科尔沁沙地樟子松人工林土壤水分动态及其对降雨的响应

• 作者： 吉吉佳门 ^1,2 程一本 ¹ 谌玲珑 ¹ 万鹏翔 ¹ 张祎晖 ¹ 杨文斌 ² 白旭赢 ¹ 王 涛 ³
• 作者单位：
  1.  北京林业大学水土保持学院，北京100083

  2.  中国林业科学研究院荒漠化研究所，北京 100091

  3.  内蒙古低覆盖治沙科技开发有限公司，内蒙古 呼和浩特 010010
• 提交时间：2023-05-30

摘要: 在科尔沁沙地采用两行一带种植模式低密度栽培樟子松进行生态修复后，林地土壤水分动态及其对降雨的响应影响了同类型地区是否可以持续使用樟子松进行生态修复。为了研究科尔沁沙地南缘植被修复后土壤水分动态特征，本研究综合运用原位观测、数值模拟的方法，基于土壤水分实测数据校正Hydrus-1D模型，探究降雨-土壤水分响应关系。结果表明：（1）樟子松人工林显著改变了地区水分分布，裸沙地2.0 m处深层渗漏量占降雨量的44.16%，而樟子松林地深层渗漏量仅占降雨量的0.7%。（2）监测期内，0.4 m深度以下土壤水分对小雨无响应，土壤水分对中雨的响应深度可达1.0 m，对大雨和暴雨的响应深度涉及整个观测剖面。随着土壤深度的增加，水分波动幅度呈现减小的趋势。（3）降雨量和深度较浅的土壤体积含水量之间存在较强的相关关系，周期为周、半月的累计降雨量与各层土壤体积含水量显著相关；降雨量大于50 mm时，能保证对2.0 m处土壤水分的补给。（4）模型的决定系数范围在0.61~0.85，均方根误差范围在0.0061~0.0096 cm3cm-3，能较好地模拟研究区土壤水分的动态变化特征，且深层模拟精度高于浅层。研究结果对科尔沁沙地雨养型植被造林、生态恢复和水资源管理具有重要的意义。

Abstract: After ecological restoration in Horqin Sandy Land, the soil moisture dynamics of the forest and its response to rainfall affect whether Pinus sylvestris var. mongolica(PSM) can be continuously used for the ecological restoration in the same type of area. To study the characteristics of soil moisture dynamics after vegetation restoration on the southern edge of Horqin Sandy Land, this study used the methods of in situ observation and numerical simulation and corrected the HYDRUS-1D model based on the measured data of soil moisture to explore its relationship with rainfall. We obtained the following results: (1) The regional moisture distribution was changed by the PSM plantation, deep soil recharge at 2.0 m in bare sand accounted for 44.16% of the annual rainfall, whereas deep soil recharge at 2.0 m in PSM land accounted for only 0.7% of the annual rainfall. (2) Soil moisture below a depth of 0.4 m had no response to light rain, but the response depth of soil moisture to moderate rain could reach 1.0 m. The response depth to heavy rain and rainstorm involved the entire observation profile. With increasing soil depth, a decreasing trend was observed in the variation in moisture fluctuation. (3) There was a strong correlation between rainfall and volumetric soil water content at shallow depth, and the cumulative rainfall at weekly and semi- monthly intervals was significantly correlated with the volumetric soil water content of each layer(P50 mm can ensure the supply of soil moisture within 2.0 m. (4) The determination coefficient of the model was between 0.61 and 0.85, and the root mean square error ranged from 0.0061 to 0.0096 cm -3cm -3. The accuracy of the deep layer simulation was higher than that of the shallow layer. These results have important implications for rain- fed vegetation afforestation in the Horqin Sandy Land.

• 分类： 农、林、牧、渔 >> 土壤学
• 引用： ChinaXiv:202305.00249 (或此版本 ChinaXiv:202305.00249V1)
  doi:10.12074/202305.00249
  CSTR:32003.36.ChinaXiv.202305.00249.V1
• 推荐引用方式： 吉吉佳门,程一本,谌玲珑,万鹏翔,张祎晖,杨文斌,白旭赢,王 涛.(2023).科尔沁沙地樟子松人工林土壤水分动态及其对降雨的响应.干旱区研究.[ChinaXiv:202305.00249] (点此复制)