黄土高原植被恢复对土壤物理参数的影响——基于已发表数据的荟萃分析

陆面过程在气候变化中具有重要作用,其中土壤水文过程是陆面过程的重要内容,然而目前陆面模式中土壤水力学参数仅依赖于土壤质地,并未考虑植被类型对其影响,这与自然过程不符,从而导致对大规模植被恢复的水文、气候效应认识不充分。为揭示植被恢复对土壤物理参数的影响,改进陆面模式中土壤参数的精度,论文以黄土高原为研究对象,收集整理了已发表的植被恢复下土壤物理参数的测试分析数据,从中提取了采样点经纬度、土壤质地、植被类型、恢复年限、坡度、孔隙度等信息,进行了荟萃分析。结果显示,植被恢复可促进土壤有机质的积累,明显改善土壤结构、增加土壤肥力,从而提高土壤黏粒含量,降低砂粒含量,显著提高土壤孔隙度、饱和导水率和持水能力。随着植被覆盖度的增加,这种作用也增强,恢复至林地阶段达到最高,并且阔叶林的作用要强于针叶林。随林龄增长,土壤孔隙结构和入渗性能都明显改善,土壤的持水性得到增强。研究明确了黄土高原地区植被恢复对土壤参数的影响,为更好地研究大规模植被恢复对地表水分通量的影响及其气候效应奠定了基础。

Effects of vegetation restoration on soil physical parameters on the Loess Plateau:A meta-analysis based on published data

Land surface processes play an important role in climate change. Soil hydrology process is an important part of the land surface processes. However, in the current land surface models, the parameters of soil hydrology attributes only consider soil texture, and the effect of vegetation types on soil hydrology attributes is not considered. This is inconsistent with the natural processes, and therefore the understanding on the hydrological and meteorological effects of large-scale vegetation restoration is insufficient. In order to reveal the effect of vegetation restoration on soil physical parameters and improve the accuracy of soil parameter estimations in land surface models, this study took the Loess Plateau as the research object, and collected and analyzed published test data of soil physical parameters under vegetation restoration. Information such as the latitude and longitude of the sampling site, soil texture, vegetation type, restoration period, slope, porosity, and so on were extracted for a meta-analysis. The results show that vegetation restoration can promote the accumulation of soil organic matter, significantly improve soil structure and increase soil fertility, thereby increasing soil clay content, reducing sand content, and significantly increasing soil porosity, saturated hydraulic conductivity, and water holding capacity. With the increase of vegetation coverage, these effects are also enhanced. The highest level of improvement is reached at the forestland stage, and the role of broad-leaved forest is stronger than that of coniferous forest. With the increase of forest age, soil pore structure and infiltration performance are significantly improved, and soil water holding capacity is enhanced. This study clarified the impact of vegetation restoration on soil parameters on the Loess Plateau, laying a foundation for further research on the impact of large-scale vegetation restoration on surface water flux and its climate effects.