aspen hemiboreal rainforest) have high fertility in comparison with oligotrophic analogs formed in boreal taiga. We have studied humic acids isolated from the soils of Chernevaya and oligotrophic taiga in the Novosibirsk, Tomsk, Kemerovo and the Altai regions of Russia and for the first time the structural and molecular composition of humic acids was determined using 13C CP/MAS and 1H-13C HETCOR NMR spectroscopy. According to data obtained in this study, up to 48% of aromatic compounds accumulate in the soils of Chernevaya taiga, which is higher than in the oligotrophic taiga and comparable with this rate of steppe Chernozems. In the course of active processes of transformation of organic matter, a significant number of aromatic fragments accumulates in the middle horizons of soil profiles. Using 13C CP/MAS spectroscopy, it was possible to identify the main structural fragments (aliphatic and aromatic) that formed in humic acids of the Chernevaya taiga. The HETCOR experiment made it possible to accurately determine the boundaries of chemical shifts of the main groups of structural fragments of humic acids. Our results demonstrate that the stabilization of organic compounds occurs in the soil of the Chernevaya taiga, which leads to the resistance of organic matter to biodegradation that is not typical for benchmark soils of boreal environments.

First identification of Parnassius apollo and P. nomion (Lepidoptera: Papilionidae) larval host plants in Mongolia

We initiated a project to study the ecology of P. apollo and the more common congener P. nomion, which is sympatric in Mongolia. One of our primary goals was to gather data on P. apollo and P. nomion butterfly habitat associations, including especially larval host plant species. We conducted our work in the boreal taiga forests of the Khentey Mountain Range in the southern Siberian ecological region of Mongolia. We systematically searched for suitable habitat for larvae and once we located caterpillars, we identified the host plants and gathered data on habitat associations. We found both P. apollo and P. nomion caterpillars on host plants at several sites and evidence of eclosed pupae at a couple of sites, enabling us to identify the host plants, a crucial piece of information needed to develop conservation programming and habitat modeling. The host plant species were the stonecrops Sedum aizoon, Sedum telephium (syn. Sedum purpureum), and Rhodiola rosea (syn. Sedum rosea). We further describe the habitat associations in which we found the caterpillars. For these butterfly species, the exact host plants in Mongolia remained unknown until we conducted this work.

Doubling of biomass production in European boreal forest trees by a four-year suppression of background insect herbivory

Background insect herbivory, i.e. the minor but chronic plant damage caused by insects, is usually considered ‘negligible’ for plants when compared with the severe defoliation associated with forest pest outbreaks. We experimentally tested the hypothesis that the impacts of background herbivory on tree growth and mortality accumulate over years, resulting in much larger effects than usually assumed. In boreal taiga forests near Arkhangelsk (Northern Russia), application of insecticide at 10-day intervals for four growth seasons (June–September of 2014–2017) decreased foliage losses to insects in our study species (early successional deciduous Betula pubescens and Populus tremula; late successional coniferous Picea abies and Pinus sylvestris) from 2.04–6.35% to 0.72–1.18%. The magnitude of the insecticide treatment effect on plant losses to defoliating insects varied considerably among the study species, with the highest effect observed in white birch and the lowest effects in the two late successional species. Across all tree species, insecticide treatment nearly doubled the increase in tree biomass relative to control plots, demonstrating that background insect herbivory has major negative impacts on tree growth and productivity. The insecticide-treated plots showed the largest increase in biomass in Norway spruce and the smallest increase in European aspen when compared to the control plots. The changes in birch growth following the release from insect herbivory were three times greater than the effects of the same level of simulated herbivory in an earlier experiment, thereby hinting at the importance of herbivore-specific elicitors in the growth suppression of trees damaged by insects. The mortality of late successional species in the treatment plots increased nearly three-fold, whereas the mortality of early successional species did not change relative to controls, suggesting an increase in competitiveness of the early successional trees released from herbivory. Thus, in agreement with an earlier modelling study, we conclude that minor herbivore damage, over the long term, substantially reduces biomass production in North European forest trees. Due to differential effects on coexisting tree species, this damage has a pronounced impact on plant competitiveness and affects both the productivity and the structure of boreal forests.

