Reduced community diversity in semi-natural meadows in southern Sweden, 1965–1990

Two data sets, one from the 1960s and one from 1990, from continuously managed semi-natural meadows (semi-natural grasslands used for hay-cutting) in Småland, southern Sweden, were analysed to describe the vegetation and in an attempt to characterise changes that have occurred in the vegetation. Based on a classification of the data set, nine plant communities were recognised. The main vegetational differences, as revealed by an ordination, were due to variation in soil moisture, which ranged from wet to dry.During the investigation period, the amount of hay meadow area decreased, particularly the area of wet-moist meadows. In addition, the total variation in the vegetation diminished, and three plant communities more or less disappeared. The turnover index of species in the data set was 36%, and most of the species that were lost had initially been uncommon. Lost species included rare taxa, such as Gentianella campestris and Linum catharticum, while the new species tended to be common in the region. Annual and biennial species accounted for a greater proportion of the lost taxa than did perennial species. The mean cover of species per plot and the relative abundance of graminoids per plot increased.The recorded changes in the vegetation may be related to the increased loads of nitrogen pollutants as well as to a decrease in management intensity. The diminished area is related to changes in land-use. The meadow sites in Småland have been part of a landscape rich in grasslands, but today they have a more or less relict status. They differ from grasslands found elsewhere in Sweden and Scandinavia. In Sweden, the majority (68%) of endangered vascular plants belong to the agricultural landscape. To ensure the survival of individual species it is important to preserve all types of meadows, not only a few selected ones, since no two meadows are alike.     

Trends in cereal cultivation in the Czech Republic from the Neolithic to the Migration period (5500 b.c.–a.d. 580)

This study summarises the current state of research on cultivated cereals from archaeological sites in the Czech Republic. We discuss the first appearances of particular cereals, their first proven cultivation (which usually happens much later) and their part within cereal husbandry. The questions of possible contamination of archaeobotanical material and problems concerning the identification of some cereal taxa are related to this topic. Trends in the importance of the cultivation of individual cereals are shown with generalized linear models (GLMs), based on an assemblage of 81 newly sampled sites. The results of GLM enable the division of the cereals into four groups characterised by: (1) species showing a gradual decrease in importance—Triticum monococcum (einkorn) and T. dicoccum (emmer), (2) species with progressively accumulating representation on sites during prehistory—Hordeum vulgare (common barley) and T. spelta (spelt), (3) those with a marked increase by the end of prehistory—T. aestivum/turgidum (naked wheat), Avena sp. (oats) and Secale cereale, (rye) and (4) a specific group including only Panicum miliaceum (broomcorn millet). There is a gradual increase in the diversity of cultivated cereals through time, starting with T. monococcum and T. dicoccum, followed by Hordeum, Panicum, T. spelta and T. aestivum/turgidum, Secale and Avena. Comparison of the chronological development of cereal cultivation in the area of the Czech Republic and surrounding countries shows a general correspondence with the trends observed in other parts of eastern-central Europe, although with some local specific differences.     

Pollen-landscape relationships in modern analogues of ancient cultural landscapes in southern Sweden — a first step towards quantification of vegetation openness in the past

This study aims to analyse how vegetation, and in particular the degree of openness of the landscape, is reflected in pollen assemblages from surface sediment in lakes. Modern analogues of ancient cultural landscapes in southern Sweden were selected. Surface sediments from 22 small lakes (0.5–20 ha) located mainly in the forest region of southern Sweden were collected and analysed for pollen in order to enlarge and complement an earlier data set of 13 lakes collected in the open, agricultural region of southernmost Sweden. The composition of the landscape surrounding the lakes was mapped within 1000-m and 500-m radii around the lakes using Colour InfraRed (CIR) aerial photographs. The pollen and landscape data were analysed using numerical ordination techniques. The results show that, despite the large variation of landscape openness, the variation in non-arboreal pollen (NAP) is low between the sites which was not the case for the 13 lakes of the previous study. It is hypothesised that this may be due to differences in the major characteristics of the two regions in which the sites were selected, i.e. mainly treeless and intensively farmed in the previous study and mainly forested in the present investigation. The difference in background pollen appears to play a decisive role on the relative representation of NAP. This implies that the background pollen should be estimated before NAP percentages can be used for quantitative reconstruction of past landscape openness. In the 22 lakes studied, Gramineae, Cerealia (excludingSecale),Filipendula andSalix are positively correlated to cultivated land within both radii, and with open land (tree cover not exceeding 20%) within the 1000-m radius.Quercus andFagus have some positive correlation with deciduous orest within 1000-m radius. We conclude that the landscape units cultivated land, open land and deciduous forest within 1000-m radius are reasonably well reflected in the pollen assemblages and could be predicted within this area.     

