Ecosystem recharge by volcanic dust drives broad-scale variation in bird abundance

Across the globe, deserts and volcanic eruptions produce large volumes of atmospheric dust, and the amount of dust is predicted to increase with global warming. The effects of long-distance airborne dust inputs on ecosystem productivity are potentially far-reaching but have primarily been measured in soil and plants. Airborne dust could also drive distribution and abundance at higher trophic levels, but opportunities to explore these relationships are rare. Here we use Iceland's steep dust deposition gradients to assess the influence of dust on the distribution and abundance of internationally important ground-nesting bird populations. Surveys of the abundance of breeding birds at 729 locations throughout lowland Iceland were used to explore the influence of dust deposition on bird abundance in agricultural, dry, and wet habitats. Dust deposition had a strong positive effect on bird abundance across Iceland in dry and wet habitats, but not in agricultural land where nutrient levels are managed. The abundance of breeding waders, the dominant group of terrestrial birds in Iceland, tripled on average between the lowest and highest dust deposition classes in both wet and dry habitats. The deposition and redistribution of volcanic materials can have powerful impacts in terrestrial ecosystems and can be a major driver of the abundance of higher trophic-level organisms at broad spatial scales. The impacts of volcanic ash deposition during eruptions and subsequent redistribution of unstable volcanic materials are strong enough to override effects of underlying variation in organic matter and clay content on ecosystem fertility. Global rates of atmospheric dust deposition are likely to increase with increasing desertification and glacier retreat, and this study demonstrates that the effects on ecosystems are likely to be far-reaching, both in terms of spatial scales and ecosystem components

Arranging childcare in two Nordic countries: A comparison of ECEC start in Iceland and Sweden

Objective: The study examines the age children in Iceland and Sweden start Early Childhood Education and Care (ECEC) and how children's starting age is associated with parents' use of paid parental leave and their characteristics. Background: While children in Iceland have no legal rights to ECEC following the end of paid parental leave, in Sweden there is a continuum between paid parental leave and publicly subsidised ECEC. The leave period is also shorter in Iceland than in Sweden. The article addresses how these policy differences reflect the transition from paid parental leave to ECEC-start in the two countries. Method: The study uses survey data, collected among parents in Iceland and Sweden. Results: Children in Iceland have an earlier ECEC start than children in Sweden. This earlier start, however, has to do with the number of children being placed in family day care while waiting for a place in the public run preschools. Mothers in Iceland stretch the parental leave for a longer period than mothers in Sweden do, and in Iceland, there were variations in ECEC start depending on mothers’ labour force participation before childbirth and marital status, but not in Sweden. Conclusion: The lack of preschool at the end of paid parental leave creates challenges for a certain group of parents in Iceland, a situation parents in Sweden do not have to face.Fragestellung: Die Studie untersucht das Alter, in dem Kinder in Island und Schweden mit der frühkindlichen Betreuung, Bildung und Erziehung („ECEC“) beginnen, und wie das Eintrittsalter der Kinder mit der Inanspruchnahme von Elternzeit und den Merkmalen der Eltern zusammenhängt. Hintergrund: Während Kinder in Island nach dem Ende der bezahlten Elternzeit keinen Rechtsanspruch auf ECEC haben, gibt es in Schweden mehrere Möglichkeiten zwischen bezahltem Elternurlaub und öffentlich subventionierter ECEC. Die Dauer der Elternzeit ist in Island kürzer als in Schweden. Der Artikel untersucht, wie sich diese Unterschiede beim Übergang von bezahlter Elternzeit in die frühkindliche Bildung in den beiden Ländern widerspiegeln. Methode: Die Studie basiert auf Umfragedaten isländischer und schwedischer Eltern. Ergebnisse: Kinder in Island beginnen früher mit ECEC als Kinder in Schweden. Dieser frühere Beginn hängt damit zusammen, dass viele Kinder in Kindertagesstätten untergebracht werden, während sie auf einen Platz in den öffentlichen Kindergärten warten. Mütter in Island ziehen ihre Elternzeit über einen längeren Zeitraum als Mütter in Schweden, und in Island, aber nicht in Schweden, zeigen sich Unterschiede beim Einstiegsalter in ECEC nach der Erwerbsbeteiligung der Mutter vor der Geburt der Kinder und den Familienstand. Schlussfolgerung: Das Fehlen von Kinderbetreuung am Ende der bezahlten Elternzeit ist für bestimmte isländische Eltern eine Herausforderung, mit der sich Eltern in Schweden nicht auseinandersetzen müssen

