This study aims to investigate and disentangle the impact of land use and climate variability on the Baltic Sea coastal zone from a millennial perspective. To assess the environmental status of the coastal zone we make use of siliceous microfossils (mainly diatoms), stable nitrogen and carbon isotopes, organic carbon accumulation rates, and lithological changes analyzed in a sediment core collected in Gamlebyviken, Swedish east coast, dated to cover the last 3000 years. Changes in land use and vegetation cover are modelled using pollen stratigraphical data to obtain the percentage coverage of coniferous woodland (Pinus and Picea), deciduous woodland, wetland (Cyperaceae), grassland (including Juniperus) and cropland (cereals) while changes in climatic conditions are assessed through well-documented climatic periods that have occurred in the Baltic Sea region. The reconstructed regional vegetation cover shows that already 3000 years ago, humans used the landscape for both animal husbandry (grasslands) and farming (cropland), but the impact on the Baltic coastal waters was minor. The diatom accumulation rates were quite high (∼3100–2600 cal yr BP) containing taxa indicative of high nutrient conditions/upwelling, and stable carbon isotopes show that the carbon was produced in the basin but did not result in elevated organic carbon accumulation rates. A gradual change to less marine conditions in Gamlebyviken from about 2500 to 1400 cal yr BP can be attributed to the ongoing land uplift which resulted in a more enclosed embayment with only a narrow inlet area today. The Medieval Climate Anomaly (1000–700 cal yr BP/950–1250 CE) is a time where extensive eutrophication is registered in the open Baltic Sea, but afforestation is recorded between 1000 and 500 cal yr BP and attributed to the expansion of spruce favored by land-use reorganization with a transition from a one-course rotation system to the three-course rotation system fully established in southern Sweden in the 13th century, and only minor environmental change is recorded in the coastal zone. The Little Ice Age is documented in our data between 400 and 250 cal yr BP/1550–1700 CE as a decrease in regional cropland (cereals) cover, possibly indicating years of poor crop harvest, and changes in the Baltic coastal zone are evidenced as low carbon and diatom accumulation rates, increase in benthic diatom taxa (low turbidity), and high abundance in diatom taxa associated with sea ice indicating a cold climate. The most significant changes occurred from about 100 cal yr BP/1850 CE up to present, with a maximum regional cover of grassland and cropland (ca. 35%) at the expense of deciduous woodland, and major changes indicative of a highly eutrophic environment recorded in the coastal zone. Organic carbon accumulation rates peaked in 1968 CE at approximately 134 g C m2 yr−1 before subsequently declining to present-day values of 53 g C m2 yr−1, mirroring a similar trend observed in diatom accumulation rates. The high organic carbon accumulation rate shows that deep unvegetated accumulation bottoms in the coastal Baltic Sea serve as carbon sinks and are worth exploring for their potential in mitigating climate change. Variation partitioning shows that 26% of the variance in the diatom assemblages is associated with land use changes. The variables grassland, cropland, and stable nitrogen isotopes are accordingly strong predictors of environmental change in the Baltic coastal zone as reflected by the diatom assemblages.

The aim of this paper is to show different patterns for decomposition of the main mass of needle litter from two boreal and temperate coniferous tree species, both leading to a stabilized fraction of litter. To this purpose we have reviewed information on decomposition patterns in the lignin-dominated (late) stages of two local foliar litter types, namely those of Scots pine (Pinus silvestris) and Norway spruce (Picea abies) from two climatic gradients of equal extension. We have also reviewed factors determining the limit values for both species.

Long-term decomposition studies were used to calculate annual mass loss in the lignin-dominated decomposition stage and relate these to mean annual temperature (MAT), mean annual precipitation (MAP) and concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn) and acid unhydrolyzable residue (gravimetric lignin, AUR).

There was no effect of MAT on decomposition of either needle litter type. MAP had a rate-dampening effect on decomposition of Norway spruce litter. There was a rate-stimulating effect of Mn for Norway spruce litter but not for that of Scots pine. In spite of the strong negative effect of AUR and N on decomposition of Scots pine litter there was none at all for that of Norway spruce.

Limit values for decomposition were related to the litters’ initial concentrations of N, Mn and AUR and differed between litter types for locally collected, natural litter and for that from experimental litter, the latter having higher N and lower Mn concentrations than the natural litter.

We conclude that the two litter types have clear differences as regards rate- regulating factors for decomposition in the late lignin-dominated stage as well as for the stable fraction and suggest two different pathways for their decomposition. This is the first time that different pathways have been suggested for decomposing litter.