Identifying novel treeline biomarkers in lake sediments using an untargeted screening approach

Paleolimnology uses sedimentary biomarkers as proxies to reconstruct long-term changes in environmental conditions from lake sediment cores. This work describes an untargeted metabolomics-based approach and uniquely applies it to the field of paleolimnology to identify novel sediment biomarkers to track long-term patterns in treeline dynamics. We identified new potential biomarkers across the Canadian northern Arctic, non-alpine, treeline using high-resolution accurate mass spectrometry, and pattern recognition analysis. This method was applied to 120 sediment core extracts from 14 boreal, 25 forest-tundra, and 21 tundra lakes to assess long-term fluctuations in treeline position. High resolution accurate mass spectrometry resolved many compounds from complex mixtures with low mass accuracy errors. This generated a large dataset that required metabolomics styled statistical analyses to identify potential biomarkers. In total, 29 potential biomarkers discriminated between boreal and tundra lakes. Tetrapyrrole-type phorbides and squalene derivatives dominated in boreal regions, while biohopane-type lipids were in the tundra regions. Tetrapyrroles were in both surface and subsurface sediments of boreal lakes indicating these compounds can survive long-term burial in sediments. At the ecozone level, tetrapyrroles were more abundant in boreal Taiga Shield, and Taiga Plains. Boreal plant extracts belonging to Pinaceae and Ericaceae also contained tetrapyrroles. Squalene derivatives demonstrated long-term preservation, but wider distribution than tetrapyrroles. Hopanoids were present in tundra and forest-tundra lake regions, specifically the Low Arctic and Taiga Shield, and were absent in all boreal lake sediments. Herein, we describe a method that can systematically identify new paleolimnological biomarkers. Novel biomarkers would facilitate multi-proxy paleolimnological studies and potentially lead to more accurate paleoenvironmental reconstructions.

Upper Paleolithic site Tuyana – a multi-proxy record of sedimentation and environmental history during the Late Pleistocene and Holocene in the Tunka rift valley, Baikal region

The complex study of the 3.5-m thick section of the multi-genetic sediments of the Late Paleolithic Tuyana site (Tunka rift valley, Baikal region) resulted in a first detailed record of the change in environment and climate of the ancient humans’ habitation in the Tunka rift valley in Late Pleistocene and Holocene in the interval of >36 ka cal BP until Late Holocene. Sedimentation processes in the section are characterized by multiple remobilizations. Redeposition traces are most strongly expressed in МIS 3 sediments. Apparently, an intensive transient removal of slope sediments took place here at МIS 2. The common tendency of the natural environment and habitation conditions of the ancient humans in the Tunka valley show domination of the open and relatively dry tundra-steppe with areas of forests vegetation in the end of MIS 3, mostly dry steppes with limited forest-tundra and tundra associations in MIS 2 with the spread of boreal taiga in Holocene. Tunka rift valley around 50 ka cal BP had already been settled by humans and was visited by them during the periods of relatively favorable climatic conditions: during the MIS 3 optimums and in Middle Holocene. The Tuyana Paleolithic complexes have extensive analogies with the Aurignacian industries of Eurasia. The closest similarities could be drawn with the complexes of Kulbulakien culture in Middle Asia and Kazakhstan. The Tuyana site is currently the most eastern occurrence of the Aurignacian culture in Eurasia.

Changes in diatom and chironomid assemblages of boreal taiga in East Siberia (58N, Lake Aunakit, Russia) during the last 4.2 ka

The author has studied phenetic and taxonomic relationships of the Baikal endemic sculpins of the genus Cottocomephorus Pellegrin 1900. For this purpose, the author has performed a morphometric investigation by five meristic and 29 plastic characters, as well as analysed the characteristics of colouring and the number of preopercular spines. The author has confirmed the validity of three species: C. grewingkii (Dybowski, 1874), C. inermis (Yakowlev, 1890) and C. comephoroides (Berg, 1901). The differentiation of the studied species is based on the number of gill rakers and preopercular spines, the width of the interorbital distance, height and width of the head, the length of the pectoral fins and the characteristics of the in-life colouration. Based on the revision of the diagnostic features, the author has suggested a new key to identify species.

Changes of Soil C Stock under Establishment and Abandonment of Arable Lands in Permafrost Area—Central Yakutia

Central Yakutia is in one of the most northern agricultural centers of the world. In this territory a notable area of arable land was made by removing the boreal Taiga with the primary purpose of crop cultivation. Such a method of cultivation significantly changes soil total carbon (STC, soil organic carbon + soil carbonate carbon) balance, because of the destroyed upper humus horizon. Soil organic carbon (SOC) of cultivated arable lands is almost a half of that in forest. In abandoned arable lands with grass vegetation, the recovery of SOC has increased to 30% in comparison with cultivated arable lands. On arable lands recovering with new growth of trees, the SOC is related to the abandonment period. Soil carbonates carbon (SCC) content was significantly lower than SOC and showed significant difference among abandoned and other types of arable lands. Objectives of this study are to identify how STC stocks change in response to conversion of the forests to agricultural land and to analyze the arable land system’s recovery process after abandonment. Furthermore, after transformation of forest to arable land, a significant decrease of STC was observed, primarily due to mechanical loss after plant residue removal. It was also identified that the restoration and self-recovery of STC in abandoned arable lands of Central Yakutia continuously and slightly increase. Grass vegetation regenerates STC for 20 years. While the difference of average STC of forests and cultivated arable lands reached 41%, a new growth of forest on some abandoned arable land follows the tendency of STC decrease due to a low productivity level and suppressing effect on grass vegetation.

