平茬高度对中国沙棘根蘖能力的影响

林木萌蘖与平茬高度关系的研究目前几乎局限于伐桩萌枝,为探讨中国沙棘根系萌蘖(根蘖数量、生长量、根系扩散)能力对平茬高度的响应规律及其生物量调节机制,对伐桩0、10、20 cm及未平茬(对照)的相关指标进行比较分析。结果表明:随平茬高度增大,根蘖能力及克隆生物量先升后降,且根蘖能力与水平根、垂直根、叶片生物量呈正相关。平茬使克隆对水平根、垂直根、叶片的生物量投资和分配加大,从而增强了根系萌蘖能力。其中,水平根对根蘖数量起主导作用、垂直根对根蘖生长起主导作用、叶片通过促进根系发育而起间接作用。由于水平根、垂直根、叶片生物量随平茬高度的增大先升后降,因此根蘖能力也呈先升后降趋势。

Response of Root Suckering Ability of Hippophae rhamnoides ssp. sinensis to Stubble Height

In order to explore the response law of root sprouting capacity(number of suckering,growth,root diffusion)and its mechanism of biomass regulation of Hippophae rhamnoides ssp.sinensis to the stubble height,comparative analysis of the relevant indexes of stump 0,10,20 cm and without stubble(control)were conducted.The results showed that the ability of root tiller and clonal biomass first increased and then decreased with the increase of stubble height,and the ability of root tiller was positively correlated with the biomass of horizontal root,vertical root and leaf.Stumping increased the biomass accumulation and allocation of clone to horizontal root,vertical root and leaf,thus enhancing the ability of root suckering.Among them,horizontal roots play a leading role in the number of root tillers,vertical roots play a leading role in the growth of root tillers,and leaves play an indirect role in promoting root development.As the biomass of horizontal root,vertical root and leaf increased first and then decreased with the increase of stubble height,the ability of root tiller also increased first and then decreased.