ANNUAL REGROWTH AND EDIBLE BIOMASS OF 2 SPECIES OF ATRIPLEX AND OF CASSIA-STURTII AFTER BROWSING

Atriplex nummularia, Atriplex canescens and Cassia sturtii were plante d in the northern Negev in 1984 in six replicates at five planting den sities: 625, 1111, 2500, 4444 and 10,000 shrubs ha(-1). They were left undisturbed for 3 years until July 1987, following which they were su mmer browsed by sheep and goats until the shrubs were completely defol iated, and summer browsed again 1988, 1990 and 1991. A. nummularia was superior to the other species. It had the highest total and edible bi omass after 3 years of undisturbed growth and the best absolute recove ry after browsing. Neither of the Atriplex species recovered the initi al standing biomass recorded before browsing in 1987, and there was a serious decline in the regrowth of leaf biomass. Cassia sturtii recove red its initial standing biomass at the two highest planting densities but failed to do so at the other densities.