Insight into the Last Glacial Maximum climate and environments of the Baikal region

This study presents a multi‐proxy record from Lake Kotokel in the Baikal region at decadal‐to‐multidecadal resolution and provides a reconstruction of terrestrial and aquatic environments in the area during a 2000‐year interval of globally harsh climate often referred to as the Last Glacial Maximum (LGM). The studied lake is situated near the eastern shoreline of Lake Baikal, in a climatically sensitive zone that hosts boreal taiga and cold deciduous forests, cold steppe associations typical for northern Mongolia, and mountain tundra vegetation. The results provide a detailed picture of the period in focus, indicating (i) a driest phase (c. 24.0–23.4 cal. ka BP) with low precipitation, high summer evaporation, and low lake levels, (ii) a transitional interval of unstable conditions (c. 23.4–22.6 cal. ka BP), and (iii) a phase (c. 22.6–22.0 cal. ka BP) of relatively high precipitation (and moisture availability) and relatively high lake levels. One hotly debated issue in late Quaternary research is regional summer thermal conditions during the LGM. Our chironomid‐based reconstruction suggests at least 3.5 °C higher than present summer temperatures between c. 22.6 and 22.0 cal. ka BP, which are well in line with warmer and wetter conditions in the North Atlantic region inferred from Greenland ice‐cores. Overall, it appears that environments in central Eurasia during the LGM were affected by much colder than present winter temperatures and higher than present summer temperatures, although the effects of temperature oscillations were strongly influenced by changes in humidity.

Post-fire carbon and nitrogen accumulation and succession in Central Siberia

Improved understanding of carbon (C) accumulation after a boreal fire enables more accurate quantification of the C implications caused by potential fire regime shifts. We coupled results from a fire history study with biomass and soil sampling in a remote and little-studied region that represents a vast area of boreal taiga. We used an inventory approach based on predefined plot locations, thus avoiding problems potentially causing bias related to the standard chronosequence approach. The disadvantage of our inventory approach is that more plots are needed to expose trends. Because of this we could not expose clear trends, despite laborious sampling. We found some support for increasing C and nitrogen (N) stored in living trees and dead wood with increasing time since the previous fire or time since the previous stand-replacing fire. Surprisingly, we did not gain support for the well-established paradigm on successional patterns, beginning with angiosperms and leading, if fires are absent, to dominance of Picea. Despite the lack of clear trends in our data, we encourage fire historians and ecosystem scientists to join forces and use even larger data sets to study C accumulation since fire in the complex Eurasian boreal landscapes.

How much carbon can the Siberian boreal taiga store: a case study of partitioning among the above-ground and soil pools

In the context of global carbon cycle management, accurate knowledge of carbon content in forests is a relevant issue in contemporary forest ecology. We measured the above-ground and soil carbon pools in the dark-coniferous boreal taiga. We compared measured carbon pools to those calculated from the forest inventory records containing volume stock and species composition data. The inventory data heavily underestimated the pools in the study area (Stolby State Nature Reserve, central Krasnoyarsk Territory, Russian Federation). The carbon pool estimated from the forest inventory data varied from 25 (t ha−1) (low-density stands) to 73 (t ha−1) (highly stocked stands). Our estimates ranged from 59 (t ha−1) (low-density stands) to 147 (t ha−1) (highly stocked stands). Our values included living trees, standing deadwood, living cover, brushwood and litter. We found that the proportion of biomass carbon (living trees): soil carbon varied from 99:1 to 8:2 for fully stocked and low-density forest stands, respectively. This contradicts the common understanding that the biomass in the boreal forests represents only 16–20 % of the total carbon pool, with the balance being the soil carbon pool.

Population trends in boreal birds: Continuing declines in agricultural, northern, and long-distance migrant species

When many environmental changes take place simultaneously, one of the first challenges for conservation efforts is to identify the species and environments that are in the most need of conservation measures. We studied whether there are differences in the population growth trends of 94 boreal bird species according to their migration strategies, breeding distributions (northern or southern), or breeding habitats. To this end, we examined recent trends in bird census data covering >1000km along a north–south transect in Finland, from the deciduous forests on the southern coast through the boreal taiga forest to the alpine fell area in the north. Our results show that long-distance migrants (species wintering in western or eastern Africa or Asia), northern species, and species living in agricultural environments are in decline in north-eastern Europe. The results were the same for both the long-term (27years; 1986–2012) and the short-term (12years, the most recent reporting period of the EU bird directive; 2001–2012) data set. Additionally, species breeding mainly in urban/sub-urban environments, coniferous forests, or wetlands showed negative growth trends, especially over the short-term. These results provide updated information that can be used to determine the targets of conservation efforts focused on Northern Palaearctic birds. Several different conservation measures may be needed to help these populations, ranging from protecting habitat in the migration and wintering grounds to changing climate and agricultural policies at a national and/or international level. In addition, further research is needed to identify the particular mechanisms underlying the population trends.