Long-term history of land-use and vegetation at Femtingagölen — a small lake in the Småland Uplands, southern Sweden

Pollen analysis was carried out on gyttja from the small lake Femtingagölen in the Småland Uplands, southern Sweden. The interpretation of the pollen diagram focused on land-use history and comparisons were made to archaeological and historical information from the area. An absolute chronology, based on AMS dates from terrestrial plant macrofossils, was complemented by inferred dates. The pollen analytical data suggest interference with the woodland cover from ca. 1700 B.C. onwards. Intensified grazing and forest clearances resulted in semi-open pastures between ca. A.D. 400–600 which was followed by forest regeneration (chronology based on AMS ¹⁴C dates and cross-correlation with other well dated profiles). The landscape became more open again between A.D. 800 and 1400. Animal husbandry was complemented by small-scale shifting cultivation during the Iron Age. Permanent arable fields were probably not introduced until the Late Iron Age or the Middle Ages. Hordeum and Triticum were grown during the Iron Age, Hordeum, Triticum, Secale and Cannabis sativa during the Middle Ages and early Modern time, and Hordeum and Avena in the recent past. Sandy and silty soils, where stone clearance was not necessary, have probably been used for cereal growing in prehistoric and historic time.     

Room at the top? Minority mobility and the transition to demographic diversity in the USA

We examine the ramifications of the demographic transition to diversity in the USA through an analysis of changes at the top of the occupational hierarchy, as glimpsed in recent census data. We find evidence that, among the incumbents of better-paid occupations, the percentage of non-Hispanic whites, the historically dominant majority, is sharply declining, while the proportion of immigrant-origin minorities, Asians, both foreign and US born, and US-born Hispanics, is growing. African Americans, or US-born blacks, are not so far sharing much in this growth. However, whites still retain important advantages in terms of occupational placement net of education and in terms of earnings net of occupational placement. We conclude overall that demographic shifts are highly likely to drive further diversification at the top of the US workforce; the question of whether whites can hold on to their advantages in the face of these changes cannot be answered yet.     

What factors influence the diversity of saproxylic beetles? A multiscaled study from a spruce forest in southern Norway

The diversity in different groups of obligate saproxylic beetles was related to ecological variables at three levels of spatial scale in mature spruce-dominated forest. The variables were connected to: (i) decaying wood, (ii) wood-inhabiting fungi, (iii) the level of disturbance, (iv) landscape ecology, and (v) vegetational structure. Several strong relationships were found at medium (1 km²) and large scales (4 km²), while only weak relationships were found at a small scale (0.16 ha; 1 ha=10⁴ m²). This may be explained by the local variations in habitat parameters and the high mobilities of many beetle species. Factors connected to decaying wood and wood-inhabiting fungi were clearly the most important factors at all scale levels. In particular, the variables diversity of dead tree parts, number of dead trees of large diameter and number of polypore fungi species increased the species richness of many groups and increased the abundance of many species. Eight species were absent below a certain density of decaying wood per 1 or 4 km². Former extensive cutting was a negative factor at large scale, probably because of decreasing recolonization with increasing distance to the source habitats. Thinning reduced the diversity of species associated with birch. The development of guidelines favouring the diversity of saproxylic beetles are discussed below.     

