摘要
以宁夏固原云雾山自然保护区典型草原为研究对象,采用空间序列代替时间序列的方法,以坡耕地为对照,对封育演替草地百里香（Thymus mongolicus Ronn.）、铁杆蒿（Artemisia sacrorum Ledeb.）、大针茅（Stipa grandis P.Smirn.）和本氏针茅（Stipa bungeana Trin.）群落0～10 cm表层土壤水稳性团聚体分布、孔隙度及土壤结构评价指标进行了研究和分析。结果表明：草地实施封育措施能明显改善土壤结构特征,随着草地植被自然演替,土壤的结构稳定性和孔隙状况逐步得到提高;在演替过程中,封育草地土壤的〉0.25 mm水稳性团聚体含量（WSAC）、平均重量直径（MWD）、几何平均直径（GMD）和孔隙分形维数（Dp）逐渐增加,团聚体分形维数（Da）逐渐减少,说明植被演替能促进形成良好的土壤结构;同时,土壤结构影响因素随着草地植被演替过程表现出有机碳含量显著增加,容重显著降低,毛管孔隙度逐渐增大,非毛管孔隙度逐渐降低。本研究还比较了多项土壤结构评价指标,表明与MWD和GMD相比,指标WSAC（〉0.25 mm）、Da及Dp能更好地反映出各封育草地群落之间土壤结构的差异,并与大部分影响因素具有相关关系,适宜作为该地区土壤结构的评价指标。
Enclosure managements in the semiarid steppe are expected to improve soil structures.The effects of enclosure treatment on soil structural properties were investigated using spatial sequence instead of temporal sequence method and soil samples in four enclosed sites（Thymus mongolicus Ronn.,Artemisia sacrorum Ledeb.,Stipa grandis P.Smirn.,and Stipa bungeana Trin.communities） and slope-tillage as the CK were collected from 0-10 cm depth at Yunwu Mountain,Guyuan,Ningxia Hui Autonomous Region in August 2006.Soil structural properties such as water-stable aggregates distribution,porosity,and structural parameters were determined.The results indicate that soil structural properties of enclosed plots in the semi-arid steppe were significantly promoted,and soil structural stability and pore status were gradually improved during the natural succession of vegetation.The process of natural succession gradually increased the 〉0.25 mm water-stable aggregate content（WSAC）,mean weight diameter（MWD）,geometric mean diameter（GMD）,and soil pore fractal dimension（Dp） and decreased the soil aggregate fractal dimension（Da）.Soil structure impact factors,e.g.organic carbon content and capillary porosity,increased,while the bulk density and non-capillary porosity decreased.In comparison with MWD and GMD, soil structural parameters of WSAC,Da and Dp had significant correlations with most of soil structure impact factors and could better reflect the difference of soil structural properties among different enclosed sites,so these three parameters could be suitable to evaluate soil structural properties in this area.
出处
《草地学报》
CAS
CSCD
北大核心
2009年第1期106-112,共7页
Acta Agrestia Sinica
基金
“十一五”国家科技支撑计划重大项目(2006BCA01A07)
黄土高原土壤侵蚀与旱地农业国家重点实验室基金项目(10501-152)
关键词
半干旱区
封育草地
植被演替
土壤结构特征
Semi-arid region
Enclosed steppe
Natural succession of vegetation
Soil structural property
