生态环境学报 ›› 2022, Vol. 31 ›› Issue (5): 875-884.DOI: 10.16258/j.cnki.1674-5906.2022.05.003

• 研究论文 • 上一篇    下一篇

黄土高原不同植被密度条件下土壤水、碳、氮分布特征

张恒宇1,2(), 孙树臣1,*(), 吴元芝2,3,*(), 安娟, 宋红丽   

  1. 1.聊城大学地理与环境学院,山东 聊城 252000
    2.临沂大学资源环境学院/山东省水土保持与环境保育重点实验室,山东 临沂 276000
    3.中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京 100101
  • 收稿日期:2021-12-15 出版日期:2022-05-18 发布日期:2022-07-12
  • 通讯作者: 吴元芝(1982年生),女,副教授,博士,主要从事土壤物理与生态水文相关研究。E-mail: wuyuanzhi05@163.com
    * 孙树臣(1984年生),男,讲师,博士,主要从事土壤水分与植物相互作用关系研究。E-mail: shuchen@126.com;
    吴元芝(1982年生),女,副教授,博士,主要从事土壤物理与生态水文相关研究。E-mail: wuyuanzhi05@163.com
    * 孙树臣(1984年生),男,讲师,博士,主要从事土壤水分与植物相互作用关系研究。E-mail: shuchen@126.com;
    吴元芝(1982年生),女,副教授,博士,主要从事土壤物理与生态水文相关研究。E-mail: wuyuanzhi05@163.com
    * 孙树臣(1984年生),男,讲师,博士,主要从事土壤水分与植物相互作用关系研究。E-mail: shuchen@126.com;
    吴元芝(1982年生),女,副教授,博士,主要从事土壤物理与生态水文相关研究。E-mail: wuyuanzhi05@163.com
    * 孙树臣(1984年生),男,讲师,博士,主要从事土壤水分与植物相互作用关系研究。E-mail: shuchen@126.com;
  • 作者简介:张恒宇(1997年生),女,硕士研究生,主要从事土壤水分与植物作用关系研究。E-mail: 18765497953@163.com
  • 基金资助:
    中国博士后基金项目(2016M601118);国家自然科学基金项目(41701243)

Distribution Characteristics of Soil Water, Carbon and Nitrogen under Different Vegetation Densities in Loess Plateau

ZHANG Hengyu1,2(), SUN Shuchen1,*(), WU Yuanzhi2,3,*(), AN Juan, SONG Hongli   

  1. 1. School of Geography and Environment, Liaocheng University, Liaocheng 252000, P. R. China
    2. Key Laboratory of Soil and Water Conservation and Environmental Conservation/School of Resources and Environment, Linyi University, Linyi 276000, P. R. China
    3. Key Laboratory of Ecosystem Network Observation and Simulation, Institute of Geographical Sciences and resources, Chinese Academy of Sciences, Beijing 100101, P. R. China
  • Received:2021-12-15 Online:2022-05-18 Published:2022-07-12

摘要:

研究黄土高原典型植被不同密度条件下土壤水分、碳、氮剖面分布特征,探讨水、碳、氮剖面分布的耦合关系,为植被恢复密度选择提供依据。在神木县六道沟小流域,选取3个种植密度处理的柠条(Caragana korshinskii)林地和沙柳(Salix psammophyllum)林地,人工打土钻取样,分析土壤含水量、有机碳和全氮含量剖面分布特征。结果表明,(1)柠条林地剖面土层平均土壤含水量为低密度 (9.34%)>中密度 (8.35%)>高密度 (7.90%),土壤储水量也为低密度 (367.50 mm)>中密度 (326.98 mm)>高密度 (317.97 mm);沙柳林地剖面土层平均土壤含水量与储水量也均为低密度>中密度>高密度,分别为12.10、9.93、9.03%,502.48、400.30、361.03 mm;低密度柠条林地各土层含水量均为最高,且在100—150 cm和150—300 cm土层显著高于中、高密度,低密度处理沙柳林地各土层的含水量均显著高于高密度处理;各密度柠条林地及中、高密度沙柳林地在100 cm深度以下出现了土壤干燥化现象,且沙柳干燥化程度较柠条轻。(2)2种植被条件下土壤剖面有机碳和全氮含量的分布具有不同程度的表聚现象,柠条林地70 cm以上土层有机碳和全氮含量较深层高,而沙柳林地仅30 cm以上土层有机碳和全氮含量明显较高。两种植被各土层有机碳及全氮储量均为低密度处理最高,柠条林地分别为8.21、0.80 kg∙m-2,沙柳林地分别为6.60、0.65 kg∙m-2;高密度处理最低,柠条林地分别为5.39、0.60 kg∙m-2,沙柳林地分别为5.77、0.48 kg∙m-2,且各密度处理柠条林地的土壤有机碳和全氮储量均高于沙柳林地。(3)柠条林地土壤有机碳和全氮含量与土壤含水量呈显著正相关关系,且低密度处理土壤有机碳和全氮含量受土壤含水量的影响更加明显,但沙柳林地各密度处理土壤有机碳和全氮含量受土壤含水量的影响不明显。由以上结果可知,柠条林土壤有机碳和氮的积累高,但容易受到土壤干燥化的限制,进行植被恢复时要特别注意种植密度的控制。

