Abstract:

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.