广西亚热带酸性土丘陵山地草丛的群落学特点及其合理利用的方向

我国亚热带酸性土丘陵山地,当常绿阔叶林或山地常绿、落叶阔叶混交林被采伐以后,在采伐迹地上遭火烧的情况下,无论垦殖与否,都会出现大片的以禾本科草类或蕨类植物占优势的草丛。如果连年都遭受火烧,它就能保持稳定,成为所谓的火烧顶极。一旦火烧停止,阳性乔灌木树种就会迅速侵入,几年之后就会发展成为灌丛,并向森林的方向发展。热带许多地方的情况也是这样。毫无疑问,亚热带草丛是亚热带

PHYTOCOENOLOGICAL FEATURES OF SUBTROPICAL GRASS-HEATH ON ACID SOIL MOUNTAIN IN GUANGXI AND ITS RATIONAL UTILIZATION

The subtropical grass-heath is formed after evergreen broad-leaf forest and mountain mixed evergreen and deciduous broad-leaf forestare cut. It is quite evident that this grass-heath is a successive stage in the developmental process of subtropical forest. Analysis of its phytocoenological features shows that its physiognomy is characterized by herbaceous, simple-leaved, microphyllous type of winter withered hemicryptophytcs with erect stem, Phanerophytes also occupy certain proportion, especially with much deciduous broad-leaf nanophanerophytes. As for the structure of the community, in the general, there is only one layer, namely the herbaceous layer,But synusia structure is also considerably complex, having different kinds of herbs and shrubs. Floristic compositions of the community is dominated by East Asia elements and endemic subtropical plant species, among which Gramineae, Hicriopteriaceae and Pteriaceae occupy important position, and Compositae and Cyperaceae also play a certain role. This indicates that its subtropical nature is very obvious as shrubs intrude rapidly into the community in tireless case, grass-heath will be replaced by bush. It must be realized that diversification is an appropriate measure for the rational utilization of this grass-heath, including agriculture, forestry and animal husbandry etc. and their combination according to concrete condition of different regions.