Evaluation of forest grazing as a management practice to utilize and control Miscanthus sinensis in a young tree plantation in southern Kyushu, Japan

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.

Deposition and decomposition of cattle dung in forest grazing in southern Kyushu, Japan

“…The increased DM concentration of feces with the progression of the grazing season may reflect decreased moisture contents of forage. Browsing by the animals of woody plants (e.g., Eurya japonica, Mallotus japonicas; Hirata et al 2007b) rich in digestiondeterring chemicals [e.g., tannins (Chowdappa 2006), lignins; as a defense mechanism against herbivory; Scholes and Walker (1993)] may produce decomposition-resistant feces. The tree plantation used in the present study had no previous grazing history prior to this grazing trial and was never adjacent to grazed grassland, and is likely to have very limited populations of major dung-decomposing animals.…”

“…Nogami et al (1993) recorded 176 species (71 families) of herbaceous species (grasses, sedges, forbs), lianas, shrubs, trees and ferns as weeds in the young plantations on the study site. M. sinensis, the most preferred species by grazing cattle (Hirata et al 2007b), was distributed throughout the three paddocks as the most dominant herbaceous species.…”

“…A grazing trial with beef cattle commenced in 1996 in a young Chamaecyparis obtusa (an evergreen conifer) plantation in southwestern Japan to evaluate the forestlivestock combination as a land-use option in the region (Hirata et al 2007b). Grazing by cattle rapidly degraded vegetation structure and productivity of the major weed grass Miscanthus sinensis (Hirata et al 2007a, b).…”

Aboveground plant mass and mass available to grazing goats in a mountainous shrubland in subtropical China

“…If farmers intend to continue grazing practices in such areas, it is necessary to develop animal husbandry well matched to the recovery and maintenance of forests and the local mountainous environment (Johnson et al. 1986; Pell 1999; Hirata et al. 2007).…”

“…The main forest policy to shrubs and poor forests by the local administration is afforestation, but not livestock production in forests (Hsiung et al 1995;Zhou and Chokkalingam 2006). If farmers intend to continue grazing practices in such areas, it is necessary to develop animal husbandry well matched to the recovery and maintenance of forests and the local mountainous environment (Johnson et al 1986;Pell 1999;Hirata et al 2007). It is also necessary to change primitive stock raising methods to modern stock management styles to improve farmers' livelihood.…”