1995 - Paris Sud Minute.rar

1995 - Paris Sud Minute.rar

CLICK HERE >>> https://bltlly.com/2td6oD

plentiful, and humic acids were rarely encountered. This reference profile is quite similar to several soil profiles found at the hotspot. Although the hotspot is less than 0.1 m deep, the soil is up to 15 cm deep. The soil type was interpreted as a ferrallitic lithic-red soil. The soil at the stable site was similar to the one at the hotspot, but the humus layer was more abundant and less ferruginous. Humic acids were encountered and therefore the soil at the stable site was characterized as a black potassic-carbonated or Ferruginous-Kali-carbonated organic soil. A similar soil type was reported in France by Legros [50] and Baize and Girard [31]. This soil composition appeared to be the most organic and ferruginous among all the soils in the hotspot. It was also very similar to soils found close to slopes on the highlands of the Atlas. Due to the similarity between these two sites, we consider the soils present at the hotspot as formed in situ.

Measuring the angle of repose of the soil from the hotspot, stable and reference sites, we established that the soil was more inclined at the hotspot comparatively to the other sites (Figure 3).

The hardest soil in the hotspot was always taken as reference, since on a rock outcrop is unlikely to find soil with a more basaltic component that hardens as a consequence of aging and is found especially at the periphery of the hotspot. The most plant-available humus was often taken as reference to establish the soil types for the hotspot, although it was the most irregular soil (rocky soil with a depth from 2 to 10 cm) because often there were many mineral coloured spots.

In a first time, we drilled the three sites. A great number of soil cores were collected from each site. We began by describing intermittently the zones of the hotspot, the stable site and the third reference site by soil colouration. We divided material in four main zones: woody plant roots, litter, humic acids and mineral soil (see Figure 4). d2c66b5586