Soils of the Jurassic formations in the central Algarve; their occurrence, distribution, genesis and site qualities

In the central Algarve different soils have developed dependent on petrography of the parent material, slope position and recent erosion. The general patterns of occurence and distribution of different soils are described. The age of an eutric Nitosol is estimated and the relation between the soil and the parent material is investigated. Some different soils are described as examples with their chemical and physical properties. The water budget of soils is described in general with considerations concerning ground water recharge and run-off as well as in dependence of climate and of different site conditions

Handbuch der Bodenlehre - Ein Werk von Edwin Blanck

In den Jahren 1929 – 1932 entstand das erste Handbuch der Bodenkunde überhaupt und in deutscher Sprache. Das war kurz nach der Gründung der internationalen und deutschen Bodenkundlichen Gesellschaften. Bis heute muß dieses Werk als ein Jahrhundertwerk gefeiert werden. Edwin Blanck , Jahrgang 1877, hat Naturwissenschaften studiert und 1901 in Heidelberg über Kolloide promoviert. Nach verschiedenen Tätigkeiten in landw. Versuchstationen wurde er 1918 in Tetschen – Liebwerd (Böhmen) Ordinarius. Bereits 1921 wechselte er nach Göttingen, wo er Wissenschaftsgeschichte schrieb. Er war Herausgeber der „CHEMIE der ERDE“, des „Journals für Landwirtschaft“ und schließlich auch der PuB. Außer dem Handbuch.. verfaßte er ein Lehrbuch der Agrikulturchemie und eine Einführung in die genetische Bodenlehre. Giesecke, Scheffer und Lemmermann haben unter anderen Würdigungen dieses herausragenden Bodenkundlers verfaßt. !950 bis zu seinem Tode 1953 wurde er noch Präsident der DBG

WRB- Klassifizierung von Tonverlagerungsböden im Gelände mittels Gammastrahlungssignaturen in Nordthailand

Die Tonverlagerung ist der wichtigste bodenbildende Prozess in Nordthailand (Schuler 2008). In Abhängigkeit von Petrographie, Topographie und Klima kommt es im Wesentlichen zur Bildung von Acrisolen und Alisolen, untergeordnet treten daneben auch Luvsiole und Lixisole auf. Entsprechend der WRB 2006 Klassifikation (World Reference Base for Soil Resources IUSS Working Group WRB 2006) lassen sich diese Referenzbodengruppen nur anhand der Kationenaustauschkapazität des Tons und der Basensättigung voneinander unterscheiden. Der erste Parameter lässt sich jedoch nur durch zeitraubende und kostenintensive Analysen bestimmen, was für Bodenkartierer unbefriedigend ist, da diese Information schon im Feld sehr hilfreich sein kann. Das Ziel dieser Arbeit besteht darin, herauszufinden, ob sich Tonverlagerungsböden anhand ihrer Gammastrahlungssignaturen bereits im Feld voneinander unterscheiden lassen. Zugrunde liegt hier die Annahme, dass unterschiedliche Tonverlagerungsböden eine spezifische Tonmineralzusammensetzung aufweisen, welche sich in der Geochemie und folglich in der Gammastrahlungssignatur widerspiegelt. Sowohl die bodenbasierte als auch die luftgestützte Messung der Gammastrahlung von Ton-verlagerungsböden über Kalkstein ergab höchst signifikant unterschiedliche Strahlungssignaturen für K, eU, und eTh. Insbesondere die K- und eTh-Signaturen erlaubten eine deutliche Trennung von Acrisolen und Alisolen. Sollten sich die Messungen auch an anderen Lokalitäten und bei anderem Ausgangsgestein wiederholen lassen, dann ließen sich zukünftig mehr Tonverlagerungsböden mit einem tragbaren Strahlungsmessgerät und pH-Meter bereits im Feld voneinander unterscheiden. Zur Kartierung größerer Areale kann theoretisch eine Klassifizierung durch luftgestützte Messungen vorgenommen werden. Damit könnten enorme Analysenkosten eingespart werden

Freely-moving mice visually pursue prey using a retinal area with least optic flow

Mice have a large visual field that is constantly stabilized by vestibular ocular reflex driven eye rotations that counter head-rotations. While maintaining their extensive visual coverage is advantageous for predator detection, mice also track and capture prey using vision. However, in the freely moving animal quantifying object location in the field of view is challenging. Here, we developed a method to digitally reconstruct and quantify the visual scene of freely moving mice performing a visually based prey capture task. By isolating the visual sense and combining amouse eye optic model with the head and eye rotations, the detailed reconstruction of the digital environment and retinal features were projected onto the corneal surface for comparison, and updated throughout the behavior. By quantifying the spatial location of objects in the visual scene and their motion throughout the behavior, we show that the image of the prey is maintained within a small area, the functional focus, in the upper-temporal part of the retina. This functional focus coincides with a region of minimal optic flow in the visual field and consequently minimal motion-induced image blur during pursuit, as well as the reported high density-region of Alpha-ON sustained retinal ganglion cells

