CAJ | 학술논문

生长在塔里木河流域的荒漠河岸林植被虽长期忍受着高温和干旱的威胁,然而它们却能够一直延续并保存至今.除了植物深根系吸水作用外,另一个更主要的原因可能就是荒漠河岸林植被存在水力提升的效应.该文采甩HRM热比率法茎流仪对3株胡杨(Populus euphratica)主根和侧根的液流速率分别进行了为期4 d的连续监测:利用自动气象站对微气象因子:风速、空气相对湿度、叶面温度和地表温度进行连续监测;同时采用了烘干法对不同深度土层在不同时刻的土壤含水率进行了取样分析.试验结果表明:胡杨主根液流在白天和夜间均表现为正值,相反的,胡杨侧根液流速率则出现了明显的夜间负向流动.胡杨根系0～120 cm土层土壤水分含量具有下湿上千的变化趋势;胡杨侧根在夜间发生负向流动后,土壤含水率显著升高,尤其在60～120 cm土层中,4:00土壤含水率上升幅度达到4:00时刻土壤含水率的22%～26%.影响胡杨侧根液流速率的主要气象因子主要是叶面水汽压亏缺.
생장재탑리목하류역적황막하안림식피수장기인수착고온화간한적위협,연이타문각능구일직연속병보존지금.제료식물심근계흡수작용외,령일개경주요적원인가능취시황막하안림식피존재수력제승적효응.해문채솔HRM열비솔법경류의대3주호양(Populus euphratica)주근화측근적액류속솔분별진행료위기4 d적련속감측:이용자동기상참대미기상인자:풍속、공기상대습도、협면온도화지표온도진행련속감측;동시채용료홍간법대불동심도토층재불동시각적토양함수솔진행료취양분석.시험결과표명:호양주근액류재백천화야간균표현위정치,상반적,호양측근액류속솔칙출현료명현적야간부향류동.호양근계0～120 cm토층토양수분함량구유하습상천적변화추세;호양측근재야간발생부향류동후,토양함수솔현저승고,우기재60～120 cm토층중,4:00토양함수솔상승폭도체도4:00시각토양함수솔적22%～26%.영향호양측근액류속솔적주요기상인자주요시협면수기압우결.
Aims In the Tarim River Basin of China, desert riparian forest vegetation grows despite the stresses of high temperature and aridity. The species have deep roots that absorb soil water, but a more important reason may be the hydraulic lift (HL) of species. Our aims are to explore whether HL exists in desert riparian vegetation and to determine its ecological impacts.Methods We studied the HL of Populus euphratica, an important species of desert riparian forest, in September 2008. We used heat ration method (HRM) sap-flow monitoring sensors to measure sap velocity in roots of three trees during four days. Meteorological factors, including wind speed, air relative humidity, leaf temperature and surface temperature, were monitored by a recording weather station. We concurrently sampled and analyzed soil water content by the drying method at six soil depths. Important findings The sap velocity of tap roots was positive day and night. In contrast, sap flows of lateral roots reversed at night. Soil water content in the subsoil was higher than topsoil in 0-120 cm soil depth and increased with reversed sap flow of lateral roots at night, especially in the 60-120 cm soil depth (soil water content was 28%-38% greater at 4:00 than that at 16:00. Leaf surface vapor pressure deficit can critically affect sap velocity in lateral roots. Hydraulic redistribution has commonly been associated with arid or strongly seasonal environments; our findings prove it also occurs in an extremely arid region of middle Asia.