The hydrology and preservation condition in the flat-topped burial mound: Klangshøj at Vennebjerg in Vendsyssel

Klangshøj is a flat-topped burial mound similar to the Royal Jelling mounds, although smaller. The myths tell that a well has existed on top of the mound as at Jelling and a spring had flown at the base of the mound. In order to verify the myths and a similar hydrology in Klangshøj as found in Jelling, several borings have been carried out in a north-south line across the mound. The investigation showed that Klangshøj is built of sods mainly harvested from heathland. The sods are of different grain sizes from fine sand to clay. The preservation conditions were excellent in three of the six borings, where undecomposed plant remnants, occasionally greenish, were observed. A 14C-dating showed that the mound was built in the Viking Age. The hydrology in Klangshøj is the same as in the Jelling mounds, with a permeable bioturbation zone covering almost impermeable, distinct sod layers. This form a perched groundwater table in the transition zone, which keeps the distinct sod layer below anaerobic, i.e. the preservation conditions extremely favourable. The perched water table drains internally as in the Jelling mounds, and there are no current nor fossil evidence to suggest a spring was ever present at the foot slope, as the local legend suggests. Moreover, it seems unlikely that a well, similar to the one on the Jelling mound, has existed on the top of the north-facing slope, as the amount of water the well would have been able to collect is little

Development of a harmonised soil profile analytical database for Europe:a resource for supporting regional soil management

Soil mapping is an essential method for obtaining a spatial overview of soil resources that are increasingly threatened by environmental change and population pressure. Despite recent advances in digital soil-mapping techniques based on inference, such methods are still immature for large-scale soil mapping. During the 1970s, 1980s and 1990s, soil scientists constructed a harmonised soil map of Europe (1:1 000 000) based on national soil maps. Despite this extraordinary regional overview of the spatial distribution of European soil types, crude assumptions about soil properties were necessary for translating the maps into thematic information relevant to management. To support modellers with analytical data connected to the soil map, the European Soil Bureau Network (ESBW) commissioned the development of the soil profile analytical database for Europe (SPADE) in the late 1980s. This database contains soil analytical data based on a standardised set of soil analytical methods across the European countries. Here, we review the principles adopted for developing the SPADE database during the past five decades, the work towards fulfilling the milestones of full geographic coverage for dominant soils in all the European countries (SPADE level 1) and the addition of secondary soil types (SPADE level 2). We illustrate the application of the database by showing the distribution of the root zone capacity and by estimating the soil organic carbon (SOC) stocks at a depth of 1 m for Europe to be 60×1015 g. The increased accuracy, potentially obtained by including secondary soil types (level 2), is shown in a case study to estimate SOC stocks in Denmark. Until data from systematic cross-European soil-sampling programmes have sufficient spatial coverage for reliable data interpolation, integrating national soil maps and locally assessed analytical data into a harmonised database remains a powerful resource to support soil resources management at regional and continental scales by providing a platform to guide sustainable soil management and food production

Biogeochemistry in Subarctic birch forests : Perspectives on insect herbivory

Herbivory can influence ecosystem processes, partly through long-term changes of the plant community compositions, but also more rapidly through the herbivores’ digestive alteration of the organic matter that is cycled through the soil and back to the primary producers. In the Subarctic mountain birch (Betula pubescens ssp. czerepanovii) forest (SMBF) in Northern Fennoscandia, outbreaks by the geometrid moths (Epirrita autumnata and Operophtera brumata) are well-described, widespread, and increasing with global warming. In contrast, the ecosystem effects of background insect herbivory (BIH) in this ecosystem lacks quantification, although belowground responses to aboveground perturbations in high-latitude systems may accelerate global warming due to their storage of large terrestrial organic carbon (C) pools. We quantified the ecosystem impact of BIH in the SMBF of Northern Sweden. An initial literature review showed that the clear increase in organic matter turnover rates under insect infestations was primarily driven by outbreak conditions. In line with this, our conversion of an average BIH-rate of ~1.6% of the leaf area to annual canopy-tosoil fluxes of nitrogen (~3.5% N) and phosphorus (~2.0% P) showed that the background rates were relatively small compared to internal recycling through litter, and inputs from external sources, such as atmospheric deposition, biological fixation and weathering.In addition, we showed that the insects themselves efficiently conserve N, as 70-80 % of the ingested N was converted to insect biomass, while respiring 30-50% of the ingested C. When insect excreta (frass) was added to the soil, we showed that another ~30 % of the C was respired by soil organisms. Hence, a total of ~60 % of the C ingested by insect herbivores would be respired during the first growing season, compared to ~10 % of the C added as senesced litter, suggesting a decreased litter C-sink in soils during outbreaks. In microcosm incubations, frass addition stimulated fungal growth more than bacterial growth while litter addition showed the opposite relationship. In contrast, under non-outbreak conditions along natural environmental gradients in the SMBF, decomposer bacterial growth was strongly correlated with BIH and other indicators of labile organic substrates, while fungal growth showed very little correlation with the potential driver variables. Yet, BIH did not explain a significant portion of the variation in the fraction of microbially assimilated C that was incorporated into soil microbial biomass, i.e. the soil carbon use efficiency (CUE). CUE was strongly controlled by respiration, but when this was controlled for, it increased with both bacterial and fungal growth rates. Further, CUE decreased with increasing soil temperature and the size of the soil microbial biomass pool. This suggests decreased soil C-sequestration with global warming, although an associated decrease in microbial biomass, which is often observed in warming experiments, may moderate this effect. Finally, gross N-mineralisation was also substantially higher after addition of insect frass (~17 % of added N) compared to litter (lower than control), so the availability of mineral N is higher under insect outbreaks increasing the risk of leaching losses.Finally, we challenged the assumption underlying space-for-time substitution studies, i.e. that variation along natural elevational gradients is scale invariant and universal, by showing that e.g. BIH exhibit contrasting trends with local and regional elevation. Although explorative, these findings merit further considerations of when spacefor-time-substitution is a feasible tool for inferring ecosystem responses to environmental change