Transferring avalanches between paths

Estimates of exceedance probabilities of runout lengths of avalanches for a specific path can rarely be based on measured avalanches in that slope alone, if they are to become statistically reliable. Thus one has, directly or indirectly, to include information of known runout lengths in other paths, i.e. to transfer runout lengths between paths. An attempt is made to classify such transfer methods, including both topographical methods that only make use of information on the shape of the path, such as methods based on runout ratios and a/ß-models, as well as physical methods which also make use of physical models, simulating the avalanche as it runs down the path. By introducing a specific standard slope all avalanches in a given dataset can be transferred to that slope. The length of the transferred avalanche in the standard slope then becomes a slope-independent measure of its length. Using an Icelandic dataset of 196 avalanches we demonstrate how estimates of exceedance probabilities of run out lengths may vary with the choice of transfer method and how the order of the slope-independent lengths of the avalanches in the dataset will vary. The implication for avalanche risk assessment is briefly discussed

The Icelandic volcanic aeolian environment: Processes and impacts — A review

Iceland has the largest area of volcaniclastic sandy desert on Earth or 22,000 km2. The sand has been mostly produced by glacio-fluvial processes, leaving behind fine-grained unstable sediments which are later re-distributed by repeated aeolian events. Volcanic eruptions add to this pool of unstable sediments, often from subglacial eruptions. Icelandic desert surfaces are divided into sand fields, sandy lavas and sandy lag gravel, each with separate aeolian surface characteristics such as threshold velocities. Storms are frequent due to Iceland’s location on the North Atlantic Storm track. Dry winds occur on the leeward sides of mountains and glaciers, in spite of the high moisture content of the Atlantic cyclones. Surface winds often move hundreds to more than 1000 kg m−1 per annum, and more than 10,000 kg m−1 have been measured in a single storm. Desertification occurs when aeolian processes push sand fronts and have thus destroyed many previously fully vegetated ecosystems since the time of the settlement of Iceland in the late ninth century. There are about 135 dust events per annum, ranging from minor storms to >300,000 t of dust emitted in single storms. Dust production is on the order of 30–40 million tons annually, some traveling over 1000 km and deposited on land and sea. Dust deposited on deserts tends to be re-suspended during subsequent storms. High PM10 concentrations occur during major dust storms. They are more frequent in the wake of volcanic eruptions, such as after the Eyjafjallajökull 2010 eruption. Airborne dust affects human health, with negative effects enhanced by the tubular morphology of the grains, and the basaltic composition with its high metal content. Dust deposition on snow and glaciers intensifies melting. Moreover, the dust production probably also influences atmospheric conditions and parameters that affect climate change.Peer Reviewe

Editorial

Because of the systemic connections between soils and many other issues, the attention that is actually paid to soil issues is far greater than is immediately apparent. In many countries, scientists, public servants and politicians are debating sequestration of carbon in soils, deforestation and other land management matters which impact the soil, the atmosphere and the human interests bound up in these.This special edition arose from a workshop held in Iceland in 2012, supported by the Australian Research Council and hosted by the Icelandic Soils Service. It brought together researchers and practitioners with expertise and interest in the human dimensions of natural resource governance. An aim was to generate fresh perspectives on how to govern human behaviour, to improve the sustainability and fairness of our use of the land. The team included experts and practitioners in soil issues, community engagement, psychology, sociology, economics, law and other disciplines from many countries. The papers in this special edition reflect issues that have also been canvassed in other investigations. These papers provide some different perspectives as well as reinforcing some common themes

