元江干热河谷肉质多利灌丛的研究

以内质多刺植物霸王鞭(Euphorbia royleana)和仙人掌(Opuntia monacantha)为特征的具有荒漠植被景观的元江干热河谷肉质多刺灌丛是一种特殊的次生植被,是在近代原生植被的强烈破坏下,栽培逸生的霸王鞭和仙人掌在局部特别千热土薄多石之处发展而形成的。该群落外貌和结构特殊,可初步定为一个群丛,下分两个亚群丛。在种类组成上,该群落与热带亚洲干早植物区系联系密切,在区系起源上具有古南大陆残余背景,在群落形成和发展上又与人为活动相联系。

A STUDY ON THE THORNY SUCCULENT SHRUBS IN DRY-HOT VALLEY OF YUANJIAN COUNTY

The thorny succulent thrubs in dry-hot valley of Yuanjian county arc special secondary shrubs with the characters of tropical desert vegetation. The shrubs distribute mainly in the area below alt. 600 m in the valley and grow on the drier and hotter rocky banks. The succulent genera Euphorbia and Opuniia together form the upper synusia of the shrub layer of the community and other many dry-hot resistant shrub species form the lower layer. Under the several human disturbances to the natural vegetation and malpractice, cultivated Euphorbia royleana and Opuntia monacantha intruded into the semi-savanna of the valley and formed the thorny succulent shrubs. The shrubs may be accepted as an association which can be divided into two subassociations. The flora of the shrubs has direct affinity with the xeric flora of tropical Asia and is considered to have the connection with Gondwana flora in its origin.With the continuation of severe human disturbance to the natural vegetation and malpractice, ecoclimate would become drier and hotter and the secondary shrubs would continuously develop in the valley.