No abstract

Miscanthus sinensis, a tall cespitose warm‐season perennial grass, occurs widely in tree plantations across Japan as a major weed. A 4‐year grazing trial was conducted in a young Chamaecyparis obtusa (an evergreen conifer) plantation in south‐western Japan, in an effort to evaluate forest grazing as a management practice to utilize and control M. sinensis and to deepen a mechanistic understanding of the responses of this grass to herbivory. The plantation was continuously stocked by Japanese Black cattle during the grazing season from May–November (July–November in the first year) at rates of 0.38–0.63 animals ha−1. M. sinensis was always the major species selected by animals, with most of the plants (80–90%) in the paddocks being defoliated during the grazing season. Reflecting these, M. sinensis plants declined with time under grazing, mainly in shoot number per tuft and partly in leaf appearance rate and the weight of the youngest fully expanded leaf, leading to a drastic decrease in production of leaves (laminae) as a photosynthetic organ and a main feed component for animals. Animals did little fatal damage to C. obtusa trees. Performance of animals was acceptable for cows that had experienced forest grazing in preceding years, but needed improvement for inexperienced heifers and calves. The results demonstrate the potential value of cattle grazing in utilizing and controlling M. sinensis in young tree plantations, which enables multifunctional land use linking forest and animal industries. Further studies are necessary to explore the optimum grazing intensity that balances effective control and extended utilization of the grass.

No abstract

This 4-year study monitored maintenance behavior of beef cattle (Japanese Black) foraging in a young Chamaecyparis obtusa (an evergreen conifer) plantation in southwestern Japan. The animals spent 551 ± 8 min (mean ± SE) per day grazing, 436 ± 4 min ruminating, 313 ± 9 min resting, 44 ± 2 min moving, and 96 ± 4 min on other activities.

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.