油蒿在沙坡头地区沙地植被演替中的地位

本文通过对沙坡头地区铁路两侧人工植被和天然植被演替过程的调查研究,应用定性和定量分析方法,论述了油蒿在沙坡头地区沙地植被演替中的地位及稳定性。油蒿是沙生演替系列中的前期植物种之-,随着沙面表土层的增厚及生境的旱化,如果不受人为干扰,最终将被其它植物群落所代替。然而,只要地表保持沙质疏松,油蒿就能很顺利地天然更新,并以其发达的浅层根系对水分的竞争能力,使其在群落中占据着优势地位。因此,在人畜对地表的长期扰动下,油蒿在本地区可以形成-种相对稳定的群落或偏途演替顶极。

The Status of Artemisia ordosica in Vegetation Succession at Shapotou Area

By the observation on the successions of both artificial sand-holding vegetation and natural vegetation along the railway at Shapotou Area and the quanlitative and quantitative analyses, the status of A rtemisia ordosica and its stability in this area vegetation successions are presened and discussed. Artemisia ordosica is one of the earlier stage species in psammosere. With the thickening of topsoil and the gradual aridization of site, the community of Artemisia ordosica will be terminally replaced by other plant communities if human interventions were stopped. Conversely, in the case of keeping loose surface texture the species will regenerate naturally and occupy dominant position in the community by the high water competition capability relying on well-developed root system in the topsoil. It is concluded that this species can be developed in to a relative stable community or disclimax at Shapotou area when human or animals' interventions were exerted on the ground.