Effects of simulated browsing on the growth of Austrocedrus chilensis saplings

Abstract

In the forests of Austrocedrus chilensis (D.Don) Florin et Boutleje (Cupressaceae) it is frequent to observe numerous mutilated and dwarfed saplings which have been browsed by domestic cattle and exotic deer. One way to assess the effects of browsing on plant growth is by simulating this process through defoliation. This study includes results from four years of artificial browsing at different intensities on A. chilensissaplings. Our objective was to evaluate the possible compensatory growth by A. chilensis. To that end we measured the effects of simulated browsing on the growth of saplings kept under two different experimental conditions, with and without water stress. Treatments were applied at the end of winter of 1993 and were repeated on 1994, 1995 and 1996. Treatments consisted in pruning and cutting. Neither cutting effects nor factors interactions were found. Pruning resulted in a reduction of saplings biomass of 44% and was only significant at the more intensive level. Watering produced saplings with five times more biomass, but the general response of A. chilensis to simulated browsing was the lack of compensation regardless the intensity of pruning or the quality of site.