遂渝铁路边坡草本植物多样性季节动态和空间分布特征

以遂渝铁路边坡植物群落为研究对象，自然边坡为对照，分别于2008年9月、12月、2009年3月和6月对其进行植物调查。采用Margalef指数、Simpson指数、Shannon-Wiener指数和Pielou指数等指标评价不同季节、坡位和植被类型条件下草本植物多样性的变化。结果表明：在时间尺度上，铁路边坡坡中物种丰富度呈现明显的季节性差异(P<0.05)，以秋季最大为2376；铁路边坡各坡位草本植物多样性和均匀度指数也呈现显著季节性变化(P<0.05)，且变化规律一致：春季>夏季>冬季>秋季；与铁路边坡不同，自然边坡草本植物丰富度、多样性和均匀度指数变化趋势不明显(P>0.05)。在空间分布上，坡位对铁路边坡物种丰富度影响显著(P<0.05)，其中，夏季坡上植物丰富度最大为2.164，春季、秋季和冬季丰富度最大值均在坡中最大，分别为2.261、2.376和1.983；坡位仅对自然边坡秋季物种丰富度和均匀度影响显著(P<0.05)，其中，物种丰富度表现为坡上>坡下>坡中，而均匀度为坡中>坡上>坡下。不同植被类型的物种丰富度、多样性和均匀度也有较大差异，自然边坡物种多样性明显大于铁路边坡，总体上自然边坡植被恢复优于铁路边坡。因此，加强对植被恢复的管理是铁路边坡生态恢复的重要环节。

Seasonal dynamics and spatial distribution of herbage diversity on the slopes of Suiyu railway

Seasonal dynamics and spatial distribution of herbage diversity were studied in the vegetation on the slopes of Suiyu railway as compared with the natural slopes. Herbaceous community was investigated in four seasons including March (spring), June (summer), September (autumn) and December (winter) from 2008 to 2009, respectively. The Margalef index, Simpson index, Shannon-Wiener index and Pielou index were analyzed. The results indicated that, the species richness existed prominent difference in the middle slope on the slopes of Suiyu railway (P<0.05), the maximum species richness reached 2.376 in autumn. Both species diversity and evenness index had significant difference among different seasons in different location of the slope (P<0.05), and the changing of species diversity and evenness index had the same rules with the following order: spring > summer > winter > autumn, while the seasonal changes of species richness, diversity and evenness indices were not obvious on the natural slope. The location of the railway slope affected the species richness prominently (P<0.05) rather than diversity and evenness (P>0.05), the species richness reached its maximum of 2.164 in summer on the upper slop, 2.261, 2.376 and 1.983 in spring, autumn and winter on the middle slop respectively. The location of the natural slope only affected the species richness and evenness in autumn significantly (P<0.05), moreover, they had different kinds of changing rules. The species richness followed the order as of upper > lower > middle, whereas, the evenness followed the order as of middle > upper > lower. There existed larger differences in the aspect of the species richness, diversity and evenness among different vegetation types. The species richness on the natural slope was significantly larger than that on the railway slope, and the vegetation restoration on the natural slope was better than that on the slope of railway. So strengthen the management is key measurement to ecological restoration of railway slope.