景电引黄灌区植被变化过程与恢复模式研究

摘要

In this study,we focused on the natural and artificial vegetations in Yellow River irrigated area of Jingtai.Issues related to vegetation restoration in the irrigated area were examined,such as the plant growth situations,restoration and enclosure protection,shrub stumping for renewing,and the models of optimal modification for farmland shelterbelt.The change process and restoration technology were analyzed since 1970s.The results showed:1) the vegetation coverage gradually increased and the dune gradually fixed with large range planting artificial vegetation around oasis,the natural species type changed from Nitraria tangutorum to Artemisia ordosica,A.ordosica had strongly adaptability in this area.2) Within inner oasis,in lowland where salty water pooled,N.tangutorum degenerated in large area,Reaumuria songarica and Tamarix ramosissima almost disappeared,but Phragmites communis increased greatly,the main vegetations currently occurred were P.communis and Kalidium foliatum;in highland,there was little change,the dominant species were K.foliatum and Salsola passerine.R.songarica and Phragmites australis were dominant species in the unsuitable for farming area.3) The artificial measures could enhance the restoration process of degenerated desert shrubs,such as enclosure and stumping shrubs could improve the ability of natural regeneration and branching,increase plant growth,enrich plant species,and increase plant density.4) Optimal modification farmland shelterbelt were necessary to construct steady and sustainable eco-economic type of shelter systems with Populous tomentosa,Elaeagnus angustifolia,Robinia pseucdoacacia and Pinus sylvestris,etc.,also with reasonable model.%以景电引黄灌区天然植被和人工植被为研究对象,通过植被生长现状调查,退化沙生灌木封育保护和平茬人工干预恢复试验,衰败农田防护林优化改造模式研究,开展20世纪70年代末至今景电引黄灌区植被变化过程与恢复技术研究.结果表明:1)绿洲外围大面积建设人工固沙灌木林,植被覆盖度增加,沙丘慢慢固定,天然植被的类型由白刺为主的群从逐渐转变为以油蒿为主的群从,油蒿在当地具有极强的适应性.2)绿洲内部,地势较低的集水积盐区,白刺大面积退化,红砂、红柳已基本消失,芦苇大量增加,目前植被以芦苇和盐爪爪为主.地势较高的沙砾质草地,植被基本没有变化,以盐爪爪和珍珠猪毛菜为主;石质山坡等不适宜耕作的荒滩,红砂、沙生针茅等物种逐渐成为优势种.3)封育保护和平茬人工干预措施,可以提高植物自然更新能力、分枝能力,增加植物生长量、物种丰富度和植株密度,对退化固沙灌木林的恢复具有良好的促进作用.4)选择三倍体毛白杨、沙枣、刺槐、樟子松、枣树等树种,配置合理模式改造农田防护林,建成稳定可持续的生态经济型防护林网.