Abstract

Understanding the distribution patterns of vegetation, species richness and plant life-forms along elevational gradients can suggest important implications for developing optimal strategies for conservation of species diversity, sustainable managing and utilizing plant resources. We explored the relationships between vegetation, species richness and plant life-forms and the separate elevational gradients on the south slope and the north slope of Taibai Mountain. Eight plant communities were clearly identifiable on each slope and these communities presented zonational distributions along elevational gradients, however, the elevational ranges occupied by different communities had more overlaps at middle elevations (c. 2250 - 3350 m a.s.l.) than at two extremes. Three communities (Quences spinosa, Acer caesium subsp. giraldii and Carex capilliformis var. major communities) were first found in the area. Total species richness demonstrated a significant hump-shaped relationship with elevations on both slopes. Overall, phanerophytes, geophytes and hemicryptophytes were the most dominant life-forms, while camaephytes and therophytes were the rarest life-forms. Species richness of phanerophytes on the south slope and hemicryptophytes on both slopes exhibited a significant hump-shaped relationship with elevations, while that of therophytes on both slopes exhibited a significant reverse-hump-shaped relationship; Species richness of phanerophytes on the north slope declined with increasing elevation, however, that of chamaephytes and geophytes on both slopes increased with increasing elevations.

Key words: Elevational gradients, plant community, species richness, plant life-forms, Taibai Mountain