Population Dynamics and Spectral Analysis of Rare-endangered Plant Juglans mandshurica in Shanxi Province
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Graphical Abstract
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Abstract
Based on the field data about Juglans mandshurica population and the theory of survival analysis and spectral analysis,the regulation of size-class and changing density was analyzed,and the static life table,the curves of survival,death,cumulative mortality rate,mortality density,hazard rate and killing valuable are drawn in this paper.At the same time,the population dynamics by spectral analysis were analyzed.The results showed:(1) the average density of J.mandshurica dropped with the increase of size-class,which reflected the negative association between density and size-class;(2) by F test,the curve of survival individuals tended to be the type DeeveyⅡ;(3) the monotony of cumulative mortality rate increases,while that of survival function decreases.The change of increase and decrease is that the beginning is higher than the later.This shows that in the beginning the mortality rate is higher,while at the later stage the population is relatively stable;(4) a regularity of periodic fluctuation in the process of natural regeneration of J.mandshurica population,while the basical regularity of periodic fluctuation was longer.(5) the main endangered cause is the disturbance by man.So it is very urgent to take efficient measures to protect and recover the endangered species.
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