砒砂岩区沙棘林缓冲带细根及土体抗崩解特征

Fine Roots and Anti-disintegration Characteristics of Buffer Zone of Hippophae rhamnoides in Feldspathic Sandstone Area

探讨砒砂岩区不同宽度沙棘缓冲带生态调控效益的差异,对有效防治土壤侵蚀生态建设具有现实意义。采用野外典型取样和室内测定方法,研究了缓冲带内及带外下坡土层的物理化学性质、土壤崩解速率和缓冲带内沙棘细根的比根长变化特征。结果表明,随着缓冲带宽度的增加,缓冲带带内及带外下坡土壤的物理及化学性质优化程度逐渐提高。随沙棘缓冲带带宽的逐渐增加,土壤内细根的比根长也随之增加。沙棘缓冲带能有效降低沙棘缓冲带内及带外下坡土壤的崩解速率,并且带宽与土壤崩解速率呈负相关。比根长与崩解速率在0.05检验水平下显著负相关,当缓冲带带宽大于15 m时,林带内土壤中的细根比根长不再具有差异性,故15 m带宽的沙棘缓冲带为最适宽度。

It has practical significance to discuss the differences of ecological regulation effects of buffer zone of Hippophae rhamnoides among different widths in feldspathic sandstone area.Buffer zones with different width were taken as research object to analyze the physicochemical property of soil layers inside and outside buffer zones,the disintegration rate of soil and the change characteristics of specific root length of fine roots of Hippophae rhamnoides in buffer zones.The results show that with the increase of width of buffer zone,the optimization degree of physical and chemical properties of the soil has increased,as well as the specific root length of fine roots in the soil.Buffer zone of Hippophae rhamnoides can effectively decrease the disintegration rate inside and outside the buffer zone,the zone width is negatively correlated with the soil disintegration rate.The specific root length is significantly negatively correlated with the disintegration rate at 0.05 test level.There are no differences among the specific root length of fine roots in the soil when the width of buffer zone is bigger than 15 meters,so the best width of buffer zone of Hippophae rhamnoides is 15 meters.