Farming in a rural settlement in central Italy: cultural and environmental implications of crop production through the transition from Lombard to Frankish influence (8th–11th centuries a.d.)

Plant macrofossil (carpological) and morphometric analyses were carried out on plant remains from the medieval castle of Miranduolo, Siena, a rural settlement in central Italy with a long sequence of occupation between the 8th and the 11th centuries a.d. The presence of Triticum aestivum/durum and Vicia faba var. minor from the first phase of the Lombard farming village suggests continuity with the agricultural tradition of the preceding Roman world, and the use of good cultivation techniques that allowed quality yields to be obtained from rather poor soils. At the same time, the significant presence of the primitive cereal T. monococcum, compared with the archaeobotanical literature of north-central Italy, allows to us consider it as a “cultural” element of Lombard farming. In the next cultural phases, with the Carolingian manor and then with the feudal castle, the stable presence of T. aestivum/durum and the reduction of T. monococcum in favour of more productive cereals such as Secale cereale and Hordeum vulgare indicate a further improvement in productivity. This is also confirmed by the appearance of fruits and nuts such as Castanea sativa, Vitis vinifera and Prunus persica. The increase in caryopsis sizes of T. monococcum and T. aestivum/durum in the transition from the village to the manorial phase is a consequence of the improvements in farming. The decrease in caryopsis size of T. monococcum from the manor phase to that of the castle testifies the decreasing importance of this cereal. The good date resolution of this research allows us to detect the crops, the storage and the processing practices, as well as the changing role of crop plants in the rural economy. This highlights the geographical, historical-cultural and political factors of the medieval transition from the Lombard to the Carolingian and then to the feudal period in central Italy.     

The role of threat to areas and initiative from actors for establishment of nature reserves in southern Sweden 1926–1996

Ecologists are developing methods for the design of reserve systems, but non-ecological factors or criteria may limit their applicability (e.g. threat, initiative, low-cost opportunities). Threat before reserve acquisition (i.e. direct threat, contributing to reserve establishment) and the actors proposing reserves were studied for a random sample of 84 nature reserves with forest in southern Sweden, established 1926–1996. A direct threat was recorded for about 40% of these reserves before they were acquired. The remaining reserves had not been directly threatened, although indirect threat probably contributed to establishment of several reserves. Threat was an important factor in this productive lowland area, but for reserves in larger regions with varied topography (e.g. Sweden) mainly alpine or low-productive areas is represented, and threat seems to be of minor importance. Decisions for the 84 reserves were taken by one main conservation agency, which however initiated less than 50% of the reserves. External actors, such as other authorities, idealistic organisations and private individuals were also important initiators, suggesting that actors in the reserve process should be studied in biodiversity programs. Strong arguments for protection, careful planning, and flexibility with respect to non-ecological factors (that probably cannot be eliminated) may be successful tactics to establish more reserves with high biological values.     

Lepidophylloides corumbataensis sp. nov. from the Guadalupian in the Paraná Basin,southern Brazil

A new species of the isoetalean leaf genus Lepidophylloides is described. This Guadalupian species from the Paraná Basin, Lepidophylloides corumbataensis, found as silicified microphylls in the Corumbataí Formation in the municipality of Piracicaba, São Paulo state, in southern Brazil, is the first species of the genus to be formally described for Brazil, and possibly the first for Gondwanaland. This is also the first time that surviving palisade tissue has been found in a species of Lepidophylloides. The new species is compared to known species and shown to be distinct from all previously described from Euramerican and Cathaysian floras. The organization of the xylem in arch-like or crescent-shaped bundles suggests a relation to Cathaysian species. The close association with Lycopodiopsis derbyi stems (which have true leaf scars and must have suffered leaf abscission) suggests that they are different organs from the same species.     

Bilateral versus Single Internal Mammary Coronary Artery Bypass Grafting in Sweden from 1997–2008

Background

Prior observational studies have suggested better outcomes in patients who receive bilateral internal mammary arteries (BIMA) during coronary artery bypass grafting (CABG) compared with patients who receive a single internal mammary artery (SIMA). The aim of this study was to analyze the association between BIMA use and long-term survival in patients who underwent primary isolated CABG.

