生态输水干扰下塔里木河下游阿拉干断面幼龄胡杨树高变化分析

Analysis on the Tree Height Change of Juvenile Populus euphratica in the Lower Reaches of Tarim River under effects of Ecological Water Conveyance

[目的]评估塔里木河下游10次应急输水对荒漠河岸林的效益程度。[方法]根据近5年在塔河下游阿拉干断面河道两岸设立的胡杨长势指标数据,对比河道附近区域内幼龄胡杨树高增长量的变化。[结果]应急输水后河道两边地下水位抬升,对离河道距离近区内幼龄胡杨树高增长有了一定的促进作用,2005年,距离河道50 m以内幼龄胡杨平均树高为2.02 m,到2010年增至2.66 m;距离河道50 m以内幼龄胡杨树高增长量与离河道距离之间的相关性显著,相关系数R2为0.362 8;虽然应急输水量不断增加,但幼龄胡杨树高年增长量呈下降的趋势。[结论]该研究为塔里木河下游荒漠河岸林的恢复提供了理论依据。

[Objective] The study aimed to assess the efficiency of 10 times of emergency water conveyance to the lower reaches of Tarim River.[Method] Based on the tree vitality data of P.euphratica in the long term monitoring sample plot at Arghan section,tree height growth quantity of juvenile P.euphratica in near distance area was compared.[Result] As the result of emergency water conveyance,rising groundwater level played important role in tree growth change of juvenile P.euphratica.In 2005,average tree height of juvenile P.euphratica in 50 m distance from the river area was 2.02 m,while it changed to 2.66 m in 2010.The correlation coefficient between P.euphratica tree height growth and distance from the river was 0.362 8.Although water quantity being conveyed increased,annual tree height growth of juvenile P.euphratica decreased.[Conclusion] The study can provide theoretical basis for restoration of forest in the lower reaches of Tarim River.