石灰岩山地坡位对侧柏光合蒸腾特性的影响  

Slope positions effects on photosynthesis and transpiration characteristics of Platycladus orientalis in limestone mountain

作　　者：蒋丹丹[1] 万福绪[1] 黄文庆[1] 

机构地区：[1]南京林业大学林学院,南京210037

出　　处：《林业科技开发》2014年第6期59-63,共5页China Forestry Science and Technology

基　　金：江苏省林业三新工程(013010247);江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：为分析困难山地不同坡位侧柏光合和蒸腾作用等生理特性的差异,利用Li-6400便携式光合仪对石灰岩山地4种坡位侧柏的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、光合有效辐射(rPAR)、空气相对湿度(Hr)、气温(Ta)等指标进行测定。结果表明:不同坡位侧柏净光合速率最大值均出现在8:00,底坡和中坡侧柏在中午都出现午休现象;坡位越高,侧柏日均净光合速率越低。各样地侧柏蒸腾速率日变化均呈双峰曲线,日均蒸腾速率由大到小依次为顶坡>平地>中坡>底坡。底坡侧柏气孔导度在中午时值最小,且日均水分利用效率最高。相关性分析表明,研究区侧柏光合蒸腾作用的主要影响因子是气孔导度、光合有效辐射和空气相对湿度,底坡是最适合侧柏生长的位置。In order to analyze photosynthesis,transpiration and other physiological characteristics of Platycladus orientalis at different slope positions in limestone mountain,net photosynthetic rate（ Pn）,transpiration rate（ Tr）,stomatal conductance（ Gs）,photosynthetic active radiation（ rPAR）,relative humidity（ Hr）,airtemperature（ Ta） of P. orientalis were measured with a Li-6400 portable photosynthetic equipment. The results showed that the net photosynthetic rates of P.orientalis in different slope positions reached the maximum value at 8 ∶ 00 am and appeared obviously phenomenon of noon break in the midday. Higher the slope position was,lower the daily average net photosynthetic rate was. The transpiration rate of P. orientalis had a changing course daily in double peaked,average diurnal value of which was ordered by uphill 〉flat 〉 middle slope 〉 downhill. P. orientalisin at downhill presented the least stomatal conductance value and the highest average diurnal water use efficiency value. Correlation analysis indicated that the most important effective factors on photosynthetic rate and transpiration rate were Gs,rPARand Hr,which required to use sprinkler irrigation in arid season to improve air humidity. And the downhill was the most suitable location for P. orientalis to grow.

关 键 词：侧柏 净光合速率 蒸腾速率 水分利用效率 石灰岩山地 

分 类 号：S791.254[农业科学—林木遗传育种]