The north atlantic provenance database : An introduction

The amount of provenance information available for onshore and offshore sedimentary deposits in the North Atlantic Region is substantial and rapidly increasing. These data provide an improved understanding of reservoir geology (quality, diagenetic issues, regional source-to-sink relations and local stratigraphic correlations), and thereby can reduce hydrocarbon exploration risk. As such, the number of proprietary, industry-related and public research provenance studies has increased considerably in recent years, and the development and use of new analytical techniques has also caused a surge in the number of grains, isotopes and chemical elements analysed in each study. As a result, it is today close to impossible for the individual researcher or petroleum geologist to draw on all existing provenance data. And the vast expansion of data availability demands new and better methods to analyse and visualise large amounts of data in a systematic way To this end, the Geological Survey of Denmark and Greenland (GEUS) and the Norwegian Petroleum Directorate (NPD) have established a web-based database of provenance data for the North Atlantic area: the North Atlantic Provenance Database. Construction of the database was funded jointly by GEUS and NPD. Future maintenance and further development will be funded by the petroleum industry by subscription to the database. Here, we provide a brief introduction to the database and its future development and expansion. We highlight the current capabilities with an example from East Greenland.&nbsp

The hydrology and preservation condition in the flat topped burial mound Klangshøj at Vennebjerg in Vendsyssel

Klangshøj is a flat-topped burial mound similar to the Royal Jelling mounds, although smaller.The myths tell that a well has existed on top of the mound as at Jelling and a spring had flown atthe base of the mound. In order to verify the myths and a similar hydrology in Klangshøj as foundin Jelling, several borings have been carried out in a north-south line across the mound.The investigation showed that Klangshøj is built of sods mainly harvested from heathland. Thesods are of different grain sizes from fine sand to clay. The preservation conditions were excellentin three of the six borings, where undecomposed plant remnants, occasionally greenish, wereobserved. A 14C-dating showed that the mound was built in the Viking Age. The hydrology inKlangshøj is the same as in the Jelling mounds, with a permeable bioturbation zone coveringalmost impermeable, distinct sod layers. This form a perched groundwater table in the transitionzone, which keeps the distinct sod layer below anaerobic, i.e. the preservation conditionsextremely favourable. The perched water table drains internally as in the Jelling mounds, andthere are no current nor fossil evidence to suggest a spring was ever present at the foot slope, asthe local legend suggests. Moreover, it seems unlikely that a well, similar to the one on the Jellingmound, has existed on the top of the north-facing slope, as the amount of water the well wouldhave been able to collect is little

The role of large wild animals in climate change mitigation and adaptation

Two major environmental challenges of our time are responding to climate change and reversing biodiversity decline. Interventions that simultaneously tackle both challenges are highly desirable. To date, most studies aiming to find synergistic interventions for these two challenges have focused on protecting or restoring vegetation and soils but overlooked how conservation or restoration of large wild animals might influence the climate mitigation and adaptation potential of ecosystems. However, interactions between large animal conservation and climate change goals may not always be positive. Here, we review wildlife conservation and climate change mitigation in terrestrial and marine ecosystems. We elucidate general principles about the biome types where, and mechanisms by which, positive synergies and negative trade-offs between wildlife conservation and climate change mitigation are likely. We find that large animals have the greatest potential to facilitate climate change mitigation at a global scale via three mechanisms: changes in fire regime, especially in previously low-flammability biomes with a new or intensifying fire regime, such as mesic grasslands or warm temperate woodlands; changes in terrestrial albedo, particularly where there is potential to shift from closed canopy to open canopy systems at higher latitudes; and increases in vegetation and soil carbon stocks, especially through a shift towards below-ground carbon pools in temperate, tropical and sub-tropical grassland ecosystems. Large animals also contribute to ecosystem adaptation to climate change by promoting complexity of trophic webs, increasing habitat heterogeneity, enhancing plant dispersal, increasing resistance to abrupt ecosystem change and through microclimate modification

Temporal patterns in ecosystem services research : A review and three recommendations

Temporal aspects of ecosystem services have gained surprisingly little attention given that ecosystem service flows are not static but change over time. We present the first systematic review to describe and establish how studies have assessed temporal patterns in supply and demand of ecosystem services. 295 studies, 2% of all studies engaging with the ecosystem service concept, considered changes in ecosystem services over time. Changes were mainly characterised as monotonic and linear (81%), rather than non-linear or through system shocks. Further, a lack of focus of changing ecosystem service demand (rather than supply) hampers our understanding of the temporal patterns of ecosystem services provision and use. Future studies on changes in ecosystem services over time should (1) more explicitly study temporal patterns, (2) analyse trade-offs and synergies between services over time, and (3) integrate changes in supply and demand and involve and empower stakeholders in temporal ecosystem services research