冰雪灾害后堇菜属植物多样性及其垂直分布规律

为了揭示冰雪灾害对堇菜属植物多样性和垂直分布规律的影响，采用线路调查结合样带的调查方法，将杨东山十二度水自然保护区分为350~600 m、600~800 m、800~1000 m、1000~1200 m、1200~1400 m等5个连续的海拔段，对堇菜属冰灾后的植物多样性和分布规律进行调查分析，并与灾害前黎昌汉等的研究成果进行对比分析。结果表明：随海拔的升高，各海拔段堇菜属植物分别为7、12、12、8、3种，物种多样性呈“钟型”曲线，具有良好光照、水热条件的中海拔段600~1000 m的多样性最高；堇菜属各植物的生境要求不同，各海拔段种类组成差异显著，相邻海拔段的相似性系数高，海拔段相隔越远，相似性系数越低；堇菜属植物多度随海拔的升高同样呈“钟型”曲线，600~800 m海拔段多度最高；冰灾前后结果对比表明，冰雪灾害对堇菜属垂直分布格局的总体趋势并无太大影响，均为“中间膨胀型”或“单峰型”，在一定程度上说明宿根草本植物具有较强的抗冰灾能力。

The Characteristics of Plant Diversity and Vertical Distribution Pattern of Viola L. After Ice-disaster

In order to exposit the influence of ice-disaster on the plant diversity and the vertical distribution pattern of Viola L., which were investigated and analyzed at 5 different altitudinal gradients from 350 m to 1400 m in Yangdongshan Shierdushui nature reserve after ice-disaster by the sample line and strip method. And the contrastive analysis was carried on between these data and the results of Li Changhan, etc. in 2005 before ice-disaster. The results showed that: the number of Viola species was in the order of 7, 12, 12, 8 and 3 from low altitude to high with approximately 200 m for each gradient. The change trend of species richness of Viola was ‘clock’ type curve. More species abundance appeared at elevation of 600-1000 m, in which it had good illumination and hydrothermal condition. Because the difference of Viola plants habitat was remarkable, species composition was significantly different among the altitudinal gradients. The nearer the height, the greater the similarity coefficient was. Compared before and after ice-disaster, the plant diversity and vertical distribution pattern of Viola L. was the characteristic of ‘the inverse correlation’ and ‘the middle inflation’. It could draw the conclusion that ice-disaster had no effect on the plant diversity and vertical distribution pattern of Viola, and that the persistent root herbs had strong ability of resisting ice disaster on certain degree.