Abstract:Understanding the geographic variation of the growth and reproduction characteristics of native plants may help to develop effective strategies for vegetation restoration in degraded regions. Rosa soulieana, a native shrub widely distributing in the dry valleys of the Hengduan Mountain region, appears to have a great potential to rehabilitate the vegetation because of its ecological and economic advantages. To determine the distribution, growth and reproduction of this species, 18 plots were investigated along the dry valleys of four rivers (Minjiang, Daduhe, Yalongjiang and Jinshajiang) in June and October 2011. Eight location parameters of each plot were recorded including drainage, latitude, longitude, altitude, slope gradient, slope aspect, position, and height from river. Ten clumps were randomly selected for measuring the growth parameter, and five clumps for reproductive parameters in each plot. Soil parameters were measured using samples collected from the five clumps that had been used to record reproductive parameters. The results indicated that R. soulieana was widely distributed in each dry valley of Hengduan Mountain region at altitudes from 1,700 to 3,700 m above sea level. Mean plant height was (2.64 ± 0.17) m, which was higher than that of other species in the community in the dry valley region. PCA and correlation analyses showed that location (drainage, latitude, longitude, and altitude) and soil traits (total carbon, total organic carbon, total nitrogen, and pH) were the principal factors influencing growth and reproduction, and location had a stronger influence than that of soil traits. Growth traits (height, base diameter, and crown diameter) differed significantly among the 18 populations, but not among drainages. Vegetative reproduction was high with a mean of (2.5 ± 1.9) ramets per individual, with a maximum of 25 ramets on a single individual. Ramet number per individual differed less among the populations than growth traits, but it was significantly different among drainages. R. soulieana also exhibited strong sexual reproduction. Seed vitality of 83.3% of the populations was > 80%. The reproductive parameters exhibited stronger spatial variation than growth traits. Fruit mass, achene mass, and seed vitality were highly significantly different among the 18 populations, but only fruit mass and seed vitality were significantly different among the four drainages. Fruit mass was significantly greater in the Yalongjiang drainage than in the other three. Seed vitality was greater in Minjiang and Jinshajiang drainages than in the Yalongjiang and Daduhe drainages. Comprehensive analysis showed pronounced geographic variation in growth and reproduction in R. soulieana in the dry valleys of the Hengduan Mountain region. Strong vegetative reproduction ensures the persistence of the populations, and sexual reproduction provides genetic material for this species to adapt to the environment and expand their distribution in dry valleys.