摘要
研究了北京沿河沙地I 2 1 4杨树人工林地下滴灌和常规灌溉林地树木生长与光合特性 ,结果表明 :与常规灌溉相比 ,地下滴灌能大大增加树木的生长量 ,提高林地生产力。 2 0 0 0年 (栽植第 4年 ) ,地下滴灌区树木平均胸径、树高和单株材积分别达到 2 1 1 8cm、1 4 2 3m和 0 1 81 5m3,比常规灌溉增加了 5 4 5 %、36 9%和 2 4 7 6 % ;林地生产力达到 2 2 78～ 2 5 81m3·hm- 2 a- 1 ,比常规灌溉增加了 3 9～ 4 6倍。树木生长改善和林地生产力提高的生理机制是地下滴灌可促进树木光合作用和水分利用效率。地下滴灌区树木叶净光合速率在一天中几乎一直显著高于对照 ,幅度达 1 0 0 %～ 2 1 4 % ;从一个滴灌周期来看 ,滴灌区树木叶净光合速率显著高于对照 9 0 %～ 9 9% ;滴灌区树木水分利用效率也较对照区显著提高。通过相关分析表明 ,表层土壤 (1 5～ 2 5cm)水分含量在 5 %～ 8%时树木叶净光合速率能在长时间维持较高水平 ,而水分含量低于 4 % ,树木叶净光合速率将降低。建议在干旱半干旱和季节性干旱地区营造速生丰产用材林时应结合当地经济条件推广地下滴灌技术 ,这不仅有利于水资源的可持续利用 ,而且将大幅度提高林地生产力 ,使我国人工林生产力赶超世界先进水平。
The growth and photosynthesis of I\|214 poplar trees ( Populus×euramericana cv. 'I\|214 ') in the plantations with subterranean drip irrigation(SDI) and normal irrigation(NI) on sandy soil in Beijing were studied in this paper. The results showed that: the growth and yields of the plantations were more increased on SDI than on NI. In 2000 (4 years after planting), the average D 1 3 , H and volume per tree were 21 18?cm, 14 23?m and 0 181 5?m 3 on SDI,54 5%、36 9% and 247 6% more than on NI; The yields of the plantations with SDI reached 22 78～25 81?m 3·hm -2 a -1 which were 3 9～4 6 times as much as that with NI. The physiological mechanism of improving the growth of trees and increasing the productivity of forest land was the subterranean drip irrigation,by which the photosynthesis and water use efficiency of trees grown in the plantation would be promoted. The net photosynthetic rate of leaves for poplar trees irrigated with SDI was still significant higher than that with NI in the different time of a day, ranged from 10 0%～21 4%. During an irrigation cycle, the net photosynthetic rate of leaves with SDI was also significant higher than that with NI, ranged from 9 0%～9 9%. Water use efficiency of trees with SDI was also higher than that with NI. The correlativity study showed that the net photosynthetic rate of poplar trees leaves could contain a high level for a long time when the water content of subsurface soil (15～25?cm) was 5%～8%; but it would be decreased when the water content was lower than 4%. At last, extending the subterranean drip irrigation in developing the fast growing and high yield plantations in arid, semi arid area, and season arid area was suggested according to the local economic condition. It could not only accelerate the sustainable usage of water resources, but also could increase the plantation productivity and make it reach the high level of the world.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2004年第2期61-67,共7页
Scientia Silvae Sinicae
基金
国家教育部博士点基金资助项目
北京市林业局重点项目
关键词
地下滴灌
杨树
速生丰产林
生长特性
光合特性
林地生产力
Poplar, Fast growing and high yield plantation, Subsurface drip irrigation, Plantation yield, Photosynthesis
