干旱区研究 ›› 2019, Vol. 36 ›› Issue (2): 296-306.

• 土壤生态 • 上一篇    下一篇

沙地樟子松人工林土壤氮矿化特征#br#

孔涛,张莹,雷泽勇,王东丽,刘洋,于吉,吴丹   

  1. 辽宁工程技术大学,环境科学与工程学院,辽宁 阜新 123000
  • 收稿日期:2018-10-12 修回日期:2018-10-23 出版日期:2019-03-15 发布日期:2019-03-12
  • 通讯作者: 雷泽勇
  • 作者简介:孔涛(1981-),男,硕士生导师,副教授,博士后,主要从事土壤养分循环研究. E-mail: kongtao2005@126.com
  • 基金资助:
    国家自然科学基金(3157070941701325);辽宁省高等学校基本科研项目(LJ2017QL015)资助

Soil Nitrogen Mineralization under Pinus sylvestris var. mongolica Plantation on Sandy Soil

KONG Tao, ZHANG Ying, LEI Ze yong, WANG Dong li, LIU Yang, YU Ji, WU Dan   

  1. College of Environmental Science and Engineering, Liaoning Technical University, Fuxin 123000, Liaoning, China
  • Received:2018-10-12 Revised:2018-10-23 Online:2019-03-15 Published:2019-03-12

摘要: 土壤氮(N)的有效性是沙地林生态系统生产力和稳定性的关键限制因子。本研究以科尔沁沙地樟子松人工林为研究对象,分析测定了10~60 a林龄土壤NH4+-N、NO3--N和矿质N含量、氨化速率、硝化速率和N矿化速率的变化规律。结果表明:樟子松人工林土壤NH4+-N、NO3--N和矿质N含量,随着不同林龄在10~60 a内表现出增加的趋势,其中10~30 a增幅较小,40~60 a显著提高;随着土层深度增加而减小,主要集中在0~20 cm,呈现出表聚性。不同林龄樟子松人工林土壤氨化速率、硝化速率和矿化速率均随林龄增加而增加,随土层深度的增加而降低,其中0~40 cm土层明显大于40~100 cm。通过双因素方差分析,得出林龄与土层对各矿化指标影响显著。土壤矿化指标与人工林地上樟子松株高、胸径、冠幅以及土壤有机碳、全氮、碱解氮有显著的正相关关系。通过冗余分析(RDA)表明,影响不同林龄土壤矿化指标的主要环境因子为全氮、全磷、有机碳;影响不同土层土壤矿化指标的主要环境因子为全氮、碱解氮、有机碳。因此,樟子松人工林能够改善沙地土壤N的有效性,幼龄林和中龄林改善效果较小,近成熟林和成熟林改善效果明显;对表层土的改善效果优于深层土;土壤肥力是影响土壤矿化指标的主要环境因子。

关键词: 风沙地, 林龄, 樟子松 (Pinus sylvestris var. mongolica), 人工林, 矿质氮, 氨化速率, 硝化速率, 氮矿化速率

Abstract: The availability of soil nitrogen (N) is a key limiting factor for the productivity and stability of sandy forest ecosystems. In this study, the changes of NH4+-N、NO3--N and mineral N contents and the ammoniation, nitrification and nitrogen mineralization rates of soil under the Pinus sylvestris var. mongolica plantations with 10-60year stand ages were determined. The results showed that the NH4+-N、NO3--N and mineral N contents of soil under the P.sylvestris plantations were increased with the increase of forest stand age in a range of 10-60 years, in which the increase under the plantations with 10-30year stand ages was low, and it was significantly improved under the plantations with 40-60 year stand ages. Soil NH4+-N、NO3--N and mineral N contents were decreased with the increase of soil depth, and they were distributed mainly in 0-20 cm soil layers. The soil ammoniation, nitrification and mineralization rates under the plantations were increased with the increase of forest stand age, and these indexes of the 0-40 cm soil layer was obviously higher than those of 40-100 cm soil layer. The two factor analysis of variance revealed that the effects of forest stand age and soil layer on the mineralization indexes were significant. Soil mineralization indexes had a significant positive correlation with plant height, diameter at breast height, crown width and the contents of soil organic carbon, total nitrogen and alkali nitrogen in the plantations. The redundancy analysis showed that the main environmental factors affecting soil mineralization indexes under the plantations with different stand ages were total nitrogen, total phosphorus and soil organic carbon; the main environmental factors affecting mineralization indexes of different soil layers were alkali hydrolyzable nitrogen, total phosphorus and soil organic carbon. Therefore, the P.sylvestris plantation could be used to improve the soil N in sandy land, the improvement effect of young and middle aged plantations on soil N was small, and that of nearmature forest and mature forest was obvious. The improvement effect of plantation on topsoil was better than that of deep soil. Soil fertility was the main environmental factor affecting soil mineralization index.

Key words: aeolian sandy land, stand age, Pinus sylvestris var. mongolica plantation, ammoniation rate, mineral nitrogen, nitrification rate, N mineralization rate