This study monitored deposition and decomposition of cattle dung in a grazed young Chamaecyparis obtusa (an evergreen conifer) plantation in southwestern Japan, as a part of exploring the impacts of livestock in the forest grazing system. Animals defecated 10-19 times hd À1 day À1 , producing feces of 2.2-3.5 kg DM and 33-73 g N per animal per day. The DM and N concentrations of feces ranged from 157-207 g DM kg À1 and 14.8À23.1 g (kg DM) À1 , respectively. Occurrence of defecation was spatially heterogeneous, with feces being concentrated mainly on areas for resting (forest roads, ridges and valleys) and moving (forest roads and along fence lines). Decomposition of dung pats was considerably slow, showing the rates of 1.37-3.05 mg DM (g DM) À1 day À1 as DM loss. Decomposition was further slower on the basis of N release, 0.51-1.63 mg N (g N) À1 day À1 , resulting in steadily increased N concentrations of dung pats with time after deposition. The results show that introduction of livestock into a forest (i.e., forest grazing) may limit nutrient availability to plants, by redistributing nutrients into areas with no vegetation (bare land and streams) and by establishing a large N pool as feces due to an imbalance between deposition and slow release, though further studies are necessary for investigating the occurrence of slow dung decomposition in other forest situations.