立地条件对湖南山核桃产量与胸径的影响

对靖州县典型高产和低产的湖南山核桃林的产量、胸径及立地因子进行了调查．并对其进行了相关分析。结果表明：影响湖南山核桃林生长和产量的立地因子主要是母质、土壤类型和土层厚度。成土母质以页岩最好．其次是石灰岩、紫色页岩和砂岩；土壤以山地黄壤最好，其次是山地黄红壤、黑色石灰土、酸性紫色土；湖南山核桃的产量和胸径与土层厚度成一元线性回归关系．随着土层厚度的增加，湖南山核桃的产量和胸径有较明显的增加趋势。

Effect of Site Condition on Yield and Breast Diameter of Carya hunanensis

Field survey was conducted in the typical low yield Carya hunanensis forest of Jingzhou, with a view to identify the correlation of site condition and the nut yield and trunk diameter at breast height. The results indicated that the leading factors affecting the tree growth and nut yield are bedrock, soil type and soil depth. The most suitable bedrock is shale with limestone, purple shale and sandstone being the next optimal. The best soil is upland yellow soil, and the next is upland yellowish red soil, black limy soil and acidic purple soil. The depth of soil is positively correlated with the yield and breast diameter, which increase remarkably along with the soil depth deeper.