【摘要】 近年在金沙江干热河谷及其邻近地区陆续发现的苏铁天然植物群落,为本属植物在欧亚大陆内陆分布的最北边缘。其中,面积最大和保存较好的是渡口市攀枝花苏铁(Cycas panzhihuaensis)植物群落。本文研究了这个群落的分布与生境、生长状况、外貌、种类组成以及群落的综合特征等。认为具有稀树草原的特点,而这里的稀树草原是次生性质的,苏铁群落是其中幸存的残遗植被类型。这对研究我国植物地理有着重要意义。更多还原

【Abstract】 The Cycas community is certainly a more primitive and ancient vegetation type in tropical and subtropical zones, but so far as inland Eurasia is concerned, it may extend to the boundary of Yunnan and Sichuan province, and make the most northern border line by itself. This paper deals with the natural community characters of Cycas panzhihuaensis which has been remained in mountain valley of Dukou City, Close to Jinsha River, at N. latitudes between 26° 36’-26°39’, E. longitudes between 101°33’-101°35’. With a total area about 310 hectares, this community is dispersed over there, occupying the altitude 1100-2000 m above sea level. Its habitat is a limestone mountain covered with dry open woodlands, that has resulted under a river valley climate with long dry and hot seasons (Nov.-May) . spreading largely to the repeated firing, grazing, and shifting cultivation.Based on the 30 plots of the investigated region, an association table are summarized and arranged. This table includes 104 species of the bryophyta and vascular plants, dominated by this Cycas and the others, c. g. Dodonaea angustifolia, Bauhinia delavayi, Pouzolzia elegans, Diospyros rnollifolia, as well as several tall grasses like Themeda hookeri, Eremopogon delavayi, Heteropogon contents etc.Common trees in this community are Quercus coc-ciferoides, Terminalia franchetii, Rhus succedanca, Pistacia weinmanni-folia and Phyllanthus emplica etc. We have analyzed the physiognomy, the structure and the measurements of community-presenee-coefficient among stands, only one vegetation type is considered as savanna.This community perhaps relict in nature bat its area has become narrower at present. Owing to the severe damage caused by human activities, care should be taken to protect strictly for its gradual recovering.更多还原