冶力关林区紫果云杉天然林种群结构特征

紫果云杉为我国特有树种，以冶力关林区的紫果云杉天然种群为对象，通过样地调查和数据统计，绘制种群结构图，编制静态生命表，分析存活曲线，运用数量化分析法研究种群动态，并用时间序列模型对种群数量动态进行预测，以揭示本区域紫果云杉的生存现状，为该物种的保护和经营提供理论依据。结果表明，紫果云杉幼苗占种群个体总数的21.05％，Ⅱ龄级时，个体数量迅速减少，幼苗死亡率达到80.40％，出现瓶颈现象，种群结构近似于纺锤型。总体来看，紫果云杉种群幼苗数量优势不明显，种群更接近于稳定型，种群存活曲线符合Deevey-Ⅱ型；未来2、4、6、8个龄级后，种群个体数量呈增长趋势，但增长性低，增长潜力小，并对外界干扰较敏感；竞争、自疏作用造成幼苗、幼树存活率偏低是影响紫果云杉种群自然更新关键因素，幼苗的分布状况也影响着种群的发展。散生的种群在自身比例较低的混交林中始终处于劣势地位，不利于种群增长。因此，须采取人工措施使种群形成规模，促进种群增长。

Population Structure Characteristics of Picea purpurea Natural Forest in Yeliguan Forest Area

Picea purpurea is a unique tree species in China.To determine the population survival status and dynamic characteristics,natural P.purpurea forests at Yeliguan forest area were taken as the research objects.Based on field survey and data analysis,a population structure diagram,static life table,and survival curve were drawn.Population survival status was determined by using quantity analysis method.The population dynamics were predicted by time-sequence model.The purposes of this study were to reveal the population structure,dynamic characteristics,and the survival status of P.purpurea in this region to provide a theoretical basis for the protection and management of the species.The results showed that the seedlings of P.purpurea population accounted for 21.05% of the total.The number of population individuals declined rapidly at Ⅱ age class,and mortality achieved 80.40% with emerged bottlenecks,population structure was close to the spindle-shape.Overall,numeral advantages of young individuals were not significant,and population structure was close to stable type,survival curve conformed to Deevey-Ⅱ.The number of P.purpurea individuals would increase after the 2,4,6 and 8 age classes with low growth and small growth potential,and sensitive to external interference.The low survival rate of the seedlings caused by the competition and self-thinning was the key factor to affect the natural regeneration of P.purpurea population,seedling distribution also affected population development.The disperse population was in disadvantage position for its low proportion in mixed forests,which inhibited the growth of the population.Therefore,artificial measures must be taken to make the population form scale and promote population growth.