2种草本植物根系对长汀县崩岗洪积扇土壤水分状况的影响

发布时间：2019-04-21 08:15

【摘要】：植被恢复是防治崩岗侵蚀的重要方法,为研究植物根系对崩岗洪积扇土壤水分状况的影响,以崩岗洪积扇上种植的深根系巨菌草和浅根系宽叶雀稗为研究对象,对其分层取样后,用环刀法测定土壤的密度、孔隙度和最大持水量等物理性质,计算土壤蓄水能力,并用WinRHIZO根系分析系统,测定根长和密度等参数。结果表明:巨菌草和宽叶雀稗的各根系特征指标,均随土层深度的增加而减小,巨菌草各根系指标均大于宽叶雀稗;有植被覆盖下的土壤密度均小于裸地,植被覆盖下土壤总孔隙度和毛管孔隙度均大于裸地,且随土层深度的增加而减小;有植被根系的土壤饱和蓄水量和毛管蓄水量均比裸地高,且与裸地差异显著;在土壤表层,宽叶雀稗增加土壤孔隙性和土壤保水能力大于巨菌草,而在土壤中深层,则巨菌草大于宽叶雀稗;根系改善土壤性质的能力,主要取决于其根长密度和根系总表面积,直径小于0.5 mm的根系是影响土壤水分的最主要因子。研究植物根系对改良土壤水分状况的影响,以期为崩岗侵蚀防治中植被种类的筛选和推广提供依据。
[Abstract]:Vegetation restoration is an important method for prevention and control of landfall erosion. In order to study the effect of plant roots on soil moisture status of alluvial fan, the deep root giant fungus grass and shallow root wide paspalum planted on avalanche alluvial fan were taken as research objects. After stratified sampling, the physical properties of soil, such as soil density, porosity and maximum water holding capacity, were measured by ring knife method, and the soil water storage capacity was calculated. The root length and density parameters were measured by WinRHIZO root analysis system. The results showed that the root characteristic indexes of giant fungus grass and paspalum broad decreased with the increase of soil depth, and the root indexes of giant fungus grass were higher than that of wide paspalum. The density of soil under vegetation cover is lower than that of bare soil, and the total porosity and capillary porosity of soil under vegetation cover are higher than that of bare soil, and decrease with the increase of soil depth. The saturated water storage and capillary water storage of soil with vegetation root system were higher than that of bare soil, and the difference was significant compared with that of bare soil. In the soil surface layer, the soil porosity and water retention capacity of the broad-leaved barnyard was greater than that of the giant fungus grass, and in the deep layer of the soil, it was greater than the wide-leaved paspalum. The ability of root system to improve soil properties mainly depends on its root length density and root surface area. The root whose diameter is less than 0.5 mm is the most important factor affecting soil water content. The effects of plant roots on the improvement of soil moisture status were studied in order to provide the basis for the selection and popularization of vegetation species in the prevention and control of landfall erosion.
【作者单位】：福建农林大学资源与环境学院福建省土壤环境健康与调控重点实验室;
【基金】：国家科技支撑计划项目“中小型崩岗区的生态修复技术与示范”(2014BAD15B0303) 国家自然科学基金“花岗岩崩岗土体胶结物质与抗剪强度的关系研究”(41571272) 福建省自然科学基金“组合指纹法分析强度侵蚀小流域产沙与迁移规律”(2015J01156)
【分类号】：S157.43

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