岷江干旱河谷黄蔷薇(Rosa hugonis)生长与繁殖特征及其空间差异

对乡土植物生长繁殖特征的认识是制定合理的植被恢复及管理措施的基础和依据.通过大面积的野外踏查和样方调查,分析了岷江干旱河谷乡土灌木-黄蔷薇(Rosa hugonis)的分布、生长繁殖特征及空间差异.发现:(1)黄蔷薇主要分布于岷江干旱河谷的茂县段,其植株株高、基径、年龄、丛冠幅、丛的萌生数、丛干重、丛生物量和密度等生长特征存在明显空间差异,除丛萌生数和密度之外海拔对其他各参数都有较大的影响,这些参数的值在高海拔地段大于低海拔地段;(2)黄蔷薇在干旱河谷丛平均萌生数为6.48±0.97株/丛,丛的萌生能力较强,且其受砍伐后具有很强的再生能力;萌生株年龄结构大致为金字塔型,最大植株年龄为25a;(3)干旱河谷黄蔷薇的结实量较大,平均值为(404.96±106.91)果/丛,结实特征表现出明显的空间差异性;(4)各生长与结实参数关系密切,影响结实量的最主要的生长因素是冠幅和丛干重.研究结果表明:黄蔷薇适应干旱河谷的环境条件,具有较广泛的分布,生长和和繁殖状况良好,是可供选择的干旱河谷恢复物种.

Differences in growth and reproductive characters of Rosa hugonis in the dry valley of Upper Minjiang River, Sichuan

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.