EROSIÓN HÍDRICA EN ANDOSOLES DE LAS ISLAS CANARIAS

A. RODRÍGUEZ RODRÍGUEZ, C.D. ARBELO, J.A. GUERRA, J.L. MORA

Dpto. Edafología y Geología, Facultad de Biología,Universidad de La Laguna, Avda.
Astrofísico Francisco Sánchez s/n, 38204, La Laguna, Tenerife (Islas Canarias).

Abstract

This paper shows the results of water erosion rate measurements in andosols, through a continued 9-year field experiment in three experimental plots (25 x 8 m) representing bare soil, planted pine forest and shrub. The highest runoff and erosion rates have been registered in the bare soil plot, although they are not clearly related to the rainfall intensity or soil erodibility, estimated by conventional methods. Sediment analysis shows that erosion processes in these soils affect mainly the microgranular and crumb aggregates, which are mobilized with no previous dispersion, thus suggesting that the hydrophobicity of organic surface horizons in these soils, as well as their high moisture retention capacity and infiltration rates, once they are wet, are the properties that determine in the highest degree the runoff and sediment yield in these soils, in these conditions.

Key words: Andosols, Water erosion, Experimental plots, Runoff, Canary Islands.