Locations In Southern Sweden Research Articles

A study of security guard deployment and crime reduction in three locations in southern Sweden

A study of security guard deployment and crime reduction in three locations in southern Sweden

Maintaining an open landscape: Comparison of management methods for semi-natural grasslands: A Swedish multi-site study

Traditional management of semi-natural grasslands by grazing or annual mowing is not always feasible and the current study set out to evaluate alternative management methods. At eleven locations in southern Sweden, block experiments were conducted evaluating seven treatments in 5 m*20 m plots: grazing, annual mowing, annual spring burning, mowing every third year, mechanical removal of woody plants, herbicide control of woody plants, and untreated control. After approximately 13 years, trends for woody plants and species richness, and the occurrence of management-dependent plant species, low-grown species, and pollinator-attracting plant species were analysed. Overall, the annual mowing and grazing treatments resulted in fewer woody plants, the highest species richness, and more management-dependent, low-grown, and pollinator-attracting species. The untreated control plots showed the opposite effect, whereas less intense management (annual burning, mowing every third year, and mechanical and chemical treatments of woody plants) showed mixed and often intermediate effects. Compared to grazing and mowing, less intense management methods do not constitute long-term management alternatives to preserve typical features of species-rich grasslands. However, they may be short-term alternatives at sites where the recruitment of woody species is absent or rare. However, to prevent the encroachment of woody species, less intensive management might be a better long-term alternative at more productive sites with slow or inhibited woody species recruitment.

Strategies for deployment of reproductive material under supply limitations – a case study of Norway spruce seed sources in Sweden

ABSTRACT The aim of this study was to analyze and compare the performance of Norway spruce seed sources from Swedish stands of East European origin (SweEast) with material from Swedish (SweSO) and East European (EastSO) seed orchards, and with material from Swedish (SweS) and East European (EastS) unimproved stands. The seed sources were field tested at six locations in southern Sweden and assessed for growth and phenology. The assessment of growth traits indicated that trees from SweSO and EastSO had 9–15% greater growth with respect to tree height and diameter in comparison to trees from Swedish local unimproved stands (SweS). Trees from SweEast and EastS showed around 5–7% greater growth. With respect to phenological traits, the expected later bud burst for EastS and EastSO in comparison to SweS, SweSO and SweEast was verified. However, SweEast exhibited earlier bud burst compared to EastS than what could be explained by pollination by Swedish pollen. This was explained by early land race formation for that trait. A strong positive correlation was observed between bud burst and frost damage, which indicates that earlier bud burst does indeed increase the risk of damage from late spring frost at frost-prone sites.

Thinning around old oaks in spruce production forests: current practices show no positive effect on oak growth rates and need fine tuning

ABSTRACTThe expansion of spruce-dominated forestry in Southern Sweden during the twentieth century has led to a considerable amount of oak (Quercus robur L.) woodlands being converted into stands dominated by planted spruce. The thinning of spruces around oak trees is currently done in Sweden to improve local diversity of insects, oak growing conditions and eventually decrease their mortality. To evaluate the effect of these treatments, we dendrochronologically studied growth of old (100–200 years old) oaks subjected to thinning of different intensity at nine locations in southern Sweden, and compared them to oaks located in nearby pastures. The overall pattern suggests that commonly adopted thinning intensities do not significantly affect oak growth. Oak growth was positively related to oak age and negatively to the amount of dead oak crown. Analyses of correlations between oak growth and summer drought conditions, as reflected by location-specific chronologies of the Monthly Drought Code (MDC), indicated that older trees exhibited generally negative correlations, whereas the correlation remained generally positive for the younger trees, both inside and outside forest stands. We propose that removal of spruces should be primarily done around older and healthier-looking trees.

