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应用生态学报 ›› 2019, Vol. 30 ›› Issue (6): 1927-1935.doi: 10.13287/j.1001-9332.201906.001

• 研究报告 • 上一篇    下一篇

宁夏东部荒漠草原灌丛引入过程中土壤有机碳变化及其空间格局预测

赵亚楠1, 杜艳艳1, 马彦平1, 赵延兵1, 周玉蓉1, 王红梅1,2,*   

  1. 1宁夏大学农学院, 银川 750021;
    2西北退化生态系统恢复与重建教育部重点实验室, 银川 750021
  • 收稿日期:2018-09-05 出版日期:2019-06-15 发布日期:2019-06-15
  • 通讯作者: * E-mail: whm_826@163.com
  • 作者简介:赵亚楠,男,1995年生,硕士研究生. 主要从事草原生态、资源与环境研究. E-mail: nxuzyn@163.com
  • 基金资助:
    宁夏科技支撑计划项目(2015惠民计划)、国家自然科学基金项目(31860677)和宁夏高等学校一流学科建设项目(NXYLXK2017A01)资助

Soil organic carbon dynamics and the prediction of their spatial changes in response to anthropogenically introduced shrub encroachment in desert steppe of the Eastern Ningxia, China.

ZHAO Ya-nan1, DU Yan-yan1, MA Yan-ping1, ZHAO Yan-bing1, ZHOU Yu-rong1, WANG Hong-mei1,2,*   

  1. 1School of Agriculture, Ningxia University, Yinchuan 750021, China;
    2Mini-stry of Education Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwest China, Yinchuan 750021, China
  • Received:2018-09-05 Online:2019-06-15 Published:2019-06-15
  • Supported by:
    This work was supported by the Ningxia Science-technology Support Plan (the Public-Benefit Plan 2015), the National Natural Science Foundation of China (31860677), and the Ningxia Higher Education Institutions First-class Discipline Construction Project (NXYLXK2017A01)

摘要: 以宁夏荒漠草原封育草地、放牧地为对照,对不同年限(3、12、22年)和间距(2、8、40 m)柠条地开展灌丛引入对土壤有机碳(SOC)的影响研究,并模拟预测该地区人工灌丛引入过程中0~40 cm土层SOC空间特征及格局.结果表明: SOC含量随着柠条灌丛引入年限增加和间距的减小而呈增加趋势,各年限和间距柠条灌丛地SOC均值分别比放牧地高42.7%和32.8%,且均与封育草地无显著差异,但SOC的增加趋势在灌丛引入22年出现降低,降幅为27.0%.SOC空间异质性表明,研究区内人工灌丛引入后0~40 cm土层SOC含量为0.21~26.04 g·kg-1,均值为3.75 g·kg-1,变异系数为90.9%~114.7%;0~5、15~40 cm土层符合高斯模型,5~15 cm土层符合球状模型;0~5、5~15 cm土层变程均小于15~40 cm土层,三者分别为3.11、3.00和10.10 km.0~5、5~15 cm土层SOC的块金系数C0/(C0+C)为0.2%~16.3%,具有强烈的空间相关性;15~40 cm土层的块金系数为36.9%,为中等程度相关.人工灌丛引入过程中加速了退化荒漠草地0~40 cm土层SOC的累积与固定,同时加剧了土壤表层SOC空间异质性、破碎化,且与封育14年荒漠草地SOC含量无显著差异,其空间异质性、破碎化程度随土层深度增加均呈减弱趋势.

Abstract: With the 14-year enclosed grassland and the grazed grassland as control, the impacts of anthropogenic shrublands (Caragana korshinskii) with the different planting years (3, 12, 22 a) and planting spaces (2, 8, 40 m) on soil organic carbon (SOC) contents were examined in the desert steppe of Eastern Ningxia, China. We further analyzed the spatial pattern and heterogeneity of SOC in 0-40 cm soil layer of the grassland area with introduced shrubs. The results showed that SOC in C. korshinskii shrublands had an increase trend with increased planting years and decreased spaces. The mean SOC with different planting years and spaces was 42.7% and 32.8% more than that in grazing land, respectively. There was no significant difference of SOC between shrublands and the 14-year enclosed grassland. The increase trend of SOC decreased by 27.0% in 22-year planting shrubland. The SOC content of 0-40 cm soil layer varied from 0.21 g·kg-1 to 26.04 g·kg-1 (with a mean of 3.75 g·kg-1), and the coefficient of SOC variation ranged from 90.9% to 114.7%. The SOC in 0-5 cm and 15-40 cm soil layers fitted the optimal theory formulation of Gaussian model, while that in 5-15 cm soil layer fitted a spherical model. The ranges (A0) of spatial autocorrelation in the 0-5 and 5-15 cm soil layers were smaller (3.11, 3.00 km) than that in 15-40 cm soil layer (10.10 km). The nugget/sill C0/(C0+C) of SOC in 0-5, 5-15 cm soil layer was 0.2% and 16.3%, indicating a strong spatial correlation, while that in 15-40 cm soil layer was 36.9%, with a moderate correlation. The shrub introdution could significantly accelerate the accumulation and fixation of SOC in top 40 cm soil layer in degraded desert steppe, but also intensified the spatial heterogeneity and SOC fragmentation. The SOC content in the anthropogenic shrublands had no significant difference from that in the enclosed desert steppe (14 years). The SOC spatial heterogeneity and the degree of fragmentation were weakened and decreased with the increasing soil layer depth.