We have reviewed information on early-, late- and limit-value decomposition stages for litter of Norway spruce (Picea abies) and Scots pine (Pinus silvestris). This synthesis covers c 16 studies/papers made along a climatic gradient; range in mean annual temperature (MAT) from −1 to +7 °C and mean annual precipitation (MAP) from 425 to 1070 mm. Scots pine has an early stage dominated by carbohydrate decomposition and a late stage dominated by decomposition of lignin; Norway spruce has just one stage dominated by lignin decomposition. We used data for annual mass loss to identify rate-regulating factors in both stages; climate data, namely, MAT and MAP, as well as substrate properties, namely, nitrogen (N), acid unhydrolyzable residue (AUR), manganese (Mn). Early-stage decomposition for Scots pine litter was dominated positively by MAT; the late stage was dominated negatively by MAT, N, and AUR, changing with decomposition stage; there was no effect of Mn. Norway spruce litter had no early stage; decomposition in the lignin-dominated stage was mainly negative to MAP, a negative relationship to AUR and non-significant relationships to N and MAT. Mn had a positive relationship. Limit values for decomposition, namely, the accumulated mass loss at which decomposition is calculated to be zero, were related positively to Mn and AUR for Scots pine litter and negatively to AUR for Norway spruce litter. With different sets of rate-regulating factors as well as different compounds/elements related to the limit values, the decomposition patterns or pathways are different.

Native wild boar (Sus scrofa) populations are expanding across Europe. This is cause for concern in some areas where overabundant populations impact natural ecosystems and adjacent agronomic systems. To better manage the potential for impacts, managers require more information about how the species may affect other organisms. For example, information regarding the effect of wild boar on soil fungi for management application is lacking. Soil fungi play a fundamental role in ecosystems, driving essential ecological functions; acting as mycorrhizal symbionts, sustaining plant nutrition and providing defense; as saprotrophs, regulating the organic matter decomposition; or as plant pathogens, regulating plant fitness and survival. During autumn (Sep–Nov) 2018, we investigated the effects of wild boar (presence/absence and rooting intensity) on the abundance (number of individuals) of fungal sporocarps and their functional guilds (symbiotic, saprotrophic and pathogenic). We selected eleven forested sites (400–500 × 150–200 m) in central Sweden; six with and five without the presence of wild boar. Within each forest, we selected one transect (200 m long), and five plots (2 × 2 m each) for sites without wild boar, and ten plots for sites with boars (five within and five outside wild boar disturbances), to determine the relationship between the intensity of rooting and the abundance of sporocarps for three fungal guilds. We found that the presence of wild boar and rooting intensity were associated with the abundance of sporocarps. Interestingly, this relationship varied depending on the fungal guild analyzed, where wild boar rooting had a positive correlation with saprophytic sporocarps and a negative correlation with symbiotic sporocarps. Pathogenic fungi, in turn, were more abundant in undisturbed plots (no rooting) but located in areas with the presence of wild boar. Our results indicate that wild boar activities can potentially regulate the abundance of fungal sporocarps, with different impacts on fungal guilds. Therefore, wild boar can affect many essential ecosystem functions driven by soil fungi in boreal forests, such as positive effects on energy rotation and in creating mineral availability to plants, which could lead to increased diversity of plants in boreal forests.

We synthesized available data for magnesium (Mg) dynamics in newly shed and decomposing foliar litter of mainly pine (Pinus) species, Norway spruce (Picea abies), and birch (Betula) species. Using original, measured data from 40 stands organized in climatic gradients we intended to determine patterns of Mg concentration and net release vs accumulated mass loss of the litter. This synthesis is likely the first synthesis of Mg dynamics in decomposing litter.

In paired stands, litter of both Norway spruce and lodgepole pine (Pinus contorta) had higher Mg concentrations than Scots pine (Pinus silvestris), with concentrations in Norway spruce litter even twice as high.

In decomposing litter, Mg concentrations followed a quadratic (X2-X) function vs accumulated mass loss and consequently had minima, different for Norway spruce and Scots pine litter. Out of 68 decomposition studies 53 gave minimum concentration. The Mg minimum concentration during decomposition was positively related to initial Mg concentration for Scots pine and Scots pine plus lodgepole pine but not for Norway spruce. The increase in concentration suggests that after the minimum Mg was temporarily limiting.

For Norway spruce litter there was a relationship between minimum concentration of Mg and the limit value. There was no such relationship for Scots pine and not for the combined pine data.

Magnesium net release started directly after the incubation and was linear to accumulated mass loss of litter, giving a slope coefficient (release rate) for each study. The net release rate was linear to initial Mg concentration and all studies combined gave a negative linear relationship.

Sediment cores from three sites along the east-coast of Sweden, north-western Baltic Proper, have been studied with respect to lithologies, geochemistry, and diatom assemblages to trace and date early human impact with emphasis on nutrient discharge. The three sites Braviken, Himmerfjarden, and Adfjarden, have been impacted to various degree during the last millennia by multiple stressors like excessive nutrient discharge and hazardous substances, leading to coastal hypoxia, eutrophication, and pollution. These stressors are mainly caused by drivers in the drainage area as increased human population, changed land use, and point sources as industries and a sewage treatment plant. Even though their detailed history differs, the results show similar general patterns for all three sites. We find no evidence in our data from the coastal zone supporting the hypothesis that the extensive areal distribution of hypoxia in the open Baltic Sea during the Medieval Climate Anomaly was caused by human impact. Timing of the onset of man-made eutrophication, as identified from delta N-15 and changes in diatom composition, differs between the three sites, reflecting the site specific geography and local environmental histories of these areas. The onset of eutrophication dates to similar to 1800 CE in Braviken and Himmerfjarden areas, and to similar to 1900 CE in the less urban area of Adfjarden. We conclude that the recorded environmental changes during the last centuries are unique in a thousand year perspective.

