Particle Swarm Optimization for Woody Vegetation Assessment in a Semi-Arid Savannah Ecosystem

In many ways, the surface of the planet Mars is similar to that of Earth. However, Mars's lower gravity has an effect on the settling and transport of sediment particles moving in water. Using specific experimental equipment to measure settling velocity aboard a parabolic flight, it was possible to observe how sediments settled in Martian gravity. These experiments served to illustrate that parabolic flights can be used as analogue environments for surface processes on Mars.

Soil quality depends on water availability for plants. Sandy soils with a poorly permeable layer (fragipan) are considered inept for agriculture. However they are cultivated in Namibia as they secure a minimum harvest during droughts. In order to understand the hydrological influence of fragipans in these soils, soil moisture content was measured. The results illustrate that the combination of sandy topsoil and shallow fragipan has beneficial effects on plant-available water during dry periods.

Soil erosion by wind and water is a commonly recognized phenomenon on agricultural land. Erosion in forests is studied less and generally considered to be limited because of the soil protection by vegetation. However, trees, when toppled because of old age or wind, loosen a considerable amount of soil when their roots are pulled from the ground. In addition, the holes left in the ground act as collectors for water and concentrated runoff, causing significant soil loss on forested slopes.