贡嘎山木本植物碳同位素沿海拔梯度的变化

对贡嘎山东坡不同海拔的主要木本植物稳定碳同位素的组成进行了测定。结果表明:22种木本植物叶片δ_¹³C值变化范围为-3.236%～-2.521%,平均值(-2.957±0.163)%; 不同海拔间植物叶片δ_¹³C值差异显著,随海拔上升叶片δ_¹³C值呈增加趋势; 同种植物(大叶金顶杜鹃、峨眉冷杉、水青树、箭竹)的δ_¹³C值随海拔的增加也呈相同的变化趋势。不同生活型植物叶片δ_¹³C值之间差异显著,落叶树种显著高于常绿树种。叶片δ_¹³C值与6—9月平均温度呈显著的负相关关系,与6—8月降水量呈显著的正相关关系,温度、降水是影响木本植物叶片δ_¹³C值海拔差异的主要因子。

Variations in carbon isotope of the main woody plants along the elevational gradient on the Gongga Mountain

The main woody plants were collected from different elevations on the eastern slope of Gongga Mountain to study the variety of stable isotope carbon composition along the elevational gradient. This paper showed the δ_¹³C values of 22 woody plants ranged from -3.236% to -2.521% and with the average of(-2.957±0.163)%. There was a considerable difference in the leaf δ_¹³C values of the woody plants at different elevations. The δ_¹³C values increased along the elevational gradient, and the same situation with the δ_¹³C of Rhododendron faberi, Abies fabri, Tetrcentron sinense and Fargesia spathacea. Significant difference in life form of δ_¹³C values was found, deciduous species was greater than evergreen species. Significant inverse correlation was observed between δ_¹³C values and the temperature from June to September, and a significant positive correlation between δ_¹³C values and the precipitation from June to August. The temperature and precipitation might be the main factors that influence the leaf δ_¹³C values of Gongga Mountain.