油蒿(Artemisia ordosica)对半干旱区沙地生境的适应及其生态作用

我国温带半干旱区沙地生境的主要特征是干旱少雨、沙源丰富和大风频繁,这种特定条件进化出我国特有的优良固沙植物--油蒿.在长期的进化过程中,油蒿形成了独特的形态结构、生理特征和繁殖习性,能够很好地适应沙地环境.油蒿群落不仅能够防风固沙,影响沙地生态系统的水分运移与分配,还能促进土壤的发育.因此,油蒿在适应沙地生境的同时对沙地产生巨大的影响和改造作用.油蒿群落对沙地生境的不断改造,推动了植物群落的演替,最终使流动沙丘转变为丰茂的植被.

ADAPTATION OF ARTEMISIA ORDOSICA TO TEMPERATE ARID SANDY LAND AND ITS ROLES IN HABITAT SHIFY

Such poor conditions in sandy land as little rain, enormous sand and frequent winds constitute great challenges to many plant species in Northwest of China. However, some plant species can still survive there and develop their distinctive adaptation to habitat. The endemic species Artemisia ordosica is one of the shrubs with super adaptation to sandy land for its morphological, physiological and reproductive characteristics. Not only can Artemisia ordosica adapt to sandy land, but also can improve or transform environment greatly. Community of Artemisia ordosica can weaken winds on the ground and prevent sand from drifting effectively, change the properties of soil water and evapotranspiration, and promote soil development. It is just due to the adaptation of Artemisia ordosica to sandy land and its roles in habitat shift that vegetation succession can be faciliated on shifting sand dunes, and those dunes can be transformed into productive vegetations in the end.