Hydrological soil behavior in areas with semi-arid vegetation (Beni Chougrane Mountains, Algeria)

In northern Algeria, the physical degradation of land by water erosion is one of the most serious forms of degradation. As is well known, vegetation plays an important role against water erosion. In the mentioned area the potential vegetation called maquis is currently characterized by an advanced stated of degradation, often ranging between sparse cover and bare soil. In the Oued Fergoug watershed belonging to the Beni Chougrane Mountains (NW of Algeria), a trial was carried out with a mini rainfall simulator designed by ORSTOM to evaluate the runoff rate and the sediment load at experimental plot scale and in a situation of bare soil. The experimental layout took into account two different surface slopes, three different rainfall intensities, and three levels of initial soil water content. The highest runoff values observed exceeded 0.50 mm min

A new species of Cyperus L. (Cyperaceae) from northeastern Brazil

A new species, Cyperus potiguar, is here described and illustrated. It is a perennial species morphologically related to C. alvesii and C. ligularis, but can be recognized by spikelet size, number and size of glumes, and length of rachilla internodes. It is found in the semi-arid vegetation of northeastern Brazil, locally called Caatinga.