黄土丘陵区天然杜松种群结构及动态分析

Population structure and dynamic analysis of natural Juniperus rigida in a loess hilly area

以内蒙古黄土丘陵区天然杜松种群为研究对象,通过静态生命表、生存函数、动态量化分析以及时间序列模型分析天然杜松种群结构和动态变化。结果表明:幼苗个体数量居多,中树其次,成树较少,结合种群数量动态变化指数Vpi>0,该种群则为增长型;存活曲线经曲线模型验证趋于Deevey-Ⅱ型,表明个龄级死亡率稳定;考虑外界干扰时动态指数趋于0,种群在干扰条件下增长不明显;生存函数分析种群表现为前期生存强中期稳定后期逐渐衰退的趋势;未来2~8各个龄级时间后,幼苗减少,中树和成树均增加;幼苗阶段对种群的更新和发展具有决定作用,建议对幼苗实施科学的保护措施,促进种群的更新。对杜松种群内在机制的研究,丰富了干旱区的植被建设,为杜松种群经营管理提供了参考,为黄土丘陵区植被的保护和恢复提供理论依据。

This study focused on the natural Juniperus rigida population in the loess hilly region of Inner Mongolia.The structure and dynamic changes of the population were analyzed using a static life table,survival function,dynamic quantitative analysis,and time series model.The results showed that the population mainly comprised many individual seedlings,followed by medium and less mature trees.Combined with the dynamic change index Vpi>0,the population was a growth type.The survival curve was verified using the curve model and tended to Deevey-II,indicating that the mortality rate of each age class was stable.Considering the external interference,the dynamic index tended to 0,and the population growth is not obvious under the interference condition.In the survival function analysis,the population showed a strong survival trend in the early stage,followed by a gradual decline in the middle stage.During the 2-to-8-year period,the number of seedlings decreased while middle-aged and adult trees increased.The seedling stage is crucial to the regeneration and development of the population.Therefore,implementing scientific protection measures for seedlings to promote population regeneration is recommended.Research on the internal mechanisms of the Juniperus rigida population can enrich vegetation construction in arid areas,provide a reference for population management,and provide a theoretical basis for vegetation protection and restoration in the loess hilly area.