Differences in growth and reproductive characters of Rosa hugonis in the dry valley of the Upper Minjiang River, Sichuan
岷江干旱河谷黄蔷薇(Rosa hugonis)生长与繁殖特征及其空间差异

The understanding of the growth and reproduction characteristics of native plants can help develop a strategy for vegetation restoration and management in a region. Rosa hugonis, a native shrub widely distributing in the dry valley of the upper Mingjiang River, appears to have great potential to rehabilitate the vegetation there because of its great ecological and economic advantages. To understand about the distribution, growth and reproduction of the plant, 20 quadrats with a interval about 10-20 km along the dry valley of the upper Minjiang River to investigate the distribution of R. hugonis, and 5 of them where the species is relatively dominant were then chosen for this study. Growth and reproductive indexes of five clumps from each quadrat were determined. Distribution, growth and reproductive characteristics of R. hugonis along the dry valley of the upper Minjiang River were analyzed. The result indicates that R. hugonis was mainly distributed in Maoxian county along the dry valley of the upper Minjiang River. The growth characteristics including height, basal diameter, mean age of ramets, crown diameter, ramet number of a clump, mean dry weight of clump, biomass and density of clump varied in different qudrats. Altitude strongly affected all the indexes except for the ramet number of a clump, and these indexes increased with rising of the quadrat altitude. The asexual-reproductive ability of the species was strong and its mean ramet number was (6.48±0.97) ramets/clump. Further, the species could sprout large number of ramets rapidly after being cut. The age structure of R. hugonis ramets trended to be pyramid model. The Fruit yield differed significantly among quadrats, and the mean setting rate was (404.96±106.91) hips/clump. There was a significant correlation between growth and fruiting parameters. The fruit number and weight of a clump was significantly affected by dry weight of clump and crown diameter. The study indicates that R. hugonis is well adapted to the environment of the dry valley of the upper Minjiang River. the species widely distributed and its growth and reproduction is favorable. So R. hugonis is recommended as a good candidate for vegetation habilitation in this region.