中国沙棘伐桩萌枝能力对平茬高度的响应

为探讨中国沙棘伐桩萌枝能力对平茬高度的响应规律及其生物量调控机制，以不平茬为对照，平茬高度为0、10、20 cm进行随机排列和拉丁方排列相结合的田间试验，对萌枝数量、萌枝生长、生物量投资格局、生物量分配格局在不同平茬高度之间的差异显著性进行检验，对萌枝能力与生物量投资的相关性状进行比较。结果表明：随平茬高度增大，萌枝数上升而存活率、生长量、生物量先升后降；萌枝数与存活率呈负相关，生长量与存活率具有负相关趋势，生长量与生物量呈正相关。与对照相比，平茬使克隆对根系和叶片的生物量投资与分配增大、树干和枝条生物量投资与分配减小。因此，平茬干扰通过刺激诱导伐桩不定芽和休眠芽萌发，通过加大根系和叶片生物量投资及分配促进萌芽生长，并在萌枝数、存活率、生长量权衡作用下形成不同平茬高度的萌枝格局。其中，平茬10 cm的萌枝存活率和生长量最大，且经过3个生长季生物量积累能力已显著超过对照（未平茬）。

Response of Sprouting Ability of Hippophae rhamnoides ssp. sinensis to Stubble Height

In order to explore the response law of stump sprouting capacity to stubble height and its biomass regulation mechanism of Hippophae rhamnoides ssp. sinensis, field experiments were carried out with a combination of random and latin arrangement with a stubble height of 0, 10, 20 cm, stem without stumping as control. The difference of sprout number, sprout growth, biomass accumulation and allocation pattern with different stubble heights were tested. The traits of tillering capacity and biomass accumulation were compared. The results showed that the number of sprouts increased with the increase of stubble height, while the survival rate, growth increment and biomass first increased and then decreased. The number of sprouts is negatively correlated with survival rate, there is a negative correlation trend between growth and survival rate, and the growth amount has a positive correlation with biomass. Compared with the control, the biomass accumulation and allocation of roots and leaves of stumping increased, and the biomass accumulation and allocation of trunk and branches decreased. These results indicated that the interference of stumping can stimulate the germination of adventitious buds and dormant buds, increase the biomass accumulation and allocation of root and leaf to promote the bud growth, and form the germination pattern of different stubble height under the trade off of the sprouting number, survival rate and growth increment. Among them, the survival rate and growth capacity of sprouting branches of 10 cm stubble height were the largest, and the biomass accumulation capacity of 10 cm stubble height after 3 growth seasons was significantly higher than that of the control (without stumping).