Connectivity plays an important role in shaping the genetic structure and in evolution of local adaptation. In the marine environment barriers to gene flow are in most cases caused by gradients in environmental factors, ocean circulation and/or larval behavior. Despite the long pelagic larval stages, with high potential for dispersal many marine organisms have been shown to have a fine scale genetic structuring. In this study, by using a combination of high-resolution genetic markers, species hybridization data and biophysical modeling we can present a comprehensive picture of the evolutionary landscape for a keystone species in the Baltic Sea, the blue mussel. We identified distinct genetic differentiation between the West Coast, Baltic Proper and Bothnian Sea regions, with lower gene diversity in the Bothnian Sea. Oceanographic connectivity together with salinity and to some extent species identity provides explanations for the genetic differentiation between the West Coast and the Baltic Sea (Baltic Proper and Bothnian Sea). The genetic differentiation between the Baltic Proper and Bothnian Sea cannot be directly explained by oceanographic connectivity, species identity or salinity, while the lower connectivity to the Bothnian Sea may explain the lower gene diversity. © 2016.

According to the Swedish curriculum for primary school it is important in science subjects to develop skills to observe, to describe the observations and to put them into a theoretical framework already starting year 1–3.

Thus, it may be important for the teacher not only to be accustomed to the methods of observing but also to be an expert on using these observations in order to design teaching situations where these skills may be developed.

Here we present a study where 25 pre-service primary school teacher students at the beginning of a 20 weeks course established a relation to a study site focused on ecological questions. The task during the first week of that course was to observe and describe two habitats in the field and suggest what abiotic and biotic factors that had shaped the variation focussing at competition as an important ecological factor. In order to connect those ecological aspects with evolutionary aspects, specimen of the common species in the two habitats were collected and brought to the lab where the students constructed phenetic trees based on morphology but also on ecologically relevant properties like roots/no roots, expecting the set-up to awake evolutionary reflection. A main goal with this week was to give the students tools to investigate nature – to observe and describe patterns and to explain them by observing abiotic and biotic variation and evolutionary features and limitations.

Later during the course we created other, often not obviously similar, situations where the students had the opportunity to use the experiences of this first training week. We used open questions for reflections and examinations in order to get written material to assess the development of the skills.

We found notable personal development in most students and a greater awareness about the importance of personal cognitive activities in order to create better understanding and ability to use achieved knowledge in different situations.

Human-derived environmental pollutants and nutrients that reach the aquatic environment through sewage effluents, agricultural and industrial processes are constantly contributing to environmental changes that serve as drivers for adaptive responses and evolutionary changes in many taxa. In this study, we examined how two types of point sources of aquatic environmental pollution, harbors and sewage treatment plants, affect gene diversity and genetic differentiation in the blue mussel in the Baltic Sea area and off the Swedish west coast (Skagerrak). Reference sites (REF) were geographically paired with sites from sewage treatments plant (STP) and harbors (HAR) with a nested sampling scheme, and genetic differentiation was evaluated using a high-resolution marker amplified fragment length polymorphism (AFLP). This study showed that genetic composition in the Baltic Sea blue mussel was associated with exposure to sewage treatment plant effluents. In addition, mussel populations from harbors were genetically divergent, in contrast to the sewage treatment plant populations, suggesting that there is an effect of pollution from harbors but that the direction is divergent and site specific, while the pollution effect from sewage treatment plants on the genetic composition of blue mussel populations acts in the same direction in the investigated sites.

Horizontal gene transfer involves the non-sexual interspecific transmission of genetic material. Even if they are initially functional, horizontally transferred genes are expected to deteriorate into non-expressed pseudogenes, unless they become adaptively relevant in the recipient organism. However, little is known about the distributions of natural transgenes within wild species or the adaptive significance of natural transgenes within wild populations. Here, we examine the distribution of a natural plant-to-plant nuclear transgene in relation to environmental variation within a wild population. Festuca ovina is polymorphic for an extra (second) expressed copy of the nuclear gene (PgiC) encoding cytosolic phosphoglucose isomerase, with the extra PgiC locus having been acquired horizontally from the distantly related grass genus Poa. We investigated variation at PgiC in samples of F. ovina from a fine-scale, repeating patchwork of grassland microhabitats, replicated within spatially separated sites. Even after accounting for spatial effects, the distributions of F. ovina individuals carrying the additional PgiC locus, and one of the enzyme products encoded by the locus, are significantly associated with fine-scale habitat variation. Our results suggest that the PgiC transgene contributes, together with the unlinked 'native' PgiC locus, to local adaptation to a fine-scale mosaic of edaphic and biotic grassland microhabitats.