Concentrations, fluxes and field calibration of passive water samplers for pesticides and hazard-based risk assessment

Three passive sampler types including Chemcatcher® C18, polar organic chemical integrative sampler-hydrophilic–lipophilic balance (POCIS-HLB) and silicone rubber (SR) based on polydimethylsiloxane (PDMS) were evaluated for 124 legacy and current used pesticides at two sampling locations in southern Sweden over a period of 6 weeks and compared to time-proportional composite active sampling. In addition, an in situ calibration was performed resulting in median in situ sampling rates (RS, L day−1) of 0.01 for Chemcatcher® C18, 0.03 for POCIS-HLB, and 0.18 for SR, and median in situ passive sampler-water partition coefficients (log KPW, L kg−1) of 2.76 for Chemcatcher® C18, 3.87 for POCIS-HLB, and 2.64 for SR. Deisopropylatrazine D5 showed to be suitable as a performance reference compound (PRC) for SR. There was a good agreement between the pesticide concentrations using passive and active sampling. However, the three passive samplers detected 38 pesticides (including 9 priority substances from the EU Water Framework Directive (WFD) and 2 pyrethriods) which were not detected by the active sampler. The most frequently detected pesticides with a detection frequency of >90% for both sites were atrazine, 2,6-dichlorobenzamide, bentazone, chloridazon, isoproturon, and propiconazole. The annual average environmental quality standard (AA-EQS) for inland surface waters of the EU WFD and the risk quotient (RQ) of 1 was exceeded on a number of occasions indicating potential risk for the aquatic environment.

Population genetic structure, differentiation, and diversity in Tetrix subulata pygmy grasshoppers: roles of population size and immigration.

Genetic diversity within and among populations and species is influenced by complex demographic and evolutionary processes. Despite extensive research, there is no consensus regarding how landscape structure, spatial distribution, gene flow, and population dynamics impact genetic composition of natural populations. Here, we used amplified fragment length polymorphisms (AFLPs) to investigate effects of population size, geographic isolation, immigration, and gene flow on genetic structure, divergence, and diversity in populations of Tetrix subulata pygmy grasshoppers (Orthoptera: Tetrigidae) from 20 sampling locations in southern Sweden. Analyses of 1564 AFLP markers revealed low to moderate levels of genetic diversity (PPL = 59.5–90.1; Hj = 0.23–0.32) within and significant divergence among sampling localities. This suggests that evolution of functional traits in response to divergent selection is possible and that gene flow is restricted. Genetic diversity increased with population size and with increasing proportion of long‐winged phenotypes (a proxy of recent immigration) across populations on the island of Öland, but not on the mainland. Our data further suggested that the open water separating Öland from the mainland acts as a dispersal barrier that restricts migration and leads to genetic divergence among regions. Isolation by distance was evident for short interpopulation distances on the mainland, but gradually disappeared as populations separated by longer distances were included. Results illustrate that integrating ecological and molecular data is key to identifying drivers of population genetic structure in natural populations. Our findings also underscore the importance of landscape structure and spatial sampling scheme for conclusions regarding the role of gene flow and isolation by distance.

Impact of RCM Spatial Resolution on the Reproduction of Local, Subdaily Precipitation

Abstract Many hydrological hazards are closely connected to local precipitation (extremes), especially in small and urban catchments. The use of regional climate model (RCM) data for small-scale hydrological climate change impact assessment has long been nearly unfeasible because of the low spatial resolution. The RCM resolution is, however, rapidly increasing, approaching the size of small catchments and thus potentially increasing the applicability of RCM data for this purpose. The objective of this study is to explore to what degree subhourly temporal precipitation statistics in an RCM converge to observed point statistics when gradually increasing the resolution from 50 to 6 km. This study uses precipitation simulated by RCA3 at seven locations in southern Sweden during 1995–2008. A positive impact of higher resolution was most clearly manifested in 10-yr intensity–duration–frequency (IDF) curves. At 50 km the intensities are underestimated by 50%–90%, but at 6 km they are nearly unbiased, when averaged over all locations and durations. Thus, at 6 km, RCA3 apparently generates low-frequency subdaily extremes that resemble the values found in point observations. Also, the reproduction of short-term variability and less extreme maxima were overall improved with increasing resolution. For monthly totals, a slightly increased overestimation with increasing resolution was found. The bias in terms of wet fraction and wet spell characteristics was overall not strongly dependent on resolution. These metrics are, however, influenced by the cutoff threshold used to separate between wet and dry time steps as well as the wet spell definition.