关键词: 黄土高原, 植被密度, 土壤含水量, 有机碳, 全氮

Abstract:

This study examined the distribution characteristics of soil water, carbon, and nitrogen profile under different densities of typical vegetation on the Loess Plateau, explored the coupling relationship between the distribution of soil water, carbon, and nitrogen profile, and provided evidence for the selection of vegetation restoration density. In Liudaogou watershed of Shenmu County, three Caragana korshinskii and Salix psammophyllum forests were selected and sampled by artificial drilling to analyze the profile distribution characteristics of soil water, organic carbon, and total nitrogen contents. The results showed that (1) the average soil water content in the section of C. korshinskii forest indicated that low density (9.34%)>medium density (8.35%)>high density (7.90%). Soil water storage showed that low density (367.50 mm)>medium density (326.98 mm)>high density (317.97 mm). The average soil water content and water storage in the section of S. psammophyllum forest also indicated that low density>medium density>high density (12.10%, 9.93%, 9.03%, and 502.48 mm, 400.30 mm, 361.03 mm, respectively). The water content of all soil layers in the low density of the C. korshinskii forest was the highest, and was significantly higher in the 100-150 and 150-300 cm soil layers than in medium and high densities. The water content of each soil layer in the low density of S. psammophyllum forest was significantly higher than that in the high density treatment. The soil desiccant phenomenon occurred below 100 cm depth in every density of the C. korshinskii forest and the medium and high densities of the S. psammophyllum forest. The desiccant degree of S. psammophyllum was lighter than that of the C. korshinskii forest. (2) The distribution of organic carbon and total nitrogen contents in soil profile under planting conditions showed different degrees of surface aggregation. The contents of organic carbon and total nitrogen in the soil layer above 70 cm in the C. korshinskii forest were higher than those in the deeper layer, while the contents of organic carbon and total nitrogen in the soil layer above 30 cm in the S. psammophyllum forest were significantly higher than those in the deeper layer. The soil organic carbon and total nitrogen storage were the highest in the low-density treatment (8.21 and 0.80 kg∙m-2 in the C. korshinskii forest; 6.60 and 0.65 kg∙m-2 in the S. psammophyllum forest), but the lowest in high-density treatment (5.39 and 0.60 kg∙m-2 in the C. korshinskii forest; 5.77 and 0.48 kg∙m-2 in the S. psammophyllum forest). The soil organic carbon and total nitrogen storage in the C. korshinskii forest were higher than those in the S. psammophyllum forest. (3) Soil organic carbon and total nitrogen contents were significantly and positively correlated with soil water content in the C. korshinskii forest, and the effects of soil water content on soil organic carbon and total nitrogen contents were more evident under the low density treatment. In the S. psammophyllum forest, the soil organic carbon and total nitrogen contents under different density treatments were not significantly affected by soil water content. Based on these results, the accumulation of soil organic carbon and nitrogen in the C. korshinskii forest is high, but it is easy to be restricted by soil desiccation. Special attention should be paid to the control of planting density during vegetation restoration.

Key words: Loess Plateau, vegetation density, soil water content, organic carbon, total nitrogen

中图分类号: