土壤理化性质对红锥人工林生长及心材形成的影响

目的 研究土壤理化性质与红锥人工林生长及心材形成的相关性，以期为红锥人工林的立地选择和高价值心材定向培育提供科学依据。 方法 在广西凭祥市中国林业科学研究院热带林业实验中心红锥中龄林和近熟林内设置9块20 m × 30 m的样地，选取样地内优势木进行解析，分析其生长和心材特征，并采集0～20、20～40、40～60、60～100 cm 4个土层的土样，分析其理化性质，应用灰色关联分析研究土壤理化性质对红锥人工林生长及心材形成的影响。 结果 2个龄组红锥心材直径比分别为24.27%和49.33%，高度比分别为44.99%和45.99%，材积比分别为6.88%和14.94%。灰色关联分析表明：近熟林的胸径、树高和材积与土壤毛管孔隙度和总孔隙度的关联度最高，而中龄林的这些指标与非毛管空隙度和全磷含量的关联度最高。中龄林和近熟林心材特征与速效钾、全钾和有效磷含量的关联度最高。 结论 土壤毛管孔隙度、总孔隙度和非毛管孔隙度是影响红锥人工林生长的主要因子，土壤速效钾、全钾和有效磷含量是心材形成的主要影响因子。

Effects of Soil Physicochemical Properties on Growth and Heartwood Formation of Castanopsis hystrix Plantation

Objective To assess the relationships between the growth and heartwood formation of Castanopsis hystrix plantation and the physicochemical properties of soil so as to provide evidences for site selection and high-quality heartwood production of C. hystrix. Method Nine plots with size of 20 m × 30 m were set, and the growth of C. hystrix trees within each plot were investigated in middle-aged and near-matured pure C. hystrix plantations at the Experimental Centre of Tropical Forestry, Chinese Academy of Forestry in Pingxiang of Guangxi Zhuang Autonomous Region. The dominant trees were sampled, and the stem analysis were conducted to reveal their growth and heartwood properties. Meanwhile, soil samples were collected from 0-20 cm, 20-40 cm, 40-60 cm and 60-100 cm depths, respectively, to analyze the physical and chemical properties. Grey relationship analysis was applied to study the effects of soil physicochemical properties on the growth and heartwood properties of C. hystrix. Result The ratio of heartwood diameter, height and volume in the middle-aged and near-matured plantations were 24.27% and 49.33%, 44.99% and 45.99%, and 14.94% and 6.88%, respectively. It was indicated from Grey correlation analysis that the diameter at breast height, height and volume showed high coefficients with soil capillary porosity and total porosity in near-matured plantations, while with soil non-capillary porosity and total phosphorus content in middle-aged plantations. The heartwood properties showed high coefficients with the contents of total potassium as well as available potassium and phosphorus in both the middle-aged and near-matured plantations. Conclusion Soil capillary porosity, non-capillary porosity and total porosity are the main factors influencing the growth of C. hystrix plantations, and soil total potassium and available potassium contents are the main factors influencing the heartwood formation of C. hystrix.