摘要
利用热脉冲技术,在黑河下游额济纳天然绿洲内测定胡杨单木边材液流在不同位点、方位的变化,结果表明:液流速率随深度的增加而增大,在15mm处达到最大值,随后随深度增加而减小,越靠近形成层,液流启动越早,减小滞后;在4个方位上,南、西面液流速率远远高于北、东面;南面比西面液流启动较早,下降较快;西面液流速率下降滞后于南面;在北与东面,2个方位液流速率变化不大。在此基础上,采用边材面积作为纯量,对胡杨近熟林耗水量进行了推算。胡杨林边材面积与胸径之间存在较高的相关性,两者之间的关系可以用幂模型很好地拟合。通过实测标准地的胸径分布,推算出林地边材面积的分布,利用热脉冲测定单木液流通量,推算出黑河下游胡杨近熟林年生长期(4—10月)耗水量为3172m3·hm-2。
The heat pulse technique was applied to study the variation of the stem sap flow of individual plant of Populus euphratica in different direction and depth of trunk in the Ejina oasis in the lower reaches of Heihe River. The results showed that the sap flow velocity increased with increment of depth and arrived at the maximum in 15 mm, and subsequently decreased gradually. The closer the point was to cambium, the earlier the sap flow moved. In four direction, the sap flow velocity in the south and west was more than that in the north and east; The sap flow in the south moved earlier and dropped more quickly than that in the west ; The sap flow velocity was similar in the north and east. Based on it, the water transportation of near-mature P. euphratica stand was calculated using stem area as a scalar. There was a high correlation between the stem area of P. euphratica forest and diameter by power function. So the stem area of forest could be calculated by the distribution of diameter measured in the field. The water consumption of near-mature P. euphratica forest in the lower reaches of Heihe River in the growth season from May to October was 3 172 m3·hm^-2 by measuring the sap flow flux of individual plant with heat pulse technique.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2006年第7期28-32,共5页
Scientia Silvae Sinicae
基金
国家自然科学基金项目(40501012)
中国科学院"引进杰出人才"项目(2003401)资助。
关键词
胡杨
单木液流
林分耗水量
Populus euphratica
sap flow of individual plant
forest water consumption
