Erosional response of recently installed forest areas: effects of site-preparation techniques

Abstract

Forests provide the most effective vegetation cover for erosion control and it is in forested areas that lowest soil loss rates are recorded (Hudson, 1981; Zachar, 1982). However, in cultivated forests, the stand installation and early tree growth stages are most critical, because, normally, vegetation has not yet attained a sufficiently effective cover (Dissmeyer, Foster, 1984; Lucci et al., 1994). Actually, young forest stands were identified as areas of accelerated erosion in NE Portugal (Agroconsultores e Coba, 1991). Site-preparation techniques may play, then, a major role in mitigating risks, because they are intended to improve soil conditions for plant growth and to reduce erosion (Alves, 1988). In order to compare their effectiveness for erosion control, several customary site-preparation techniques in NE Portugal were applied prior to installing a mixed stand (Pseudotsuga mensiezii and Castanea sativa), and thereafter runoff and soil loss were monitored. This paper aims at presenting and discussing, in a preliminary approach, results of the first two years after site-preparation.