[Root architecture of main tree species and the effects on soil reinforcement in typical black soil region.]

To explore root architecture and its effects on soil reinforcement of main tree species in typical black soil region, we measured root spatial distribution characteristics, root fractal characte-ristics, and geometric morphological characteristics of Amygdalus triloba, Caragana microphylla, Betula platyphylla, Acer negundo, Picea koraiensis, Pinus sylvestris var. mongolica, using whole root excavation method and WinRHIZO Pro LA2004 root analysis system. All the examined species are distributed widely in typical black soil region. The vertical uprooting force was determined by in-situ uprooting tests. The results showed that inclined roots were dominant in A. triloba, horizontal roots were dominant in C. microphylla, B. platyphylla, A. negundo and P. koraiensis, and the horizontal and vertical distribution of roots were commensurable in P. sylvestris var. mongolica. Except for the total root surface area of B. platyphylla and the total root length of P. koraiensis, the total root length and root surface area of shrub species were significantly greater than those of arbor species, while deciduous broad-leaved trees were significantly larger than coniferous evergreen trees. The total root volume of B. platyphylla was significantly larger than that of C. microphylla, A. negundo, P. koraiensis and P. sylvestris var. mongolica. The root fractal dimension and abundance of A. triloba, C. microphylla, B. platyphylla were significantly higher than those of P. koraiensis and P. sylvestris var. mongolica. The average maximum uprooting force of A. triloba, C. microphylla, and A. negundo was significantly higher than that of B. platyphylla, P. koraiensis, and P. sylvestris var. mongolica. Due to the role of total root length, total root surface area and the number of inclined roots, root system of A. triloba, C. microphylla and A. negundo showed strong soil reinforcement capacity. A. triloba, C. microphylla and A. negundo could be used as the option-preferred tree species when constructing soil and water conservation vegetation in typical black soil region.