THE CHARACTERISTICS AND UTILIZATION OF SHRUB-GRASSLANDS IN TROPICAL AND SUBTROPICAL MOUNTAINS OF YUNNAN
云南热带、亚热带山地灌草丛植被特点及利用途径

Shrub-grasslands are widely distributed in tropical and subtropical mountains of Yunnan. This vegetation type consists mainly of tropical grass species (or originated from tropics), which make a very distint grass-layer, and above that a few shrubs and trees scattered. A classification system of these shrub-grasslands has already made to show that 5 vegetation-subtypes, 12 formations and 17 associations have been found now. The 5 vegetation-subtypes are hot shrub-grassland; dry-hot shrub-grassland; warm-hot shrub-grassland; warm-temperate shrub-grassland; temperate-cool shrub-grassland, among which, the dry-hot one may be recognized as semi-savanna or secondary savanna. In the long course of succession, the 5 vegetation-subtypes developed into 5 climax vegetations respectively, that is the tropical monsoon forest or tropical rain forest; river valley monsoon forest or monsoonal evergreen-deciduous mixed forest; monsoonal evergreen broad-leaved forest (through Pinus kesiya var. langbianensis forest); semihumid evergreen broad-leaved forest (through Pinus yunnanensis forest); mountainous humid evergreen broadleaved forest (through Pinus armandi forest or P. yunnanensis forest). In utilization and exploitation, it is important to bear in mind that where slope is over 20 degrees, forestry must be developed, and where it is under 20 degrees, animal husbandry and other plantations should be carried out. Areas or points already designated as reserves must be protected and many important scientific researches must also be conducted.