Henrik Breuning-Madsen

Meta‐barcoding of ‘dirt’ DNA from soil reflects vertebrate biodiversity

DNA molecules originating from animals and plants can be retrieved directly from sediments and have been used for reconstructing both contemporary and past ecosystems. However, the extent to which such ‘dirt’ DNA reflects taxonomic richness and structural diversity remains contentious. Here, we couple second generation high‐throughput sequencing with 16S mitochondrial DNA (mtDNA) meta‐barcoding, to explore the accuracy and sensitivity of ‘dirt’ DNA as an indicator of vertebrate diversity, from soil sampled at safari parks, zoological gardens and farms with known species compositions. PCR amplification was successful in the full pH range of the investigated soils (6.2 ± 0.2 to 8.3 ± 0.2), but inhibition was detected in extracts from soil of high organic content. DNA movement (leaching) through strata was evident in some sporadic cases and is influenced by soil texture and structure. We find that DNA from the soil surface reflects overall taxonomic richness and relative biomass of individual species. However, one species that was recently introduced was not detected. Furthermore, animal behaviour was shown to influence DNA deposition rates. The approach potentially provides a quick methodological alternative to classical ecological surveys of biodiversity, and most reliable results are obtained with spatial sample replicates, while relative amounts of soil processed per site is of less importance.

Soil Atlas of Africa

of water, nutrients and as a medium for growing. Soil stores, filters, buffers and transforms substances that are introduced into the environment. This capability is crucial in producing and protecting water supplies and for regulating greenhouse gases. Soil is a provider of raw materials. Soil is also an incredible habitat and gene pool. Soil is a fundamental component of our landscape and cultural heritage. The properties of soil vary tremendously from region to region. Soils under tropical rainforests are vulnerable to erosion and nutrient depletion if the vegetation cover is removed. Oasis regions in deserts and the Sahel show how seemingly infertile soils can be cultivated in the presence of water. The wetlands of Congo and other major African systems are stores of soil organic carbon and important wildlife habitats. The black, clay-rich soils of the Nile Valley in Sudan are rich in nutrients but difficult to cultivate when very wet or very dry. Soils with high salt levels are not suitable for the cultivation of crops but may support a unique plant community. AFRICA SOIL ATLAS OF

Generating a Danish raster-based topsoil property map combining choropleth maps and point information.

Abstract Geografisk Tidsskrift, Danish Journal of Geography 107(2):1–12, 2007 The Danish environmental authorities have posed a soil type dependent restriction on the application of nitrogen. The official Danish soil map is a choropleth topsoil map classifying the agricultural land into eight classes. The use of the soil map has shown that the maps have serious classification flaws. The objective of this work is to compile a continuous national topsoil texture map to replace the old topsoil map. Approximately 45,000 point samples were interpolated using ordinary kriging in 250 m x 250 m cells. To reduce variability and to obtain more homogeneous strata, the samples were stratified according to landscape types. Five new soil texture maps were compiled; one for each of the five textural classes, and a new categorical soil type map was compiled using the old classification system. Both the old choropleth map and the new continuous soil maps were compared to 354 independent soil samples. 48% of the 354 independent samples fell into the correct class in the old map; in the new map 60% fell into the correct class, which is a significant improvement. The verification also showed that 62% of the samples in the forest areas were correctly classified, although these areas were not classified in the old map. Furthermore, when both the old and the new map were compared cell-by-cell, 74% of the cells were classified as belonging to the same class. The new textural maps were tested against the textural properties of 631 independent samples, and the root mean squared error (RMSE) of this comparison was calculated and found to be in the range of 2.8 to 5.2.

Mineralogy of dust deposited during the Harmattan season in Ghana

Abstract In Ghana, a dust-laden Harmattan wind blows from the Sahara in the period November to March. Some of the dust is trapped in the vegetation, in lakes and other inland waters, and a little on the bare land, whereas the rest of the dust is blown further away to the Ivory Coast or out into the Atlantic Ocean. In this project, we studied samples of dust and topsoils in various agroecological zones, from the north to the south of Ghana, focussing mainly on the mineralogy of these materials. Some data about grain sizes and morphology of the samples are also presented. Feldspars, together with quartz, are the common minerals found in Harmattan dust, but the relative contents of K-feldspars and plagioclase vary markedly in the different zones. This variation is consistent with changes in the relative content of the feldspars in the topsoil, indicating a substantial local contribution to the Harmattan dust. This conclusion is supported by the clay mineralogy of the samples. However, the pH of the dust is significantly higher than that of the local soils, indicating that a substantial amount of the dust comes from the Sahara.

