不同覆盖处理对油茶细根生长与死亡的影响

目的 研究不同覆盖处理对油茶细根生长、死亡的影响，为油茶水分管理提供依据。 方法 采用微根管动态监测技术，以"长林4号"油茶林为试材，设置了黑地膜、油茶壳、花生秆+稻草、生态膜以及对照（无覆盖）5种处理，对林地0~40 cm土壤剖面的油茶细根进行了为期1年的观测。 结果 表明：花生秆+稻草处理和黑地膜处理显著增大了油茶活细根的总根长、总根尖数以及总表面积，其中以花生秆+稻草处理最优；但对活细根平均直径的促进作用却以黑地膜最为显著。4种覆盖处理死细根的总根长、总根尖数以及总表面积均大于对照；与对照处理相比，4种覆盖处理都有助于减小死细根的直径，且差异显著。油茶活细根的总根长、总根尖数以及总表面积在3月和6-7月出现峰值；而死细根的总根长、总根尖数以及总表面积在春季变化较平缓，而后缓慢上升。油茶细根的净生长速率呈先上升后下降趋势，在5-6月出现峰值。花生秆+稻草处理和黑地膜处理显著提高了油茶细根的年净（根长）生产力，其中花生秆+稻草处理作用最为明显。 结论 夏季为油茶细根生长和死亡的高峰期，花生秆+稻草处理对促进油茶活细根根量和年净（根长）生产力的作用最显著，黑地膜处理对促进油茶活细根直径的增大效果最明显。

Effects of Different Cover Treatment on the Growth and Death of Fine Roots of Camellia oleifera

Objective To study the effects of cover treatment on the growth and death of fine root of Camellia oleifera. Method Using minirhizotron dynamic monitoring technology, and taking C. oleifera "Changlin 4" forest as test material, four treatments (black mulch film, Camellia shelll, peanut rod + straw, ecological film) and the control (no cover) were set up. The fine roots of C. oleifera in the 0~40 cm soil profile were observed for one year. Result The results indicated that the treatments of peanut stalk + straw and black mulching significantly increased the total root length, total root tip number and total surface area of the fine roots of C. oleifera, and peanut stalk + straw treatment was the best. However, the black mulch treatment had the most pronounced effects in promoting the average diameter of the live fine roots. The total root length, total root tip number and total surface area of fine roots treated with any of the four treatments were larger than that of the control. Compared with the control treatment, all the four cover treatments contributed to reducing the diameter of the dead fine roots, and the difference was significant. The total root length, total root tip number and total surface area of fine roots of C. oleifera peaked in March and June to July. The total root length, total root tip number and total surface area of the dead fine roots changed more gently in the spring and then slowly increased. The net growth rate of fine roots of C. oleifera increased at first and then decreased, peaked from May to June. The peanut stalk + straw treatment and black mulching treatment significantly increased the annual net (root length) productivity of fine roots of C. oleifera, while the treatment of peanut stalk + straw was the most obvious. Conclusion Summer is the peak period of fine root growth and death of C. oleifera. The peanut stalk + straw treatment has the most significant effect on promoting the fine root amount and annual net (root length) productivity of C. oleifera, and the black mulching treatment has the most obvious effect on promoting the diameter increase of fine roots of C. oleifera.