不同更新方式下胡杨幼苗光响应和CO2响应的对比研究

Comparative study on light response and CO2 response of Populus euphratica seedlings under different regeneration methods

分析人工挖坑和天然落种更新方式下不同苗龄胡杨光合作用参数在速生期(6月、7月、8月)的变化差异,以期选择适宜的植苗更新方式,为塔里木河下游胡杨林更新复壮提供依据.研究采用美国Li-6400XT光合仪测定了2年、3年、5年和7年生胡杨苗在速生期的光合作用-光和CO2响应.结果表明,人工挖坑更新方式下的胡杨苗光合潜力较好,尤其是利用强光的能力强,反映出其在强光条件下生长更快;人工挖坑更新方式的胡杨苗Amax值总体比天然落种更新方式下胡杨苗要高,且胡杨苗Rubisco活性及其CO2同化能力与利用效率、光呼吸速率要高于天然落种更新方式.研究结果表明人工挖坑更新方式下的胡杨苗适宜性更好,在未来有助于塔河中下游胡杨林的更新复壮及植苗技术的示范推广.

To select a suitable regeneration method to rejuvenate the Populus euphratica forest in the lower reaches of the Tarim River, the changes in photosynthesis parameters of Populus euphratica at different seedling ages during the fast-growing period(June-July-August) under artificial digging and natural seeding regeneration methods were analyzed. The photosynthesis-light and CO2 responses of Populus euphratica seedlings at 2 a, 3 a, 5 a and 7 a during the fast-growing period were measured using a US Li-6400 XT photosynthesis instrument. The results show that the photosynthetic potential of Populus euphratica seedlings under artificial pit regeneration is better, especially the ability to use strong light, which reflects faster growth under strong light;The Amax value of Populus euphratica seedlings under artificial pit regeneration is generally higher, and the Rubisco activity, CO2 assimilation capacity, utilization efficiency, and photorespiration rate of Populus euphratica are higher in artificial seed regeneration too. It is concluded that artificial pit regeneration are more suitable, which will help the Populus euphratica forest in the middle and lower reaches of the Tarim River and the demonstration and popularization of planting techniques in future.