Inheritance of growth and solid wood quality traits in a large Norway spruce population tested at two locations in southern Sweden

Unfavorable genetic correlations between growth and wood quality traits are one of the biggest challenges in advanced conifer breeding programs. To examine and deal with such correlation, increment cores were sampled at breast height from 5,618 trees in 524 open-pollinated families in two 21-year-old Norway spruce progeny trials in southern Sweden, and age trends of genetic variation, genetic correlation, and efficiency of selection were investigated. Wood quality traits were measured on 12-mm increment cores using SilviScan. Heritability was moderate (~0.4–0.5) for wood density and modulus of elasticity (MOE) but low (~0.2) for microfibril angle (MFA). Different age trends were observed for wood density, MFA, and MOE, and the lower heritability of MFA relative to wood density and MOE in Norway spruce contrasted with general trends of the three wood quality traits in pine. Genetic correlations among growth, wood density, MFA, and MOE increased to a considerably high value from pith to bark with unfavorable genetic correlations (−0.6 between growth and wood density, −0.74 between growth and MOE). Age–age genetic correlations reached 0.9 after ring 4 for diameter at breast height (DBH), wood density, MFA, and MOE traits. Early selections at ring 10 for diameter and at ring 6 or 7 for wood quality traits had similar effectiveness as selection conducted at reference ring 15. Selection based on diameter alone produced 19.0 % genetic gain in diameter but resulted in 4.8 % decrease in wood density, 9.4 % decrease in MOE, and 8.0 % increase in MFA. Index selection with a restriction of no change in wood density, MOE, and MFA, respectively, produced relatively lower genetic gains in diameter (16.4, 12.2, and 14.1 %, respectively), indicating such index selection could be implemented to maintain current wood density. Index selection using economic weights is, however, recommended for maximum economic efficiency.

Hydrotalea flava gen. nov., sp. nov., a new member of the phylum Bacteroidetes and allocation of the genera Chitinophaga, Sediminibacterium, Lacibacter, Flavihumibacter, Flavisolibacter, Niabella, Niastella, Segetibacter, Parasegetibacter, Terrimonas, Ferruginibacter, Filimonas and Hydrotalea to the family Chitinophagaceae fam. nov.

Three bacterial strains, designated CCUG 51397(T), CCUG 53736 and CCUG 53920, isolated from water samples taken at different locations in southern Sweden were studied to determine their taxonomic position using a polyphasic approach. Comparative analysis of 16S rRNA gene sequences showed that these bacteria had <93 % sequence similarity to all described species of the genera Sediminibacterium, Lacibacter, Flavihumibacter, Flavisolibacter, Niabella, Niastella, Segetibacter, Parasegetibacter, Terrimonas, Ferruginibacter, Filimonas and Chitinophaga. The three organisms grouped most closely with Sediminibacterium salmoneum NJ-44(T) but showed only 92.5 % sequence similarity to this strain, the only recognized species of this genus. The fatty acid profiles showed large amounts of iso-C₁₅:₀, iso-C₁₇:₀ 3-OH and iso-C₁₅:₁ G with smaller amounts of iso-C₁₅:₀ 3-OH, iso-C₁₆:₀ 3-OH and other fatty acids, which differentiated the novel strains from related genera. Biochemical tests performed on strains CCUG 51397(T), CCUG 53736 and CCUG 53920 also gave different results from those of Sediminibacterium salmoneum NJ-44(T) and other related genera. Based on this evidence, strains CCUG 51397(T), CCUG 53736 and CCUG 53920 represent a novel species of a new genus, for which the name Hydrotalea flava gen. nov., sp. nov. is proposed. The type strain of Hydrotalea flava is CCUG 51397(T) (=CCM 7760(T)). A formal allocation of the genera Sediminibacterium, Lacibacter, Flavihumibacter, Flavisolibacter, Niabella, Niastella, Segetibacter, Parasegetibacter, Terrimonas, Ferruginibacter, Filimonas and Chitinophaga to the family Chitinophagaceae fam. nov. is also proposed.

