雌雄异株树种黄连木种群性比及空间分布

Population sex ratio and spatial distribution of dioecious tree species Pistacia chinensis

研究了100m×140m固定样地内黄连木种群的性比格局和空间分布。结果表明,调查样地中dbh≥4cm的黄连木植株共有2116株,其中包括526株雌树,1200株雄树,性别未确定植株390株。黄连木性比(雄/雌=2.28)显著偏雄(P<0.001)。雌树和雄树平均胸径分别为7.34和7.81cm,雄树胸径显著大于雌树胸径(P<0.05)。黄连木幼树、雌树和雄树均呈显著聚集性分布。黄连木幼树与雌树、幼树与雄树均在较小尺度上表现为相互吸引;雌树与雄树则在空间上相互排斥,即雌树与雄树存在空间分离现象;黄连木不同大小以及不同性别植株之间主要表现为相互排斥。

An investigation was made on the population sex ratio and spatial distribution of dioecious tree species Pistacia chinensis within a 100 m × 140 m plot. In the plot, there were 2116 P. chinensis individuals with diameter at breast height （dbh） ≥4 cm, among which, 526 were females, 1200 were males, and 390 were undetermined. The sex ratio （males/females） was 2.28, indicating a significant male-biased sex ratio （P〈0. 001 ）. The average dbh of the females and males was 7. 34 cm and 7. 81 cm, respectively, and the difference was significant （P〈 0.05 ）. The saplings, females, and males all showed a significant clumped distribution. The saplings showed significant attraction to the females and males at small scales, while the females showed significant repulsion against the males at 0-50 m scales, i. e. , the females and males exhibited spatial segregation. A significant repulsion also exhibited between different size and different sex individuals.