Bodenkundliche Detailkartierung erosionsgefaehrdeter Standorte in Nordrhein-Westfalen und Ueberpruefung der Bodenerodierbarkeit (K-Faktor)

The reliable estimation of the danger of erosion for plough-lands with the help of the general soil erosion equation requires an adaptation of the system of equations to the respective climatic conditions. It is tested, whether this equation can be applied to the climatic region Northrhine-Westfalia which is influenced by the Atlantic Ocean. The study focussed on the spatially specific factors R and K of the erosion equation. Eight locations were selected covering as broad a spectrum as possible of plough-lands endangered by erosion in Northrhine-Westfalia. Detailed mappings of the investigated plough-lands and chemical and physical investigations of soil profiles yielded informations about already occurred soil erosion and the parameters of actual soil erosion. (orig./MZ)SIGLEAvailable from TIB Hannover: RO 3338(16) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

In Situ Detection of Tree Root Systems under Heterogeneous Anthropogenic Soil Conditions Using Ground Penetrating Radar

Tree roots can cause damage to surface and subsurface infrastructure. Hence, timely detection of root system architecture (RSA) is needed to reduce conflict between trees and man-made facilities. Because excavation is expensive and often restricted, noninvasive detection of RSA by ground penetrating radar (GPR) is a promising technique. Although several studies have proven the ability of GPR for RSA detection, the problem of distinguishing roots from unwanted reflections at urban test sites with heterogeneous, silty, clayey, or stony soil has not yet been fully solved. This study assessed the performance of GPR for in situ detection of RSA from a plane tree (Platanus acerifolia) and a buckeye (Aesculus hippocastanum) in urban heterogeneous multilayered soil using shielded 250-MHz antennas. Repeated manual hyperbola selections were performed, extracting the three-dimensional (3D) coordinates, which were visualized in top view to reveal connected structures. Unwanted selections were manually filtered by internal confirmation using depth slices from 3D radargram interpolations. Root indications were retraced in the field and validated by vacuum excavation. At our test site, the suggested approach was suitable for detecting the lateral positions of roots with diameters between 1 and 4 cm at depths of 17 to 70 cm, despite unfavorable substrate. Moreover, the assumed depth ranges were correct for both trees, and the main depth characteristics were fairly precisely projected. The rapid and cost-effective protocol allows minimal interventions and opens the door for similar applications in urban and nonurban land uses

Relações solo-paisagem em uma topossequência sobre substrato granítico em Santo Antônio do Matupi, Manicoré (AM)

Considerando as dimensões da região amazônica e a necessidade de estudos que estabeleçam conexões entre os solos e a expressão da paisagem, o objetivo deste trabalho foi estudar as relações solo-paisagem em uma topossequência sobre substrato granítico em Santo Antônio do Matupi, Manicoré, AM. Foi estabelecido um caminhamento de 3.000 m a partir do "espigão" da vertente, no seu sentido mais suave, com identificação dos segmentos da vertente com base na "quebra" do declive do terreno. Foram abertas trincheiras nos segmentos de vertente mapeados, e perfis foram caracterizados morfologicamente, coletando-se amostras de seus horizontes. Foram realizadas análises físicas (textura, ADA e GF, Ds e Dp, Pt e CHSS), químicas (pH em água e KCl, Ca, Mg, K, Na e Al trocáveis, P disponível, H + Al e C orgânico; SiO2, Al2O3 e Fe2O3 (método do H2SO4) e óxidos de Fe "livres" extraído com ditionito-citrato-bicarbonato e o Fe mal cristalizado extraído com oxalato de amônio) e mineralógicas (frações areia, silte e argila), usando difratometria de raios X. As variações do relevo favoreceram a presença de solos distróficos nos topos e solos eutróficos no sopé de transporte. As variáveis ΔpH, relação silte/argila, V % e relação Fed/Fet indicaram a presença de solos mais intemperizados nas áreas de topo da paisagem e solos com menor grau de evolução na encosta e no sopé de transporte. A composição mineralógica da fração argila mostrou-se relativamente homogênea, com predominância de caulinita e gibbsita e menor proporção de mica e quartzo