Interactions between soil scarification and Norway spruce seedling types

Interactions between scarification treatments and seedling types of Norway spruce were examined at two different locations in southern Sweden. The scarification treatments were not scarified control, mounding and soil inversion and the seedling types were a 10 week-old containerized seedling (mini seedling), a 2 year-old containerized seedling and a 2 year-old hybrid seedling, grown as a containerized seedling the first year and as a bare-root seedling the second year. Site preparation intensity had a greater effect on the mini seedlings. The results indicated that mini seedlings established faster in the soil inversion treatment compared to the larger seedling types. At the same seedling age, the mini seedlings had faster or similar growth rate as the containerized and the hybrid seedlings regardless of scarification treatment. Although mini seedlings grew as well as or even better than larger seedlings if they were successfully established, they were more sensitive to their planting environment and proper handling was critical. Problems with frost heaving and competing vegetation have to be taken into consideration when choosing site preparation method and seedling type.

Assessment of regional willow coppice yield in Sweden on basis of water availability

The aim of this paper is to assess the limitations by water on yield in southern Sweden on the basis of long-term records of precipitation and known water relations of willow. Data concerning relationship with water comes from a field experiment in central Sweden and data on yield, obtained in commercial cultivations, comes from a number of locations in southern Sweden. A simple water-limited yield model based on the concept of water-use efficiency was used to estimate regional production. The model showed good agreement with the actual yield at a large number of locations in southern Sweden. The model was then used to produce a map of average maximum stemwood production and it showed that the annual production would be 8–9 t ha in the northeastern part of southern Sweden, 9–10 t in eastern Sweden, 11–12 t in the very south and reach a maximum of 16–17 t in a narrow belt along the west coast. Relating these yield values to data, reported in literature regarding economics of short-rotation forestry, shows that water will be a critical factor in order to obtain good profitability in short-rotation forestry in Sweden.

Models for the vertical migration of 137Cs in the ground — a field study

Soil sampling was performed repeatedly at two locations in southern Sweden in order to study the behaviour of 137Cs at different times after deposition. At two locations in the city of Lund, in southern Sweden, sampling was done 5 and 7 years after the Chernobyl accident. The samples were analysed for 137Cs from nuclear weapons tests as well as 137Cs of Chernobyl origin and three different models were used to describe the vertical transport in the ground. The first study shows that the downward transport of caesium from the Chernobyl accident with time could be quantified in a simple model, valid for a few years of transport. In another model the relative amount of 137Cs at different depths was observed to change with time in a predictable way and the depth of maximum activity was shown to move downwards with a mean speed of 0·2 cm year -1. A simple compartment model has also been tested.

Influence of weather on the efficacy of dichlorprop‐P/MCPA and trihenuron‐methyl

SummaryThe influence of weather on the efficacy of dichlorprop‐P/MCPA and tribenuron‐methyl on annual weeds in spritig barley was studied in the field during 4 years at six locations in southern Sweden. The herbicides were applied at one‐eighth to three‐quarters of the full dose at three application times with approximately 6‐day intervals. Weather stations, placed in the experiments, recorded climatic data, Maximum herbicide efficacy was obtained when spraying 1 week after the cotyledon stage with half or three‐quarters of the recommended dose. Dose‐response curves were estimated and the ED80 doses were calculated. On average, the herbicide dose required to obtain an effect of 80% was about 40% of the recommended dose. The influence of weather was analysed for seven different periods: 7 and 2 days before and after herbicide application, 1 day before and after application, and the day of herbicide treatment. The most pronounced eftects of weather were found for the day of and the day before herbicide application, revealing the strong influence of weather on herbicide uptake and plant metabolism. High air tetnperature and low global radiation during the day of treattnent reduced the ED80 dose of dichlorprop‐P/MCPA, whereas the ED80 dose of tribenuron‐methyl increased. For both herbicides, precipitation and high soil temperature increased the ED80 dose, which reflects the importance of rain on herbicide uptake and the effect of soil temperature on plant growth. The R2 values were higher in the analyses of dichlorprop‐P/MCPA than of tribenuron‐methyl, indicating that the effect of dichlorprop‐P/MCA was more weather‐dependent than that of tribenuron‐methyl. Separate analyses of the ED80 doses for Brassica napus L., Chenopodium, album L. and Stellaria media (L.) Vill. generally resulted in increased R2 values. but otherwise gave results similar to those for the total weed population. Although the analyses revealed significant effects of indivtdual weather factors on herbicide efficacy, it was not possible to discern a consistent and causal relationship between weather and herbicide performance.

