元谋干热河谷一种景观树种羊蹄甲的光合特性研究

Study on the Photosynthetic Characteristics of Bauhinia blakeana—A Kind of Landscape Trees in Yuanmou Dry-Hot Valleys

摘要: 通过对羊蹄甲的光合速率、气孔导度及其相应环境因子的测定，探讨元谋干热河谷羊蹄甲的光合生理生态特征。本研究采用TPS-1 (英国PPsystems公司出品)便携式光合测定系统对元谋县县城绿化树羊蹄甲的光合特性进行了研究，结果表明：羊蹄甲净光合速率的日变化成双峰曲线，光照强度(PAR)、蒸腾速率(Tr)、胞间CO₂浓度(CI)、大气CO₂浓度(Ca)、气孔导度(GS)、温度(T)等因子都会影响羊蹄甲的净光合速率，羊蹄甲对光能的利用率平均值为0.03 mmol∙mol⁻¹，对水分的利用率平均为2.061 mmol∙mol⁻¹。羊蹄甲在元谋干热河谷有较强的适应性。

Abstract: In order to study the photosynthetic characteristics of Bauhinia blakeana, the photosynthetic rate, stomatal conductance and its corresponding environmental factors were measured. Photosynthetic characteristics of Bauhinia blakeana, a kind of greening tree species in Yuanmou County, were measured by using TPS-1 portable photosynthetic measurement system (produced by PPsystems Company in the British). The results showed that the daily variation of net photosynthetic rate of Bauhinia blakeana showed bimodal curve. The factors of photosynthetic active radiation (PAR), transpiration rate (Tr), intercellular CO₂ concentration (Ci), atmospheric CO₂ concentration (Ca), stomatal conductance (Gs) and temperature (T) impacted on the net photosynthetic rate of Bauhinia blakeana. The average value of light use efficiency was 0.03 mmol∙mol⁻¹, and water use efficiency was 2.061 mmol∙mol⁻¹. Bauhinia blakeana had stronger adaptation in Yuanmou dry-hot valleys.