干旱区研究 ›› 2024, Vol. 41 ›› Issue (3): 444-455.doi: 10.13866/j.azr.2024.03.09

• 水土资源 • 上一篇    下一篇

祁连山典型植被土壤碳、氮、磷含量及生态化学计量特征的垂直变化

白丽丽1(), 王文颖2,3(), 德却拉姆2, 刘艳方1, 邓艳芳4   

  1. 1.青海师范大学地理科学学院,青海 西宁 810008
    2.青海师范大学生命科学学院,青海 西宁 810008
    3.青藏高原生物多样性形成机制与综合利用省级重点实验室,青海 西宁 810008
    4.祁连山国家公园青海服务保障中心,青海 西宁 810008
  • 收稿日期:2023-08-10 修回日期:2023-10-23 出版日期:2024-03-15 发布日期:2024-04-01
  • 通讯作者: 王文颖. E-mail: wangwy0106@163.com
  • 作者简介:白丽丽(1990-),女,博士研究生,主要从事草地生态学研究. E-mail: Lilysx@163.com
  • 基金资助:
    第二次青藏高原综合科学考察研究(2019QZKK0502);2021年第一批中央林草生态保护恢复资金自然资源调查监测项目(2021QHXH017);青海省2021年度第一批中央引导地方科技发展专项资金(2021ZY002)

Elevational variations in ecological soil C, N, and P stoichiometry among five typical vegetation types in the Qilian Mountains

BAI Lili1(), WANG Wenying2,3(), Dequelamu 2, LIU Yanfang1, DENG Yanfang4   

  1. 1. College of Geographical Science, Qinghai Normal University, Xining 810008, Qinghia, China
    2. College of Life Science, Qinghai Normal University, Xining 810008, Qinghia, China
    3. Provincial Key Laboratory of Biodiversity Formation Mechanism and Comprehensive Utilization in Qinghai-Tibet Plateau, Xining 810008, Qinghai, China
    4. Qinghai Service and Guarantee Center of Qilian Mountains National Park, Xining 810008, Qinghia, China
  • Received:2023-08-10 Revised:2023-10-23 Online:2024-03-15 Published:2024-04-01

摘要:

本研究针对祁连山国家公园山体沿海拔(2700~4043 m)自下而上出现的针叶林、草甸化草原、高寒灌丛、高寒草甸、流石滩稀疏植被5种典型植被,研究土壤碳、氮、磷含量及生态化学计量比垂直分异规律,为祁连山国家公园生态系统土壤碳氮磷生物地球化学循环过程提供数据参考和科学依据。结果表明:(1) 祁连山山体垂直带上0~40 cm土壤总碳、总氮和总磷含量分别为15.33~83.46 g·kg-1、1.63~7.76 g·kg-1、0.41~0.66 g·kg-1。土壤总碳和总氮含量均表现为针叶林>草甸化草原>高寒灌丛>高寒草甸>流石滩稀疏植被,都是沿着海拔的升高显著降低。土壤全磷含量表现为高寒灌丛显著高于高寒草甸,其余植被间差异不显著。(2) 0~40 cm土壤铵态氮、硝态氮、速效磷含量分别为11.01~14.73 mg·kg-1、2.78~12.46 mg·kg-1和4.35~13.57 mg·kg-1。土壤铵态氮含量在各植被类型间差异不显著,土壤硝态氮含量沿着海拔的升高而显著降低,土壤速效磷在流石滩稀疏植被中含量较高。(3) 0~40 cm土壤C:N、C:P和N:P含量分别为9.52~10.11、29.89~320.24和3.18~29.63,土壤C:N沿着海拔升高逐渐降低,土壤C:P和N:P在流石滩稀疏植被中显著低于其他植被,潜在指示碳和氮是流石滩限制性养分元素,但相对于碳和氮,流石滩是一个富磷的环境。海拔综合多种环境因子变化,显著影响土壤碳、氮、磷的生物化学过程。

关键词: 植被类型, 海拔, 土壤理化性质, 生态化学计量, 祁连山

Abstract:

Five typical vegetation types (i.e., coniferous forests, meadow grasslands, alpine shrubs, alpine meadows, and sparse vegetations of limestone flat) along a vertical belt of the Qilian Mountains were selected to explore the spatial elevational patterns of soil carbon, nitrogen, and phosphorus and their stoichiometric ratios. Results showed that: (1) The contents of total carbon (C), nitrogen (N), and phosphorus (P) at the 0-40 cm depth were 15.33-83.46, 1.63-7.76, and 0.41-0.66 mg·kg-1, respectively. Soil C and N decreased gradually with increasing altitudes, following the order coniferous forests>meadow steppes>alpine shrubs>alpine meadows>sparse vegetations of limestone flat. Soil P in alpine scrubs was significantly higher than that in alpine meadows, but the other three vegetations showed no significant difference. (2) The contents of $\mathrm{NH}_{4}^{+}-\mathrm{N}$, $\mathrm{NO}_{3}^{-}-\mathrm{N}$ and available phosphorus at the 0-40 cm depth were 11.01-14.73, 2.78-12.46, and 4.35-13.57 mg·kg-1, respectively. Ammonium was the main inorganic nitrogen form in all vegetation types. The nitrite content decreased gradually with increasing altitude. The content of soil available phosphorus was higher in sparse vegetations of limestone flats. (3) The ratios of soil C:N, C:P, and N:P at the 0-40 cm depth were 9.52-10.11, 29.89-320.24, and 3.18-29.63, respectively. Soil C:N decreased with elevation. Soil C:P and N:P were significantly lower in the soil of sparse vegetations of the limestone flat than in other vegetations, indicating that carbon and nitrogen were the limiting nutrients in the limestone flat. By contrast, the limestone flat was in a phosphorus-rich state. Elevational variations in soil C, N, and P contents and their stoichiometric ratios reflect the joint control of multiple environmental factors, thereby affecting the biochemical processes of soil C, N, and P.

Key words: vegetation type, elevations, soil physicochemical properties, eco-stoichiometry, Qilian Mountains