摘要：In order to provide theoretical basis to the C ara- gana korshinskii root system investigation work, with the C aragana korshinskii root system at the farming-pastoral ecotone of Inner Mongolia as the research object, we employ the tracking mining method to investigate the taproot diameter, average length of root systems of various diameter classes and branch number of C aragana korshinskii, and measure the rhizosphere soil water content. Based on that, we discuss the relationship between the structural features of Caragana korshinskii root system and the soil water content and taproot diameter. The results show that as the soil water content increased from 3.5-4.0% to 5.5-6.0%, the ratios of the average lengths of bone root, thick root and fine root declined from 1:0.51:0.14 to 1:0.47:0.13, and the ratios of the branch numbers of bone root, thick root and fine root increases from 1:4.43:34.94 to 1:4.60:37.13; as the taproot diameter increased from 40-50mm to 7080mm, the ratios of the average lengths of bone root, thick root and fine root declined from 1:0.44:0.13 to 1:0.41:0.11, the ratios of the branch numbers of bone root, thick root and fine root increases from 1:5:30 to 1:6:50, and both the average length of root systems of various diameter classes and branch number presented strong correlation with the soil water content. We build the relation model between the structural eigenvalues of root systems of various diameter classes and the soil water content and taproot diameter, and obtain Rlg0.99w2-39.82r2 7.12w+38.74r+7.49, RNG8.22e2-03r-4.24w+5.56, RLc23.45r2-0.17w2 -25.47r+1.40w+6.48, Rnc=52.13 (e3.53r/w L24)，RLx=1.66r-0.58In (w)+0.58 and RNx246.64e235r-178.98w+316.44 (in which, Rlg is the average length of bone root, m; Rng is the branch number of bone root, branch; Rlc is the average length of thick root, m; Rnc is the branch number of thick root, branch; Rlx is the average length of fine root, m; Rnx is the branch number of fine root, branch; r is the taproot diameter, m; w is the soil water content, %). Tests indicate that various models can w ell describe the relationship between the structural features of C aragana korshinskii root systems of various diameter classes in Huanghua Dianzi Basin and the soil water content and taproot diameter. The research results have significant importance to the planting management of artificial caragana forest in arid region, which can provide theoretical basis for the ecological environment construction and vegetation restoration in north farming-pastoral ecotone.
关键词：Caragana korshinskii;soil water content;taproot diameter;average length;branch number
