甘肃胡杨恢复发展的限制因子及对策

THE RESTRICTIVE FACTORS AND THE DEVELOPMENT STRATEGIES OF FOREST RESTORATION OF POPULUS EUPHRATICA OLIV. IN GANSU

甘肃胡杨正处于负向演替的衰退状态，在现存的１４５９０ｈｍ２胡杨林中，衰退林和成熟林就占了７３．０％，且大多为胡杨疏林；而树龄小于１５年的幼龄林仅占了５．０％，１～５年生天然更新苗十分罕见。影响、限制甘肃胡杨天然林恢复发展的主要因子是林地水土环境的恶化；而胡杨无性繁殖困难、实生苗在生长形态方面表现参差不齐等因素，又限制了胡杨的人工发展。只有在突破胡杨无性繁殖难关的基础上，通过良种繁育调动群众营建人工胡杨林的积极性。

Populus euphratica Oliv. is in its declining stage of negative succession in Gansu Province. There are 73 0% declining and mature forest which grow sparsely, 5% young forest less than 15 years and rare seedings between 1 and 5 years in the 14 590 hm 2 populus forest. The main restrictive factors of development lie in both the deterioration of water soil environment and the disadvantages in artificial forest resulted from the difficult propagation and not uniform seedlings of Populus euphratica Oliv. The development strategies of P.euphratica . had been suggested that only with the combination of successive vegetative propagation and breeding desirable varieties, afforestation with improved varieties in a large scale could be practical.