抄録
Suitability for cattle-grazing forestry system in Morotsuka Village, Miyazaki, southern Japan, was examined in terms of reducing the physical damages to young planted timber trees and conserving surface soil based on topographic analyses. For the first step of analyses, suitability for timber production were estimated for grids (28.5m × 28.5 m) by companng the site productivity and site stability (inversely, probability of natural disasters) calculated from topographic parameters using a digital elevation model As the results, 'Suitable site', 'Semi-suitable site' and 'Unsuitable site' occupied 36%, 49% and 15% of the whole village area, respectively. For the second step, suitability for cattle-grazing in young plantation forests was categorized by criteria of slope inclination and slope convexity into four categories : 'Suitable' (16%), 'Semi-suitable' (21%), 'Less-suitable' (21%), and 'Unsuitable' (48%). Among the sites which were suitable for timber production, 'Suitable' site for cattle-grazing occupied 30%, indicating a need of attention for concerning conservation of soil and planted trees even in the better plantations sites for timber production. 'Semi-suitable' sites for timber production were mostly designated as 'Less-suitable' or 'Unsuitable' for cattle-grazing. The sites selected as 'Suitable' or 'Semi-suitable' for cattle-grazing were located on slope crests in terms of micro-topographic classification, suggesting these sites likely to be correspond to those had formally been utilized meadows or agro-forestry in the past.
