摘要
沙地柏 (Sabina vulgaris)系毛乌素沙地唯一的天然常绿沙生灌木 ,也是一种有代表性的克隆植物 ,对沙地环境具有很强适应性。为了研究不定根对沙地柏生长和资源获得的重要性 ,通过切断匍匐茎 ,以分析模拟干扰对沙地柏子株存活、生长、生物量分配、气体交换和资源利用效率的影响。结果表明 :1)切断匍匐茎对沙地柏子株存活率无明显影响 ,这表明已定居的子株能够独立存活 ;2 )切断匍匐茎对当年生枝生长和生物量分配的影响受模拟干扰和环境水分状况的双重制约 ,流动沙地上比茎长随干扰强度的增加而显著增大 ,这有利于子株寻找到优越的微环境 ;3)固定沙地上 ,切断匍匐茎对当年生枝气体交换和资源利用效率的影响均不显著 ,而显著影响生物量分配 ,这种格局表明切断匍匐茎对沙地柏子株的影响可能具有层次性 ;4)气孔导度减小、资源利用效率提高可能是沙地柏子株对强度干扰的一种生理适应。
Sabina vulgaris is a unique evergreen shrub and a typical clonal species of the Mu Us sandy region. The importance of adventitious roots in the growth and r esource acquisition in this species was investigated: the effects of simulated d isturbance on survival, growth, biomass allocation, gas exchange and resource us e efficiency in S. vulgaris daughter plants were analyzed through artificial stolon severance. The results showed: 1) severance had little effect on surviv al rate of daughter plants, suggesting the resource independence of established daughter plants; 2) the impact of stolon severance on growth and biomass allocat ion in the current year's shoots was affected by both simulated disturbance and the water regime in the environments; specific stem length increased significan tly with increasing disturbance intensity in areas of shifting sand, enabling an improved chance for plants in these areas to encounter a favorable microhabitat ; 3) in areas of stable sand, the effects of stolon severance on gas exchange an d resource use efficiency were not significant, but the direction of its effect on biomass allocation was opposite, which may be related to a hierarchy of expre ssion of the stolon severance effects; 4) stomatal conductance decreased with in creasing disturbance intensity,while resource use efficiency followed the opposi te direction.
出处
《植物生态学报》
CAS
CSCD
北大核心
2000年第4期391-395,共5页
Chinese Journal of Plant Ecology
基金
中国科学院资源与生态环境研究重大项目和重点项目资助!( KZ95 1-B1-10 8
KZ95 2 -S1-12 6)
关键词
毛乌素沙地
沙地柏
资源利用效率
干扰
不定根
Mu Us sandland, Sabina vulgaris , Stolon severance, Survival, Growth, Biomass allocation, Gas exchange, Resou rce use efficiency
