黄土半干旱区土壤水分对侧柏叶片水气交换影响  

Influence of Soil Moisture on Exchange between Water and Gas of Oriental Arborvitae at Semi-Arid Region of Loess Plateau

作　　者：郭江红[1] 王百田[1] 田晶会[1] 

机构地区：[1]北京林业大学水土保持学院,北京100083

出　　处：《水土保持学报》2004年第2期157-160,165,共5页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(3007063);国家攻关项目(2001BA510B0304)资助

摘　　要：2002年4～10月,在山西省方山县径流林业试验基地,通过水分控制措施形成土壤水分梯度,对野外栽植的侧柏叶片进行了蒸腾、光合及环境因素的观测。结果表明:侧柏叶片的蒸腾速率与土壤含水量有密切的关系,随着土壤含水量的降低水分胁迫加剧,蒸腾速率显著降低,而且一般受到水分胁迫的树体在低光照条件下出现蒸腾的峰值,随着光照与气温的增加蒸腾速率下降,水分胁迫程度越严重蒸腾峰值出现的时间越早。当土壤含水量没有造成水分胁迫时,侧柏叶片的蒸腾速率日变化与光照及气温的变化相一致。试验条件下,春季土壤含水量在5.79%以下时产生了严重的水分胁迫,土壤含水量达到6.50%时相对水分胁迫较轻;夏季土壤水分在6.94%以下时产生严重水分胁迫;秋季没有产生水分胁迫,但是仍然是土壤含水量较高时蒸腾速率也较高,这为黄土高原地区布设相应的径流林业措施,进行有效的土壤水分管理提供了依据。By means of artificial control four gradients of soil water content (SWC) were established under natural condition, transpiration rate(Tr) and net photosynthesis rate(Pn) and environmental factors of Oriental Arborvitae were measured in runoff forestry research station at Fangshan county of Shanxi province from April to October in 2002. The results show that Tr has a close relation with SWC. It significantly decreases with decline of SWC, and the severer soil water stress, the earlier time of peak of Pn. As the SWC do not induces soil water stress, the diurnal changes of Tr accord with the diurnal change of radiation intensity and temperature. Under the situation of this research, the water stress of Oriental Arborviate appeared as the SWC was below 5.79%, and it became smaller when the SWC approached to 6.50% in spring, while it was very severe below 6.94% SWC in summer, no water stress was observed in autumn but Tr still changed according to SWC. This result provides evidence for measurements of runoff forestry and its effective management on the soil moisture.

关 键 词：黄土半干旱区 土壤水分 侧柏 叶片 水气交换 

分 类 号：S152.7[农业科学—土壤学] S791.38[农业科学—农业基础科学]