Study of Drought Resistance of Thirteen Sand-Fixing Plants in Horqin Sand Land, China

摘要

The Horqin Sand Land is characterized by a continental semi-arid monsoon climate. Water is a key limiting factor for the restoration of vegetation and ecological construction in this area. Selecting species with high levels of drought resistance for the restoration of vegetation in this area is important. Thirteen sand-fixation plants species in this region (Caragana korshinskii, C. microphylla, Elaeagnus angustifolia, Euonymus bungeanus, Hedysarum fruticosum, Hippophae rhamnoides, Picea mongolica, Pinus sylvestris var. mongolica, Sabina vulgaris, Salix gordejevii, S. matsudana, Ulmus pumila, and Xanthoceras sorbifolia) were selected and seven drought resistance indexes (water saturation deficit, specific leaf area, leaf water-retaining capacity, chlorophyll content, foliar δ13C value, leaf water potential, and leaf transpiration rate) were measured. The comprehensive evaluation of the thirteen species generated the following rank order as S. vulgaris>P. mongolica>P. sylvestris var. mongolica>H. rhamnoides>E. angustifolia>C. microphylla>S. gordejevii>X. sorbifolia>C. korshinskii>S. matsudana> E. bungeanus>U. pumila> H. fruticosum in terms of drought resistance through subordinate function values analysis. Using the group mean cluster analysis method, the thirteen plant species fall into three groups and the rank order of the capacity for drought resistance from the highest to the lowest was as follows: (1) S. vulgaris, P. mongolica, and P. sylvestris; (2) H. rhamnoides, E. angustifolia, C. microphylla, S. gordejevii, X. sorbifolia, C. korshinskii, S. matsudana, E. bungeanus, and U. pumila; and (3) H. fruticosum. Among the seven drought resistance indexes, specific leaf area was the most effective. The results have important implications for the establishment of artificial plantations in Horqin sand land and other semi-arid sand land areas in China.