不同树龄油茶林分中土壤养分的变化特征及对细根生物量的影响

Changes of Soil Nutrients and Their Effects on Fine Root Biomass in Different Camellia oleifera Stands

以岑溪软枝油茶(Cenxi soft branch Camellia oleifera)无性系林分为研究对象,分析幼龄期(2年生)、结果初期(5年生)和盛产期(8年生) 3种林分中土壤养分的变化特征及对细根生物量的影响。结果表明:3种油茶林分中土壤养分总量差异显著,2年生油茶林分中有机质和水解性氮含量最高,5年油茶林分中有效磷含量最高,8年生油茶林分中速效钾含量最高。水平方向上,4种土壤养分在不同林地中分布较为均匀;垂直方向上,4种养分主要分布在土壤中上层0～30 cm处,整体上元素含量随着土层深度的加深而减少。偏相关分析表明:水解性氮对细根生物量的作用主要表现在40～60 cm土层;有效磷细根生物量的影响主要体现在10～40 cm土层,表现为不同程度的正相关性;速效钾对细根生物量的影响主要体现在10～20 cm土层中,表现为显著的负相关。有机质和有效磷与细根生物量呈极显著相关。

Changes of soil nutrients and their influence on fine roots of two-year-old, five-year-old and eight-year-old Cenxi soft branch Camellia oleifera clone stands were analyzed. Results showed that there was significant difference in soil nutrients of three C. oleifera stands. Both organic matter and hydrolyzable N were the highest in the two-year-old forest,available P content was the highest in the five-year-old forest,and available K content was the highest in the eight-year-old forest. The four soil nutrients evenly distributed in the horizontal direction in different forests. In the vertical direction,the four nutrients mainly distributed in the upper layer of the soil at 0~30 cm. The overall nutrients decreased with the increase of soil layer. Partial correlation analysis showed that effect of hydrolyzable N on fine root biomass could be found in the 40~60 cm soil layer. The effect of available P on fine root biomass could be found in 10~40 cm soil layer,and there was positive correlation to some extent. The effect of available K on fine root biomass couid be found in the 10~20 cm soil layer,and there was a significant negative correlation. The organic matter had a extremely significant relationship with fine root biomass.