Comparison of the composition of iron pans in Danish burial mounds with bog iron and spodic material

Abstract Excavations of Danish burial mounds dated to the South Scandinavian Early Bronze Age (1700–1000 BC) occasionally show thin iron pans encapsulating the interior of the mounds. When strongly cemented these pans can be classified as placic horizons. The encapsulated core was often wet and anaerobic and in Jutland well-preserved oaken log coffins with remnants of organic artefacts and human beings were discovered. Various theories for the development of these pans have been proposed. The chemical composition of the cement of two iron pans in burial mounds is compared with that from a bog iron deposit and a spodic horizon. This shows that the cement from the iron pans is similar to that in bog iron and not to the spodic material.

Soil Profile Analytical Database for the European Union

Danish Journal of Geography 95: 49–58, 1995. In 1985 the European Communities now the European Union published a soil map covering all the Community countries. This map has been digitized, but for modelling purposes it was necessary to compile a Soil Profile Analytical Database connected to the European Communities Soil Map. This compilation commenced in 1992 following a decade of expert group meetings concerning European soil and land data. This account describes the events that led to the decision to develop this database, and how it was compiled.

Influence of perennial colonies of piscivorous birds on soil nutrient contents in a temperate humid climate

Abstract Geografisk Tidsskrift—Danish Journal of Geography 110(1):25–35, 2010 During the last decades, the number of perennial colonies of piscivorous birds especially cormorant colonies in North-western Europe has grown rapidly due to protection. Their impact on vegetation has been recognized, as many trees containing perennial colonies of piscivorous birds have collapsed, but the birds influence on the soil conditions has only in few cases been studied in detail. In this study the influence of perennial colonies of piscivorous birds on soil nutrient contents and accumulation of carbon, nitrogen and phosphorus in a humid climate has been determined by measuring pH, electric conductivity and content of carbon, nitrogen, phosphorus, calcium and potassium in a reference area and in two cormorant sub-colonies. In general, the soils exposed to cormorant guano had lower pH and higher contents of plant available phosphorus, calcium and potassium compared to the control reference soil, especially in the top horizons, and the magnitude of increase in nutrient content varied with the bird-dropping density and the age of the colony. In addition, soil influenced by cormorants had a higher electric conductivity compared to the control reference and can be classified as saline soils. Under influence of the cormorants the herb vegetation below the nesting areas has been changed.

The Role of Termites in Soil Formation in the Tropical Semi-Deciduous Forest Zone, Ghana

Abstract Soil Macrofauna especially insects have been recognized as being an important factor in regulating soil processes and thereby the soil profde development. The influence of earthworms is well documented and it is the dominant member of the soil macrofauna influencing the soil formation processes in the temperate zone. In the tropics, termites and ants play the major role in the nutrient recycling and the movement and transportation of soil material. This paper describes the influence of termites on the soil formation in the tropical wet semi-deciduous forest in Ghana at the north coast of the Gulf of Guinea. The termites form distinct soil horizons especially at the summits of the landscapes where gravel free soil horizons are formed upon gravel rich horizons, and in some cases soil heaps are formed after the decomposition of huge trees.

The South Scandinavian barrows with well-preserved oak-log coffins

Recent archaeological and pedological research on South Scandinavian Bronze Age barrows reveals that the remarkable conditions of preservation in a number of mounds are the result of particular construction techniques or special activities during construction. Augerings indicate that the phenomenon is concentrated within specific groups of barrows with central positions in a hypothetical Bronze Age communication system.

Soil map of Denmark According to the Revised FAO Legend 1990

Abstract Danish Journal of Geography 96: 51–59, 1996. In the first half of the 1990s, a comprehensive EU soil database was established comprising the EU soil map from 1985 published at scale 1:1.000.000, soil attributes and a soil analytical database. The EU soil map was based on a slightly revised FAO 1974 legend. In 1990 FAO published a revised legend to Soil Map of the World, and based on this system Central and Eastern Europe are now constructing soil maps at scale 1:1.000.000. In order to harmonize these soil maps, an updating of the EU soil map is necessary according to the FAO 1990 legend. The present paper describes the updating of the Danish part of the EU soil map.