阔叶树对红皮云杉人工林土壤营养状况的改善作用

Improvement of broadleaved tree species to soil nutrient conditions of Picea koraiensis plantations

【目的】研究红皮云杉人工林培育过程中林分地力的变化状况以及阔叶树对红皮云杉人工林土壤营养的改善作用,为红皮云杉人工林的培育筛选适宜的混交树种和施肥营养元素。【方法】在红皮云杉人工林和天然林中采集树叶、凋落物和土壤样品,实验室内使用碳氮分析仪测定样品C含量,凯氏定氮仪测定叶片和凋落物的N含量,连续流动分析仪测定土壤的N含量,硫酸-高氯酸消化-钼锑抗比色法测定样品P含量。【结果】(1)4种红皮云杉人工林间土壤的C、N、P含量差异显著,3种混交林均大于纯林,其中红皮云杉胡桃楸混交林C、N、P含量最大;(2)4种红皮云杉人工林间土壤的C∶N、C∶P差异显著,3种混交林均小于纯林,其中,红皮云杉胡桃楸混交林C∶N、C∶P最小;(3)混交树种叶片及其凋落物的N、P含量差异显著,以黄檗为最低,胡桃楸为最高,但均高于红皮云杉;(4)混交树种叶片及其凋落物的C∶N、C∶P以黄檗为最高,胡桃楸为最低,但均显著低于红皮云杉;(5)混交林中混交树种叶片及其凋落物与土壤之间C、N、P含量及C∶N、C∶P的相关性皆高于同林型中红皮云杉叶片及其凋落物与土壤之间C、N、P含量及C∶N、C∶P的相关性。【结论】依据树种叶片、凋落物及土壤部分的C含量、N含量、P含量、C∶N、C∶P和N:P,胡桃楸和水曲柳可做为红皮云杉人工林的适宜混交树种,培育过程中应注意解决N素和P素含量的不足。

[Objective] Exploring the changes of soil nutrient conditions and the improvement role of broadleaved tree species to the soil nutrients of Picea koraiensis plantations aims to select the suitable mixed species and fertilization elements for the cultivation of Picea koraiensis plantations. [Method] We collected the sample of leaf, litter and soil from Picea koraiensis plantations and natural forest in the sample plots, and used carbon nitrogen analyzer to determine the C content of the samples, used Kjeldahl instrument to determine the N content of leaves and litter samples, used the continuous flow analyzer to determine the N content of the soil samples, and used sulfuric acid-perchloric acid digestion-molybdenum antimony colorimetry to determine the P content of the samples. [Result](1) The difference of C content, N content and P content in the soil of four plantation types was significant, pure Picea koraiensis plantation was lower than three mixed plantations, and highest in Picea koraiensis-Juglans mandshurica mixed plantations.(2) The difference of C:N and C:P in the soil of four plantation types was significant, pure Picea koraiensis plantation was higher than three mixed plantations, and lowest in Picea koraiensis-Juglans mandshurica mixed plantations.(3) The difference of N content and P content in the leaf and litter of three mixed species was significant, lowest in Phellodendron amurense, and highest in Juglans mandshurica, but all of them were higher than that of Picea koraiensis.(4) The C:N and C:P in the leaf and litter of mixed tree species were highest in Phellodendron amurense and lowest in Juglans mandshurica, but all of them were obvious lower than that of Picea koraiensis.(5) The correlations of C content, N content, P content, C:N and C:P between leaf and soil as well as between litter and soil were higher in the mixed species than that in Picea koraiensis. [Conclusion] According to the C contents, N contents, P contents, C:N, C:P and N:P in the leaf,litter and soil parts of Picea koraiensis plantations, Juglans mandshurica and Fraxinus mandshurica should be prefer as the mixed tree species, more attention should be paid to the lack of N content and P content during the cultivation of Picea koraiensis plantations.