The relevance of particulate organic carbon (POC) for carbon composition in the pore water of drained and rewetted fens of the "Donauried" (South-Germany)

International audienceNumerous studies have dealt with carbon (C) concentrations in Histosols, but there are no studies quantifying the relative importance of all individual C components in pore waters. For this study, measurements were made of all the carbon components (i.e., particulate organic carbon, POC; dissolved organic carbon, DOC; dissolved inorganic carbon, DIC; dissolved methane, CH4) in the soil pore water of a calcareous fen under three different water management regimes (re-wetted, deeply and moderately drained). Pore water was collected weekly or biweekly (April 2004 to April 2006) at depths between 10 and 150 cm. The main results obtained were: (1) DIC (94?280 mg C l?1) was the main C-component. (2) POC and DOC concentrations in the pore water (14?125 mg C l?1 vs. 41?95 mg C l?1) were pari passu. (3) Dissolved CH4 was the smallest C component (0.005?0.9 mg C l?1). Interestingly, about 30% of the POM particles were colonized by microbes indicating that they are active in the internal C transfer in the soil profile ("C-Shuttles"). Consequently, it was concluded that POC is at least as important as DOC for internal soil C turnover. There is no reason to assume significant biochemical differences between POC and DOC as they only differ in size. Therefore, both POC and DOC fractions are essential components of C budgets of peatlands. Furthermore dissolved CO2 in all forms of DIC apparently is an important part of peatland C-balances

Visual pursuit behavior in mice maintains the pursued prey on the retinal region with least optic flow

Mice have a large visual field that is constantly stabilized by vestibular ocular reflex (VOR) driven eye rotations that counter head-rotations. While maintaining their extensive visual coverage is advantageous for predator detection, mice also track and capture prey using vision. However, in the freely moving animal quantifying object location in the field of view is challenging. Here, we developed a method to digitally reconstruct and quantify the visual scene of freely moving mice performing a visually based prey capture task. By isolating the visual sense and combining a mouse eye optic model with the head and eye rotations, the detailed reconstruction of the digital environment and retinal features were projected onto the corneal surface for comparison, and updated throughout the behavior. By quantifying the spatial location of objects in the visual scene and their motion throughout the behavior, we show that the prey image consistently falls within a small area of the VOR-stabilized visual field. This functional focus coincides with the region of minimal optic flow within the visual field and consequently area of minimal motion-induced image-blur, as during pursuit mice ran directly toward the prey. The functional focus lies in the upper-temporal part of the retina and coincides with the reported high density-region of Alpha-ON sustained retinal ganglion cells.Mice have a lot to keep an eye on. To survive, they need to dodge predators looming on land and from the skies, while also hunting down the small insects that are part of their diet. To do this, they are helped by their large panoramic field of vision, which stretches from behind and over their heads to below their snouts. To stabilize their gaze when they are on the prowl, mice reflexively move their eyes to counter the movement of their head: in fact, they are unable to move their eyes independently. This raises the question: what part of their large visual field of view do these rodents use when tracking a prey, and to what advantage? This is difficult to investigate, since it requires simultaneously measuring the eye and head movements of mice as they chase and capture insects. In response, Holmgren, Stahr et al. developed a new technique to record the precise eye positions, head rotations and prey location of mice hunting crickets in surroundings that were fully digitized at high resolution. Combining this information allowed the team to mathematically recreate what mice would see as they chased the insects, and to assess what part of their large visual field they were using. This revealed that, once a cricket had entered any part of the mices large field of view, the rodents shifted their head - but not their eyes - to bring the prey into both eye views, and then ran directly at it. If the insect escaped, the mice repeated that behavior. During the pursuit, the crickets position was mainly held in a small area of the mouses view that corresponds to a specialized region in the eye which is thought to help track objects. This region also allowed the least motion-induced image blur when the animals were running forward. The approach developed by Holmgren, Stahr et al. gives a direct insight into what animals see when they hunt, and how this constantly changing view ties to what happens in the eyes. This method could be applied to other species, ushering in a new wave of tools to explore what freely moving animals see, and the relationship between behaviour and neural circuitry