Soil Carbon Accumulation and CO 2

Experimental plots were established on severely eroded land surfaces in Iceland in 1999 to study the rates and limits of soil carbon sequestration during restoration and succession. The carbon content in the upper 10 cm of soils increased substantially during the initial eight years in all plots for which the treatments included both fertilizer and seeding with grasses, concomitant with the increase in vegetative cover. In the following five years, however, the soil carbon accumulation rates declined to negligible for most treatments and the carbon content in soils mainly remained relatively constant. We suggest that burial of vegetated surfaces by aeolian drift and nutrient limitation inhibited productivity and carbon sequestration in most plots. Only plots seeded with lupine demonstrated continued long-term soil carbon accumulation and soil CO2 flux rates significantly higher than background levels. This demonstrates that lupine was the sole treatment that resulted in vegetation capable of sustained growth independent of nutrient availability and resistant to disruption by aeolian processes

Magnetic order and energy-scale hierarchy in artificial spin ice

In order to explain and predict the properties of many physical systems, it is essential to understand the interplay of different energy-scales. Here we present investigations of the magnetic order in thermalised artificial spin ice structures, with different activation energies of the interacting Ising-like elements. We image the thermally equilibrated magnetic states of the nano-structures using synchrotron-based magnetic microscopy. By comparing results obtained from structures with one or two different activation energies, we demonstrate a clear impact on the resulting magnetic order. The differences are obtained by the analysis of the magnetic spin structure factors, in which the role of the activation energies is manifested by distinct short-range order. This demonstrates that artificial spin systems can serve as model systems, allowing the definition of energy-scales by geometrical design and providing the backdrop for understanding their interplay.Comment: 8 pages, 5 figures (+ supplementary 6 pages, 4 figures

The importance of the weak: Interaction modifiers in artificial spin ices

The modification of geometry and interactions in two-dimensional magnetic nanosystems has enabled a range of studies addressing the magnetic order, collective low-energy dynamics, and emergent magnetic properties, in e.g. artificial spin ice structures. The common denominator of all these investigations is the use of Ising-like mesospins as building blocks, in the form of elongated magnetic islands. Here we introduce a new approach: single interaction modifiers, using slave-mesospins in the form of discs, within which the mesospin is free to rotate in the disc plane. We show that by placing these on the vertices of square artificial spin ice arrays and varying their diameter, it is possible to tailor the strength and the ratio of the interaction energies. We demonstrate the existence of degenerate ice-rule obeying states in square artificial spin ice structures, enabling the exploration of thermal dynamics in a spin liquid manifold. Furthermore, we even observe the emergence of flux lattices on larger length-scales, when the energy landscape of the vertices is reversed. The work highlights the potential of a design strategy for two-dimensional magnetic nano-architectures, through which mixed dimensionality of mesospins can be used to promote thermally emergent mesoscale magnetic states.Comment: 17 pages, including methods, 4 figures. Supplementary information contains 16 pages and 15 figure

The Spatial Variation of Dust Particulate Matter Concentrations during Two Icelandic Dust Storms in 2015

Particulate matter mass concentrations and size fractions of PM1, PM2.5, PM4, PM10, and PM15 measured in transversal horizontal profile of two dust storms in southwestern Iceland are presented. Images from a camera network were used to estimate the visibility and spatial extent of measured dust events. Numerical simulations were used to calculate the total dust flux from the sources as 180,000 and 280,000 tons for each storm. The mean PM15 concentrations inside of the dust plumes varied from 10 to 1600 µg·m−3 (PM10 = 7 to 583 µg·m−3). The mean PM1 concentrations were 97–241 µg·m−3 with a maximum of 261 µg·m−3 for the first storm. The PM1/PM2.5 ratios of >0.9 and PM1/PM10 ratios of 0.34–0.63 show that suspension of volcanic materials in Iceland causes air pollution with extremely high PM1 concentrations, similar to polluted urban areas in Europe or Asia. Icelandic volcanic dust consists of a higher proportion of submicron particles compared to crustal dust. Both dust storms occurred in relatively densely inhabited areas of Iceland. First results on size partitioning of Icelandic dust presented here should challenge health authorities to enhance research in relation to dust and shows the need for public dust warning systems.Peer Reviewe