黄土丘陵区退耕坡面草地恢复与土壤物理性质空间分异特征

为了解地形对草地恢复与土壤物理性质的影响以及草地恢复与土壤物理性质之间的影响机制,因地制宜为当地生态恢复提供科学依据。选择吴起县枣庄沟小流域为研究区,对退耕坡面不同坡位草地恢复与土壤物理性质分异特征进行研究。从峁顶到沟底设置8个采样位置,在4面坡共布设128个采样点进行植被调查和土样采集,将0—40 cm土壤分0—10,10—20,20—40 cm 3层进行土壤物理性质测定,并分析其与植被分布的相关关系。结果表明:不同坡位植被分布与土壤物理性质均表现出沟缘线以上的下坡位较优,沟缘线以下的陡沟坡较差的趋势;植被恢复对土壤团聚体有明显改善作用,但对其与土壤物理性质的改善主要集中在0—20 cm表层土壤,对20—40 cm土壤影响较弱;坡度对植被盖度与土壤容重、孔隙度和饱和持水量影响显著且具有极显著相关性,但对团聚体与颗粒组成无显著影响;植被恢复对土壤颗粒组成改善效果缓慢,若土壤颗粒组成被破坏,短期内很难恢复。

Spatial Differentiation Characteristics of Grassland Restoration and Soil Physical Properties of Slope in Hilly-gully Region of Loess Plateau

In order to understand the effect of microtopography on vegetation restoration and soil physical properties,exploring the influence mechanism between grassland restoration and soil physical properties and to provide scientific basis for local ecological restoration.This study choose the Zaozhuanggou basin in Wuqi county as the study area,vegetation restoration and soil physical properties differentiation characteristics on the different landscape positions were studied.We chose 4 slopes and set eight sampling positions on every slope from top to bottom,a total of 128 sampling points of vegetation investigation and soil samples collected in this study.The soil was divided into three layers 0—10,10—20 and 20—40 cm for sampling and determining soil physical properties,analyzed the correlation between vegetation distribution and soil physical properties.The results showed that the vegetation distribution and soil physical properties on different landscape positions showed the tendency of lower slope better than others above the groove line,and the bottom slope is worst.The vegetation restoration has improvement effect on soil aggregate,the improvement of soil aggregate and soil physical properties caused by vegetation restoration was mainly concentrated on the surface soil of 0—20 cm,and weak in the soil of 20—40 cm.Gradient has a significant impact on vegetation coverage,soil bulk density,porocity and saturated water capacity.But it has no significant effect on the soil aggregate and soil particle composition.The effect of vegetation restoration on improving soil particle composition is slow.If the soil particle composition is destroyed,it will be difficult to recover in the short term.