Impact of clone mixture composition on stability of 7th-year mean height in a series of Norway spruce clone tests

Four mixtures of Norway spruce (Piceaabies (L.) Karst.), each containing 56 clones, were analysed for height at age 7 years at six locations in southern Sweden. The number of clones in each mixture was subsequently reduced in a stepwise manner from 56 to 40, 30, 20, 10, and finally, 5 clones. The reduction process was conducted in three ways: (i) random deletion, (ii) deletion based on height growth, and (iii) deletion based on clone stability. No difference among the means of clone mixtures could be found for 20–56 clones for any elimination procedure tested, and no mixture × location interaction existed despite the number of clones in the mixture or the elimination process used. Location effects were consistently significant, independent of the number of clones in each mixture. Also, replication effects were significant in all cases but one. Random elimination of clones resulted in weak differences between mixture means when 10 and 5 clones were included. Deletion of clones based on lack of stability or inferior height growth only slightly changed the variation pattern compared with when all 56 clones were present in each mixture. Relative height growth performance of clone mixtures with as few as 5 clones appeared to be stable within the region of Sweden that was represented by the trials.

Trends in genetic and environmental parameters, genetic correlations, and response to indirect selection for 10-year volume in a Norway spruce clonal experiment

Seventy-five clones of Norway spruce (Piceaabies (L.) Karst.) were tested for height, diameter, and volume at two locations in southern Sweden. Total height was measured at seven ages from age 1 to 10 years, whereas diameter at breast height was measured and volume index calculated only at age 10. Clone effects were consistently significant for all traits, whereas clone × location interaction effects only showed significance for diameter at breast height at age 10, volume index, and height at age 3. Location effects for height were small and error effects large, up to age 6. Between ages 7 and 10, location effects increased considerably, while error effects decreased correspondingly. Clone-mean heritability for height remained stable from years 3 to 10, but was slightly higher at age 1. Genetic correlations between traits were generally large, which made efficient selection for height possible as early as age 4. The correlated response in volume index at age 10, when selecting for height at age 4 or later, was exceptionally good, and it provided gain estimates in volume that were as large as or larger than estimates from direct selection for volume index at age 10.

Uptake of dry-deposited radionuclides in Fucus—A field study after the Chernobyl accident

The dry deposition of various radionuclides emanating from the plume from the Chernobyl reactor accident was measured at two locations in southern Sweden at the beginning of May, 1986. Samples of Fucus, taken at or near these locations, were also analysed. No precipitation had fallen during the time between the accident and the time of sampling. The ratios between activity concentrations in Fucus and dry depositions on the water surface have been calculated. For any specific radionuclide, this ratio was found to be the same at the two locations, after differences in salinity and in uptake between F. vesiculosus and F. serratus had been taken into account.

An investigation into regional transport of soot and sulfate aerosols

Daily measurements of soot and sulfate aerosols at urban and nonurban locations in Southern Sweden are used to demonstrate that an appreciable long range transport of these substances takes place with source regions in the SE-SW directions. Comparison with anthropogenic emissions shows that distant sources—more than 1000 km away—give significant contributions. The rate of formation of sulfate aerosols from oxidation of SO 2 has been studied. It has been found that, as a mean value for Swedish towns, only about 5 per cent of the emitted sulfur has been oxidized and formed sulfate aerosols within the first tens of minutes that the air parcel is still within the town. Total aerosol concentration has been estimated from visibility observations. A clear correlation between sulfate concentration and total aerosol mass has been found, although the mass of sulfate ions was only a small fraction of the total aerosol mass.