Methods and Results

Patients who underwent primary isolated non-emergent CABG in Sweden between 1997 and 2008 were identified. The SWEDEHEART registry and other national Swedish registers were used to acquire information about patient characteristics and outcomes. Unadjusted and multivariable adjusted regression models were used to estimate the association between BIMA use and early mortality, long-term survival, and a composite of death from any cause or rehospitalization for myocardial infarction, heart failure, or stroke in the overall cohort and in a propensity score-matched cohort. The study population consisted of 49702 patients who underwent CABG with at least one internal mammary artery, and 559 (1%) of those had BIMA grafting. In the adjusted analyses, BIMA use was not associated with better survival compared with SIMA use in the overall cohort (hazard ratio (HR) for death: 1.16, 95% confidence interval (CI): 0.97 to 1.37) or in the matched cohort (HR: 1.04, 95% CI: 0.78 to 1.40). The results were similar for early mortality and the composite endpoint. Reoperation for sternal wound complications was more common among BIMA patients (odds ratio: 1.71, 95% CI: 1.01 to 2.88).

Conclusions

BIMA grafting was performed infrequently and was not associated with better outcomes compared with SIMA grafting in patients undergoing non-emergent primary isolated CABG in Sweden during 1997–2008.     

Disease and fertility: Evidence from the 1918–19 influenza pandemic in Sweden

What are the consequences of a severe health shock like an influenza pandemic on fertility? Using rich administrative data and a difference-in-differences approach, we evaluate fertility responses to the 1918–19 influenza pandemic in Sweden. We find evidence of a small baby boom following the end of the pandemic, but we show that this effect is second-order compared to a strong long-term negative fertility effect. Within this net fertility decline there are compositional effects: we observe a relative increase in births to married women and to better-off families. Several factors – including disruptions to the marriage market and income effects – contribute to the long-term fertility reduction. The results are consistent with studies that find a positive fertility response following natural disasters, but we show that this effect is short-lived.     

Population-wide incidence estimates for soft tissue knee injuries presenting to healthcare in southern Sweden: data from the Sk?ne Healthcare Register

Introduction

Soft tissue knee injury is a well-established and potent risk factor for development of knee osteoarthritis. However, there is a paucity of epidemiological data from the general population. Our aim was to estimate the annual person-level incidence for a wide spectrum of clinically diagnosed soft tissue knee injuries, and their distribution by age, sex, and season.

Methods

In Sweden, in- and outpatient health care is registered using each individuals’ unique personal identifier including International Classification of Diseases (ICD) 10 diagnostic code(s) as determined by physicians’ clinical examination. For the calendar years 2004–2012, we studied the population in southern Sweden, Skåne region (approx. 1.3 million). We identified residents who had at least one visit to a physician with clinically diagnosed knee ligament, meniscal, or other soft-tissue injury (S80.0, S83 and all subdiagnoses). We then calculated the mean annual incidence over the 9-year period. As a secondary objective, we investigated potential seasonal variation.

Results

The annual incidence for males and females was 766 (95% CI: 742, 789) and 676 (649, 702) per 100,000 persons/year respectively. For males and females, the peak rate occurred in 15 to 19 year-olds (1698 per 100,000 men and 1464 per 100,000 women, respectively). In women, rates were lowest in the 25 to 34 year-old age range before rising again between the ages of 35 and 49 years. We found substantial seasonal variation, greatest in men, with peaks in March-May and August-October.

Conclusions

The incidence of clinically diagnosed soft-tissue knee injury peaks in adolescence and emerging adulthood. However, a range of knee injuries continue to occur across the adult lifespan including at ages when osteoarthritis is typically diagnosed and managed. The potential cumulative effect on osteoarthritis progression of these injuries may warrant further investigation.

Electronic supplementary material

The online version of this article (doi:10.1186/ar4678) contains supplementary material, which is available to authorized users.     