Private and public information use strategies by foraging groups of wild Siberian jays

In variable environments variance-sensitive foraging should be replaced by more profitable sampling behaviour whenever the variation in foraging rewards becomes predictable enough to track. We tested this suggestion in groups of wild Siberian jays, Perisoreus infaustus, during prewinter food-hoarding visits to experimental feeders. As predicted, all groups of jays switched to sampling once food items were clumped into ‘patches’ to create reliable patch-based information concerning prey sizes. However, increases in individual foraging success above chance were not achieved according to a simple ‘win-stay lose-shift’ rule of thumb. Instead jays employed a win-and-return-later strategy, returning more often over the experimental session to privately sampled patches containing the four largest of five prey sizes. In contrast, public information that was gained by observing patch sampling by other group members involved a more gradual increase in the probability of patch use with the prey size involved. Use of public versus private information did not differ according to sex or social status. Even though the jays did not achieve the individually optimal strategy in this specific experimental set-up, their sampling behaviour using both public and private information are suggested to maximize both individual and group-wide foraging efficiencies when exploiting the ephemeral food sources typical of boreal taiga forests.

Bioclimate-Vegetation Interrelations along the Pacific Rim of North America

This study was designed to examine relationships between climate and vegetation of the Pacific rim of North America, from the Mediterranean deserts of California to Alaska’s boreal taiga. Relations were inferred from temperature and rainfall data recorded at 457 weather stations and by sampling the vegetation around these stations. Climate data were used to construct climatograms, calculate forty one variables and detect main latitudinal and longitudinal gradients. In order to identify the best functions able to relate our variables, polynomial and non-polynomial regressions were performed. The k-means algorithm was the clustering method used to validate the variables that could best support our bioclimatic classification. The variable that best fitted our classification was finally used to prepare a discriminatory key for bioclimates. Across this extensive area three macrobioclimates were identified, Mediterranean, Temperate and Bo- real, within which we were able to distinguish nine bioclimates. Finally, we relate the different types of potential natural vegetation to each of these bioclimates and describe their floristic composition and physiognomy.

Differences in the forest landscape structure along the Finnish–Russian border in southern Karelia

This study describes forest landscape fragmentation and connectivity along the Finnish–Russian border near the Karelian Isthmus. The landscape pattern was analysed using classification data based on Landsat ETM+ and Landsat TM images in combination with systematic surveys in Finland (Finnish National Forest Inventory) (n=546) and the authors’ own fieldwork data in Russia (n=101). On the Finnish side the forest patches are significantly smaller than on the Russian side. In addition, the Finnish forests landscape is more scattered and distances between patches of the same forest type are longer. The Russian side is more dominated by broadleaved and mixed forest stands. The disparities are due to differences in forestry policy and traditions of forest practices. The growing conditions of the areas are similar. The habitat fragmentation and habitat connectivity are important issues because the Karelian Isthmus is one of three main corridors and migrating routes connecting large Russian boreal taiga forests and their fauna and flora with Finnish isolated boreal forests.

Inference of hazel grouse population structure using multilocus data: a landscape genetic approach

In conservation and management of species it is important to make inferences about gene flow, dispersal and population structure. In this study, we used 613 georeferenced tissue samples from hazel grouse (Bonasa bonasia) where each individual was genotyped at 12 microsatellite loci to make inference on population genetic structure, gene flow and dispersal in northern Sweden. Observed levels of genetic diversity suggest that Swedish hazel grouse do not suffer loss of genetic diversity compared with other grouse species. We found significant F(IS) (deviation from Hardy-Weinberg expectations) over the entire sample using jack-knifed estimators over loci, which is most likely explained by a Wahlund effect. With the use of spatial autocorrelation methods, we detected significant isolation by distance among individuals. Neighbourhood size was estimated in the order of 62-158 individuals corresponding to a dispersal distance of 950-1500 m. Using a spatial statistical model for landscape genetics to infer the number of populations and the spatial location of genetic discontinuities between these populations we found indications that Swedish hazel grouse are divided into a northern and a southern population. We could not find a sharp border between these two populations and none of the observed borders appeared to coincide with any potential geographical barriers.These results imply that gene flow appears somewhat unrestricted in the boreal taiga forests of northern Sweden and that the two populations of hazel grouse in Sweden may be explained by the post-glacial reinvasion history of the Scandinavian Peninsula.