| 摘要: |
| 为研究林龄对桉树人工林土壤碳 (C)、 氮 (N)、 磷 (P) 等养分含量和易氧化有机碳 (ROC)
的影响及其垂直变化规律, 分析林龄对人工林土壤生态化学计量特征和碳稳定性的影响, 以雷州半岛不同林
龄 (7 a 生和 12 a 生) 尾叶桉 Eucalyptus urophylla 人工林为研究对象, 根据土层深度按 0 ~ 10 cm、 10 ~ 20
cm、 20~40 cm、 40~60 cm 和 60~100 cm 共 5 个层次分别采集土壤样品并测定土壤养分与有机碳含量。 结果
显示: (1) 12 a 生尾叶桉人工林土壤 ROC、 总有机碳 (TOC)、 总氮 (TN) 和总磷 (TP) 比 7 a 生分别高
72. 64%、 114. 07%、 225. 69%和 14. 41%, 说明尾叶桉人工林土壤 TOC 含量和养分水平随着林龄的增加而提
高; (2) 12 a 生尾叶桉人工林表层土壤 (0~10 cm) 的 ROC/ TOC 显著大于 7 a 生 (P<0. 05), 说明前者表
层土壤的碳稳定性较低; 而 12 a 生尾叶桉底层土壤 (20~60 cm) 的 ROC/ TOC 值对比 7 a 低 36. 85%, 说明
12 a 生人工林底层土壤碳稳定性高于 7 a; (3) 相关性分析结果表明, 两种林龄人工林土壤 TOC 与 TN、 速
效磷 (AP) 和 C/ P 呈显著正相关, 且 7 a 生和 12 a 生人工林土壤 TOC 还分别受到 TP 和 N/ P 的显著影响。
土壤 ROC 与 TN、 C/ P 呈显著正相关, 其中 7 a 生和 12 a 生土壤 ROC 还分别受到 TP、 AP 和 N/ P 的显著影
响, 表明 7 a 生尾叶桉人工林土壤有机碳含量和碳稳定性受到土壤 P 元素供应的影响更大。 此外, 12 a 生人
工林土壤 ROC/ TOC 受到 TN 和 N/ P 的显著影响, 表明 12 a 生尾叶桉人工林则更容易受到土壤 TN 含量的
控。 因此, 在雷州半岛地区, 适当延长桉树人工林的轮伐周期, 并根据不同林龄改善土壤的氮磷养分供应
调
水
平, 有利于提高雷州半岛桉树人工林土壤的碳封存潜力。 |
| 关键词: 易氧化有机碳 土壤化学计量 尾叶桉 林龄 雷州半岛 |
| DOI： |
| 分类号: |
| 基金项目:广东省林业科技创新项目 (2022KJCX015、 2022KJCX017) |
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| Characteristics of Soil Carbon, Nitrogen, Phosphorus and Easily Oxidized Organic Carbon in Eucalyptus Plantations with Different Ages in Leizhou Peninsula |
|
Zhang Zhenyuan1, Gu Xiaojuan1, Wu Miaolan1, He Pulin2, Wang Zhonglin2, Xu Qixian2, Zhou Qing1, Mo Qifeng1
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1.College of Forestry and Landscape Architecture, South China Agricultural University;2.China Forestry Group Leizhou Forestry Bereau Co., Ltd
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| Abstract: |
| To investigate the impact of stand age on soil nutrient content carbon (C), nitrogen ( N),
phosphorus (P), etc. , and readily oxidizable carbon (ROC) in Eucalyptus plantations, we analyzed the ecological stoichiometry and C stability of soils at different depths in two Eucalyptus urophylla plantations (7 years
and 12 years old) in the Leizhou Peninsula. Soil samples were collected at five layers, 0-10 cm, 10-20 cm,
20-40 cm, 40-60 cm, and 60-100 cm, for analyzing soil nutrient content and organic C. The results showed
that: (1) ROC, total organic C (TOC), total N (TN), and total P (TP) of Eucalyptus urophylla plantation with 12 a were 72. 64%, 114. 07%, 225. 69%, and 14. 41% higher than those with 7 a, respectively, indicating that the soil TOC content and nutrient concentration of E. urophylla plantation increased with the increase of stand age. (2) The ROC/ TOC of the surface soil (0-10 cm) of E. urophylla plantation with 12 a
was significantly higher than that with 7 a (P<0. 05), indicating that the soil C stability of 12 a plantation was
lower, while the ROC/ TOC of the bottom soil (20-60 cm) of E. urophylla with 12 a was 36. 85% lower than
that with 7 a, suggesting that the C stability of 12 a was higher than that of 7 a. (3) The correlation analysis
showed that there was a significant positive correlation between soil TOC and TN, available P (AP), C/ P in
two plantations, and the soil TOC of 7 a and 12 a plantations was also significantly affected by TP and N / P; respectively. Soil ROC showed a significant positive correlation with TN and C/ P, and 7 a and 12 a plantations
were also significantly affected by TP, AP and N / P, respectively, indicating that the TOC content and C stability of 7 a were more affected by the supply of soil P elements. In addition, soil ROC/ TOC of 12 a plantation
was significantly affected by TN and N / P. The results show that the TOC content and C stability of 12 a were
more easily regulated by soil TN content. Therefore, appropriately extending the rotation cycle of Eucalyptus
plantations and improving the soil N and P supply levels according to different stand ages are conducive to improving the soil C sequestration potential of Eucalyptus plantations in the Leizhou Peninsula. |
| Key words: readily oxidized carbon soil stoichiometry Eucalyptus urophylla stand ages Leizhou Peninsula |