How many demersal fish species in the deep sea? A test of a method to extrapolate from local to global diversity

Grassle and Maciolek (1992) estimated that there were of the order of 107 species of benthic macro-invertebrates in the world's deep sea soft sediments. Their estimate was extrapolated from the 798 species they sampled and the pattern of species diversity observed along a 176km transect on the continental slope of the northeast Atlantic Ocean. Relative to the deep sea invertebrate fauna, the deep sea fish fauna has been better sampled, at least in the upper 1500m. To test the validity of the Grassle and Maciolek method of extrapolation, we applied it to data from a survey of fishes along the continental slope off western Australia, a diverse and previously unsurveyed region. The resulting global estimate for the deep sea demersal fishes – 60000 species – was then compared with the number described to date, about 2650 species, and an estimate of total extant species. Our estimate, which considers the proportion of new species found in little-explored regions of the world ocean, such as off western Australia, and the number of new species expected in future taxonomic revisions, is a total of 3000–4000 species. The Grassle and Maciolek method appears invalid as a means to extrapolate global biodiversity from local surveys.     

A CAL program to teach the basic principles of genetic engineering—a change from the traditional approach

An interactive computer-assisted learning program written for the BBC microcomputer to teach the basic principles of genetic engineering is described. The pro-gram makes extensive use of colour, graphics, and animation and is aimed at A-level students of biology. Students select, from a menu, to investigate one of a number of identified processes involved in the overall production of a protein, each of which is treated as a self-contained unit. An assessment of how much of the factual information the student has learned is provided in the form of a computer 'adventure game' which is not only challenging but fun to play. Briefly, the student is led into an imaginary laboratory and must choose from shelves those essential items (e.g. reagents, starting materials, techniques) to progress through several stages culminating in the production of genetically engineered bacteria capable of producing a specific protein.     

Habitat preferences of red-listed fungi and bryophytes in woodland key habitats in southern Sweden – analyses of data from a national survey

The aim of this study was to identify habitat preferences of red-listedepiphytic and epixylic bryophyte, lichenized and non-lichenized fungi speciesinwoodland key habitats (WKHS) (areas less than 10 ha, where foreststructures indicate occurrence of red-listed species) in southern Sweden. Therelative importance of different groups of environmental factors was assessedwith partial canonical correspondence analysis techniques and across-validationapproach using data from 7196 selected WKHs. Different woody substrates (oldtrees, logs and snags) made up the most important variable group for occurrenceof red-listed species (30% unique explainable variation). Species associatedwith Fagus sylvatica and Picea abieshabitats, but also species associated with Quercus spp.andPopulus tremula habitats showed distinct habitatpreferences. The second most important variable group (16% unique explainablevariation) was geographical location. A west–east gradient was identified, andspecies concentrated to Baltic islands in the east were separated from otherspecies. This gradient, and an identified south–north gradient, probablyreflect differences in temperatures and rainfall between different regions.Among the remaining variable groups, historical land-use, ground conditions andforest stand composition were of similar importance (5–7% uniqueexplainable variation). Traditional management regimes resulting in semi-openforest habitats (leaf harvesting, forest grazing and selective cutting) wereassociated with the occurrence of many species, probably due to differences inmicroclimate between sites of different openness. Furthermore, a groundmoisturegradient extending from species associated with dry sites (mainly lichenizedfungi) to species associated with wet sites (mainly bryophytes), and a nutrientgradient from species associated with nutrient-poor sites to species occurringat nutrient-rich sites, were identified. Thus, conservation measures are neededin a broad spectrum of habitats with different substrates. Also sites withsimilar substrates, but situated in different regions (and climates), or withdifferent ground moisture and nutrient conditions are needed to cover the fullspectrum of habitat conditions suitable for different red-listed bryophytes andfungi.     

A tribute to Per Halldal (1922–1986), a Norwegian photobiologist in Sweden

We present here a tribute to Per Halldal (February 2, 1922–March 26, 1986), a leader, an instrumentalist, an expert on phototaxis in algae, and one whom we remember, even after 20 years of his death, as a person who spread joy, enthusiasm and knowledge wherever he went.