| Pistacia chinensis Bunge (Anacardiaceae) is broadly used as energy resources, timber and landscaping tree species. The dioecious plants are widely distributed in nature. Female and male plants have different resource requirements from the environment. Plants showed different phenotypes and ecological effects between female and male. However, population structure of gender-related research of P. chinensis is not reported.The method which combined stationary plots and temporary plots was used to investigate population sex ratio, spatial distribution pattern and spatial relationship in the dioecious tree species P. chinensis. The effect of environmental factors was Analyzed on population sex ratio and spatial distribution pattern of females and males within a 100 m×140 m research plot and 28 different habitat temporary plots in Jiyuan city, Henan province. Gender, trees size and climate factors on the radial growth of dioecious P. chinensis trees were analyzed. The research results could provide theory reference for building of energy forest, artificial stand improvement and scientific operating.The results are shown as follows:It was tested whether the population sex ratio were significant biased 1:1 or not with chi-square test. There are 526 females,1200 males and 390 undetermined trees in 2116 P. chinensis individuals >4cm in dbh. The sex ratio (males/females) was 2.28, which demonstrated a significant male-biased sex ratio. Population sex ratio was significant male-biased in temporary plots of sunny slope. Population sex ratio of reproductive trees was significant male-biased in small diameter classes, and was not significant biased 1:lin other diameter classes.Spatial distribution pattern and spatial relationship was investigated in the dioecious tree species P. chinensis within a 100 mx 140 m research plot with the spatial point pattern analysis. Sapling, females and males of P. chinensis showed significant clumped distribution in space. P. chinensis saplings were significantly positively correlated with female and male P. chinensis trees at small scales (1-7m). Female trees showed significant repulsion against male trees, and population exhibited spatial segregation of the sexes. Spatial distribution pattern was detected in the dioecious tree species P. chinensis in temporary plots with aggregation indexes. Females and reproductive trees of P. chinensis mostly showed significant clumped distribution, and the difference of habitat affected female and male P. chinensis spatial distribution pattern significantly. Females and males of P. chinensis showed significant clumped distribution in low light intensity environment.The relationship was tested between population sex ratio, population density and local stand density within a 100m×140m research plot and the effect of environmental factors on sex ratio was analyzed within temporary plots in the dioecious tree species P. chinensis with GLM model. Population sex ratio was increased significantly with increasing density of reproductive trees, population density and stand density, which showed significant density dependence. The correlation analysis indicated that population sex ratio has a significantly negative correlation with soil moisture, a significantly negative correlation with total N, total P, total K and LAI.The relationship was analyzed between aggregation intensity and pattern type and environmental factors with Pearson correlation coefficient. Aggregation intensity and pattern type of females has a significantly positive correlation with LAI, which was decreased significantly with increasing light intensity. Aggregation intensity and pattern type of males and reproductive trees has a significantly negative correlation with total K.An integrative dendroclimatic approach was used to analyze the effects of gender, trees size and climate factors on the radial growth of dioecious P. chinensis trees. There is no significant effect of sex on radial growth of P. chinensis. The tree size significantly affected radial growth result in male and female plants with different diameter show different radial growth rate, radial growth rate was significant larger in female than in male in dbh classes 10-15cm. Correlation analysis between annual tree-ring residual chronology and climate factors indicated similar responses to climate factors between males and females. Radial growth in females and males was positively related to monthly minimum temperature in current March, mean temperature and monthly maximum temperature in current November and monthly precipitation in current May. However, radial growth in females and males was negatively related to mean temperature and monthly maximum temperature in current May. There were a little bit different responses to climate factors between males and females. Radial growth in females was negatively related to mean temperature in January, but radial growth in males was positively related to monthly minimum temperature in current April and was negatively related to mean temperature and monthly maximum temperature in current July.
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