沙棘人工林早衰及其更新复壮

针对沙棘人工林大面积早衰问题，在分析其特征、成因的基础上提出更新复壮途径。结果表明:沙棘人工林早衰表现为寿命缩短、生长和繁殖能力下降，形成原因主要包括干旱胁迫、造林密度大、不合理的造林设计等。考虑沙棘克隆习性与生境异质性的耦合作用，可通过及时平茬、配方施肥（激素）、异质性造林设计、径流林业技术促进营养生长和克隆繁殖，从而达到更新复壮或长期维持种群稳定性和克隆持久性之目的。今后应加强沙棘人工林早衰及平茬更新机制研究，为种群持久性维持及早衰种群的复壮提供依据。

Premature Senescence and Rejuvenation of Hippophae ssp. Plantation

Aiming to solve the problem of premature senescence occurring in a large area of Hippophae ssp. plantation, based on the analysis of the cause of its characteristics, rejuvenation ways for the plantations were discussed. The main features of premature senescence were shortened life expectancy, reduced abilities of growth and reproduction. These were resulted from drought stress, high planting density, and unreasonable afforestation design. Owing to Hippophae ssp.’s cloning habits and coupling effects of habitat heterogeneity, effective rejuvenation approaches were proposed, such as timely stumping, formula fertilization (hormones), heterogeneity afforestation design and runoff forestry technology to promote vegetative growth and clonal propagation, to maintain long-term population stability and cloning persistencey. It was suggested in the future to strengthen the researches in mechanism of premature senescence and rejuvenation, in order to provide evidence for it’s population persistency and rejuvenation.