塔里木河下游应急输水前后胡杨年轮生长差异

The Difference of analyses Populus euphratica’s tree ring growth before water transport and after water transport in the lower reaches of Tarim River

1972年塔里木河下游大西海子水库建成，下游365km河道彻底断流。为拯救沿河植被，2000年5月启动了塔里木河下游应急输水工程，迄今已经完成了7次应急输水。文章通过对塔里木河中游英巴扎和下游输水河畔英苏、喀尔达依、阿拉干断面胡杨（Populus euphratica）一级枝年轮取样调查，运用统计方法比较不同离河距离输水前后胡杨生长量差异的大小，分析了下游应急输水河畔胡杨种群对输水的响应。结果表明：1）英苏断面和喀尔达依断面在离河0～1000m输水前后胡杨生长量差异极显著。阿拉干断面在离河0～300m输水前后胡杨生长量差异极显著，离河300-700m生长量差异显著，700-1000m生长量差异不显著。由输水前后胡杨年轮生长量均值差可得，同一断面不同离河距胡杨年均生长量随离河距增大而降低。2）输水后下游3个调查断面在离河0-300m胡杨生长量增长由大到小顺序为：喀尔达依〉英苏〉阿拉干；离河300～700m由大到小顺序为：喀尔达依〉阿拉干〉英苏。3）以中游胡杨同年生长量作为参照对下游胡杨生长量进行相关比较的结果表明：应急输水前输水河畔各离河距离胡杨生长量均小于中游参照河段的生长量。应急输水后，输水河畔离河0～300m生长量已超过中游的生长量；离河300-700m输水河畔的生长量接近中游生长量；离河700～1000m生长量小于中游参照河段生长量，应急输水明显地促进了胡杨生长。

The down river 365 Ion river have completely stopped since Daxihaizi reservoir had been built in the lower reaches of Tarim River in 1972. In order to restore green corridor and improve the environment at the lower reaches of Tarim River, the project of transporting water to the lower reaches of Tarim River was carried out from May, 2000. Up to now, it has been completed seven times. In this paper, the response of Populus euphratica to implementing the project of transfusing stream water for regenerating the ecology in the lower reaches of the Tarim River is analyzed. The analysis was based on the sampling of Populus euphratica＇s tree ring in the section Yingbazha in the middle of Tarim River and the sampling of Populus euphratica＇s tree ring in the section of Yinsu,Karidayi and Alagan in the lower reaches of Tarim River. The difference of the growth of the Populus euphratica＇s tree ring of before and after water input at the different distance to Tarim River in the same year was compared by the analyses of statistics. The result shows： 1） Compared with the growth of Populus euphratica＇s tree ring before water input, from 0 to 300 m in the section of Yingsu and Kaerdayi, the water input can increase the growth of Populus euphratica＇s tree ring. From 300 m to 700 m in the section of Yingsu and Kaerdayi, the water input can increase the growth of Populus euphratica＇s tree ring. From 700 m to 1 000 m in the section of Yingsu and Kaerdayi, the water input cannot increase the growth of Populus euphratica＇s tree ring. By analyzing the growth mean remainder of Populus euphratica＇s tree ring before and after water input, the growth of Populus euphratica＇s tree ring decreased with the increase of the different distance to Tarim River in the same section. 2）The sequence of growth of 3 sections from 0 to 300 m in the distance to the lower reaches of Tarim River is Karidayi 〉 Yinsu 〉Alagan. From 300 m to 700 m, it is Karidayi 〉 Alagan 〉 Yinsu. 3 ） In order to compare to the growth of Populus euphratica＇s tree ring in the lower reaches of Tarim River, the growth of Populus euphratica＇s tree ring in the middle of reaches of Tarim River is consulted .The results show that before water input, the growth of Populus euphratica＇s tree ring is smaller than it after water input in different distance in the middle of Tarim River. From 0 to 300 m in the distance to Tarim River, the growth ofPopulus euphratica＇s tree ring is bigger than it in the middle reaches of Tarim River. From 300 m to 700 m in the distanceto Tarim River, the growth of Populus euphratica＇s tree ring is nearly the growth of Populus euphratica＇s tree ring in the middle reaches of Tarim River. From 700 m to 1 000 m in the distance to Tarim River, the growth of Populus euphratica＇s tree ring is smaller than it in the middle reaches of Tarim River. So the water input accelerated obviously the growth ofPopulus euphratica＇s tree ring.