The effect of resource depletion on the feeding behaviour of a browser: winter foraging by moose on Scots pine.
The foraging dynamics of the moose (Alces alces) were studied in trials near Umeå, Sweden in winter 1988-89 in the following artificial stands set up in a forest area: large (stems) Pinus sylvestris + Populus tremula; large P. sylvestris + small P. sylvestris; large P. sylvestris + Alnus incana. Special attention was paid to the analysis of the pattern of P. sylvestris exploitation because of the tree's commercial value. Moose browsing was assessed by counting bites and measuring bite diam. Initially, the total consumption of twig biomass in the P. sylvestris + P. tremula stand was twice as high as in the small + large P. sylvestris and P. sylvestris + A. incana stands. This difference remained until almost half the available biomass in the P. sylvestris + P. tremula stand had been consumed. Within stands, preference for P. tremula over P. sylvestris increased over time but preference for P. sylvestris over A. incana decreased. Bite diam. on P. sylvestris decreased over time. Browsing on P. sylvestris was only slightly affected by species composition of tree mixtures. Browsing intensity on individual P. sylvestris trees was positively correlated with the amounts consumed on adjacent stems.