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	民勤绿洲二白杨树干液流的径向变化及时滞特征
其他题名	Radial variation and time lag of sap flow of Populus gansuensis in Minqin Oasis, Northwest China
	党宏忠 1; 杨文斌 1; 李卫 1; 张友焱 1; 李昌龙 2
来源期刊	应用生态学报
ISSN	1001-9332
出版年	2014
卷号	25 期号:9 页码:2501-2510
中文摘要	树木的树干液流是反映树木生理活动动态、估算单株耗水量的重要基础.本文利用热扩散技术,对民勤绿洲二白杨3株(30年生)大树树干边材各4个深度(2、3、5、8 cm)的液流速率(J)进行连续两个生长季(2011、2012)的监测.结果表明:二白杨边材液流速率最高的位点约在形成层下3 cm深处(J_3),其次依次为2、5和8 cm处(J_2、J_5和J_8),在大气蒸发潜力(ET_0)最强的6月,典型晴天日的J_3可达28.53 g·cm~(-2)·h~(-1),分别是J_2、J_5和J_8的1.42、2.74和4.4倍,径向差异明显.在日变化过程中,边材不同深处间液流速率峰值出现的时刻相差在20 min以内,但与太阳总辐射(R_s)、大气水汽压亏缺(VPD)峰值出现的时刻相差较大,在生长旺季(6-8月)的典型晴天,J的峰值滞后Rs峰值的时长(时滞)可达55~88 min,越靠近边材内侧,时滞越长.J峰值提前于VPD峰值的时长达60~96 min,越靠近边材内侧,时滞越短.液流速率的季节变化与ET_0的变化基本一致,随着树木生理活动的逐渐加强,液流传输的主要层次会向边材内部延伸.驱动不同深处液流变化的首要气象因子均为R_s,第二大因子因不同深度有所变化,越靠近内侧,代表水汽状况的因子(VPD)的重要性上升,甚至接近于R_s.
英文摘要	Sap flow of tree trunk is very important to reflect the dynamics of physiological activities, as well as to estimate the water consumption of individual plant. In the present study, we used the thermal dissipation technique to monitor the sap flow velocity (J) at four depth loci (i. e. 2 cm, 3 cm, 5 cm, 8 cm) of three Populus gansuensis trees (30 year-old) in Minqin Oasis for two consecutive growing seasons. The results showed that there were significant differences among J values at four depth loci under tree trunk cambium. J value at the 3 cm depth locus (J_3) of the tree trunk was the highest, and then in sequences, were 2 cm, 5 cm and 8 cm depth loci (J_2, J_5 and J_8). J value (J_3) on typical sunny days in June with the highest atmospheric potential evapotranspiration (ET_0) was up to 28. 53 g·cm~(-2)·h~(-1),which was 1.42, 2.74 and 4.4 times of J_2,J_5 and J_8,respectively. In the process of diurnal variation of sap flow velocity, the peak value time of J at the four depth loci of the tree trunk was different, but the differences among them were within 20 min. Furthermore, the peak value time of sap flow velocity was very different to that of solar radiation (R_s) and air vapour pressure deficit (VPD) . The time lag between J and Rs was from 55 to 88 min on typical sunny days during the main growing seasons (from June to August), and, positively related to the depth of the locus under tree trunk cambium, while the time lag between J and VPD reached 60-96 min, and was negatively related to the depth of the locus. The seasonal variation patterns of J were consistent with ET_0. With the increase of tree physiological activities, there was a trend that the major water transportation layer extended to the interior sapwood. The most important meteorological factor was the solar radiation, which primarily drove sap flow at different depths of tree trunk. However, the secondary factor changed along with the depth, and VPD became increasingly important with increasing the depth.
中文关键词	径向差异 ; 热扩散技术 ; 大气蒸发潜力 ; 日变化格局
英文关键词	radial difference thermal dissipation probe atmospheric potential evapotranspiration diurnal pattern
语种	中文
国家	中国
收录类别	CSCD
WOS类目	FORESTRY
WOS研究方向	Forestry
CSCD记录号	CSCD:5235992
来源机构	甘肃省治沙研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/231990
作者单位	1.中国林业科学研究院荒漠化研究所, 北京 100091, 中国; 2.甘肃省治沙研究所, 兰州, 甘肃 730070, 中国
推荐引用方式 GB/T 7714	党宏忠,杨文斌,李卫,等. 民勤绿洲二白杨树干液流的径向变化及时滞特征[J]. 甘肃省治沙研究所,2014,25(9):2501-2510.
APA	党宏忠,杨文斌,李卫,张友焱,&李昌龙.(2014).民勤绿洲二白杨树干液流的径向变化及时滞特征.应用生态学报,25(9),2501-2510.
MLA	党宏忠,et al."民勤绿洲二白杨树干液流的径向变化及时滞特征".应用生态学报 25.9(2014):2501-2510.