关键词: 艾比湖流域, 梭梭, 种群结构, 静态生命表, 存活曲线, 时间序列

Abstract: Aim Haloxylon ammodendron, a key shrub for sand fixation on parabolic dunes in the Ebinur Lake watershed, is highly resistant to wind erosion and sand burial, with strong ecological adaptability. Studying its population structure and dynamics can offer scientific insights for conserving Haloxylon ammodendron populations and promoting ecological sustainability in the watershed. Methods This study focuses on the Haloxylon ammodendron population in the Ebinur Lake watershed's parabolic dunes. Based on field surveys, it quantifies population dynamics using diameter - class substitution for age - class. It analyzes age structure via static life tables, survival curves, and survivorship functions, and forecasts future trends with time - series models. Important findings At present, the age structure of Haloxylon ammodendron populations is pyramidal, with a greater number of juvenile individuals than old ones, indicating robust regeneration. The survival curve of the population closely follows the Deevey-II type, meaning mortality risk is relatively evenly distributed across the life cycle. Fluctuations in population dynamic indices between adjacent age classes are pronounced, yet the population dynamic index that excludes external disturbances (Vpi) is higher than that which includes them (Vpi'), Vpi (35.17) > Vpi' (1.95) > 0, with Vpi' (1.95) approaching zero. Overall, the population is increasing, but its resistance to disturbance is weak. Survival rate (S(i)) declines monotonically with age, whereas cumulative mortality (F(i)) rises monotonically. Hazard rate (λ(ti)) exceeds the corresponding survival rate (S(i)) at every age, indicating a tendency toward decline in later life stages. Time-series projections show that after 2, 4, 6, and 8 age classes, the numbers of middle and high-aged individuals will rise, while younger age classes will provide ample recruitment in mid to late-growth phases. In summary, the Haloxylon ammodendron populations on parabolic dunes in the Ebinur Lake Basin are of the increasing type and possess growth potential. Their development is strongly influenced by regional environmental conditions; consequently, appropriate protective measures to enhance survival are recommended to promote natural regeneration.

Key words: Ebinur Lake basin, Haloxylon ammodendron, population structure, static life table, survival curve, time series