三江源区植物根-土复合体的抗拉拔力特征及影响因素分析

Tensile Resistance Characteristics of Root-Soil Composite System and Influence Factor Analysis in Sanjiangyuan Regions of Qinghai-Tibet Plateau

为研究高寒地区草地恢复过程中牧草根系固土稳定性机制,在青藏高原三江源区对燕麦根—土复合体进行原位拉拔试验,系统分析了燕麦根—土复合体抗拉力的表现特征及影响因素。结果表明:(1)根—土复合体的抗拉力在不同地形、种植方式等不同情况下,表现出的特征不一致。高密度区比低密度区的抗拉力小,撒播区比条播区的抗拉力小,高坡度区比低坡度区抗拉力小,远离冲蚀沟区比冲蚀沟区附近抗拉力小,且差异显著(P<0.05)。(2)根—土复合体的抗拉力与地上生物学性状相关性低,与根系生物学性状相关性高。(3)复合体的抗拉力与根径(RD)、须根条数(RN)呈极显著正相关(P<0.01),与根长(RL)、单根生物量(RW)呈显著正相关(P<0.05)。

To study the stability mechanism of the root-soil complex in restored alpine meadow,the tests for the tensile resistance of plant roots were carried out in Sanjiangyuan Regions of Qinghai—Tibet Plateau.The performance characteristics of the root tensile resistance and factors affecting root-soil complex were analyzed.All the results showed that:(1)the root-soil complex showed different characteristics under the conditions of different terrain and different planting way,the root tensile resistance in the area with high density of oats is smaller than that in the area with low density of oats,sowing ways affected the root tensile resistance,the root tensile resistance in the area with drilling sowing way is smaller than that in the area with scattering sowing way,slopes affect the root tensile resistance,the root tensile resistance in the area with greater slopes is smaller than that in the area with less slopes,in addition,the distances from the planting sites to the erosive ditches also affect the root tensile resistance,the root tensile resistance in the areas far away from the erosive ditches is significantly less than that in the area near the erosive ditches(P<0.05);(2)the correlation between root tensile resistance and the biological characteristics of the ground-above parts of oat plants was low,but is high between root tensile resistance and the biological characteristics of the ground-below parts of oat plants;(3)there are significant positive correlations with root diameters(RD),root numbers((RN),root length(RL),the biomass of single roots(RW)(P<0.05).