Altitude distribution pattern of species diversity in tropical natural forest in Diaoluo Mountain

Abstract

Altitude is the key factor affecting species diversity pattern. In order to explore the altitude distribution pattern of species diversity in tropical natural forest in Diaoluo Mountain, vegetation survey was conducted in six tropical natural forest plots from 245 to 1 130 m. The species diversity and community characteristics of tropical natural forest along the altitude of Diaoluo Mountain were analyzed from the aspects of species composition, species diversity, flora composition and leaf characteristics. The results were as follows: (1)With the increase of altitude, the temperature decreased, the humidity increased and the human disturbance decreased. The species composition of tropical natural forest in Diaoluo Mountain and the diversity indexes of Margalef, Shannon-Wiener, Simpson, and Pielou all showed a pattern of first increase and then decrease. The middle-altitude community had the most suitable hydrothermal conditions and moderate human disturbance, and the α species diversity was the highest. (2)With the increase of altitude, the proportion of important value (IV) of dominant species decreased first and then increased, and the dominant species had obvious replacement phenomenon. The middle altitude community showed the transition nature of lowland rain forest and mountain rain forest. (3) The Sørensen community similarity coefficient between communities was significantly negatively correlated with altitude difference (P0.05). To sum up, the hydrothermal conditions and human disturbance degree of low altitude community in Diaoluo Mountain are quite different from those of high altitude community, which leads to the difference of species distribution and community characteristics, and reflects the characteristics of tropical plants adapting to their habitat conditions.

Keywords

• altitude
• tropical natural forest
• species composition
• species diversity
• flora
• leaf characteristics