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林业科学 ›› 2021, Vol. 57 ›› Issue (4): 24-31.doi: 10.11707/j.1001-7488.20210403

• 论文与研究报告 • 上一篇    下一篇

不同更新方式对亚热带常绿阔叶林土壤氮矿化的影响

高艳丽,杨智杰*,张丽,熊德成   

  1. 福建师范大学地理科学学院 福建三明森林生态系统与全球变化野外科学研究站 福州 350007
  • 收稿日期:2019-10-08 出版日期:2021-04-25 发布日期:2021-05-21
  • 通讯作者: 杨智杰
  • 基金资助:
    国家自然科学基金项目(31130013);国家自然科学基金项目(31670623)

Effects of Different Regenerated Models on Soil Nitrogen Mineralization in Subtropical Evergreen Broad-Leaved Forest

Yanli Gao,Zhijie Yang*,Li Zhang,Decheng Xiong   

  1. School of Geographical Sciences, Fujian Normal University Sanming Research Station of Forest Ecosystem and Global Change, Fujian Fuzhou 350007
  • Received:2019-10-08 Online:2021-04-25 Published:2021-05-21
  • Contact: Zhijie Yang

摘要:

目的: 探索亚热带米槠常绿阔叶林转换为人促更新林和人工林后的土壤氮矿化作用的变化,为评价和选择森林经营方式提供参考。方法: 以亚热带米槠常绿阔叶天然林、人促更新常绿阔叶林和米槠人工林为研究对象,比较不同森林类型表层(0~10和10~20 cm)土壤的铵态氮(NH4+-N)和硝态氮(NO3--N)含量,并采用室内氮矿化培养方法测定土壤氮矿化速率,研究不同经营方式对森林土壤氮矿化作用的影响。结果: 天然林转换为人促更新林和人工林后,0~10和10~20 cm土层土壤NH4+-N含量分别下降5%~13%和16%~25%,NO3--N含量分别增加1.4%~241%和68%~871%,且人促更新林NH4+-N含量比人工林高3%~27%,人促更新林NO3--N含量比人工林低40%~65%;天然林转换后,人促更新林和人工林土壤净氮矿化速率分别下降11%~12%和27%~50%,人促更新林土壤净氮矿化速率显著高于人工林,净硝化速率显著低于人工林。结论: 与人工林相比,人促更新营林方式的干扰活动程度低,林地凋落物养分归还量大,同时土壤净氮矿化速率高且硝化速率低,向土壤输入更多的有效性氮源。因此,人促更新方式有利于土壤氮保存和提高氮素有效性,在氮素养分循环方面比人工林经营方式更具有优越性。

关键词: 森林转换, 营林方式, 人促更新林, 土壤氮矿化作用, 土壤硝化作用, 亚热带森林

Abstract:

Objective: The purpose of this study was to explore the changes of soil N mineralization after the conversion of subtropical evergreen broad-leaved forest of Castanopsis carlesii to plantation or forest naturally regenerated with artificial enhancement in order to conclude the advantages in N cycling of artificial enhancement of regeneration over the traditional plantation management, therefore to provide a basis for evaluation and selection of forest management models. Method: Natural evergreen forest of Castanopsis carlesii(NF), artificially regenerated secondary forest(AR), and Castanopsis carlesii plantation (CC) in Sanming City, Fujian Province were studied. Soil ammonium nitrogen(NH4+-N), nitrate nitrogen (NO3--N) concentrations, and soil N mineralization rate in the surface layer (0-10 and 10-20 cm) among three forest types were compared. Result: The conversions of NF to AR and CC decreased soil NH4+-N, but increased NO3--N concentration. Compared with NF, the NH4+-N concentration decreased by 5%-13% and 16%-25% in the soil of 0-10 and 10-20 cm respectively, and the NO3--N concentration increased by 1.4%-241% and 68%-871% respectively. The NH4+-N concentration of the AR was 3%-27% higher than that of the CC, and the NO3--N was lower by 40%-65%. Soil net N mineralization rate of the AR and the CC was lower by 11%-12% and 27%-50% after the forest conversion, respectively. The soil net nitrogen mineralization rate of AR was significantly higher than that of CC, and the net nitrification rate was significantly lower than that of CC. Conclusion: Compared to the plantation, the artificial regeneration model caused lower human disturbances on soil leading to a higher return of litter nutrients, a higher soil net nitrogen mineralization rate, and a lower net nitrification rate. This results in a high content of inorganic N and improves soil N availability in AR. Therefore, the model of natural regeneration with artificial enhancement is beneficial to soil nitrogen preservation and improvement of nitrogen availability, also advantageous over plantation management in terms of nitrogen cycling.

Key words: forest conversion, forest management models, natural regeneration with artificial enhancement, soil nitrogen mineralization, soil nitrogen nitrification, subtropical forest

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