摘要
就鄂尔多斯草地荒漠化过程与植被特征变化的关系进行了研究 .结果表明 :在鄂尔多斯草地荒漠化过程中 ,植物群落退化的趋势为本氏针茅群落→本氏针茅 +油蒿群落→油蒿群落→沙地以及油蒿群落→油蒿 +牛心朴子群落→牛心朴子群落→沙地 .退化阶段植被区系组成的变化表现为物种数和密度先降后升的过程 ,本氏针茅群落→油蒿群落→牛心朴子群落密度的变化幅度为 51.98→ 31.12→ 6 2 .76 (ind .(tus.) /m2 ) ,种数为 15→ 12→ 17种 ;生活型谱变化不明显 ,说明植被的退化主要是群落中优势种的衰退造成的 ;生物量的变化幅度较大 ,为 2 18.1→74 8.72→ 155.6 (g/m2 ) ;植物水分生态类型表现为中旱生植物逐渐减少 。
The correlation between the desertification of the grassland and the changes of vegetation characteristics in Erduosi is reported in this paper. The results show that: in the desertification course of the grassland, the degradation pathway of the community is both from Stipa bungeana community → S. bungeana + died Artemisia ordosia community → S. bungeana + A. ordosica community → A. ordosica community → sandland and from A. ordosica community → A. ordosica + Cynanchum komarovii community → C. komarovii community → sandland. The Stipa bungeana community is the desert steppe community, the Artemisia ordosia community is the dominating community in the Erduosi sandland, and the Cynanchum komarovii community is the indicator community at the last stage in the desertification. As the Artemisia ordosia community degenerates, it will be replaced by either Stipa bungeana community or the Cynanchum komarovii community, and their habitats become from flowing sand dune to fixed sand dune to fixed sand dune with hard crust. The studies , of the flora , density and biomass of community, show that: the changes of the flora and density are characterized by the trends of their increasing firstly and declining afterwards, and the species number changes from 15 to 12 and to 17 species, and the density from 51.98 →31.12 → 62.76? ind.(tus.)/m 2 during the desertification from Stipa bungeana community to Artemisia ordosica community and to Cynanchum komarovii community. Because of the occasional species happening in considerable proportion, the flora and density of the communities have obviously seasonal changes, which shows that the flora and density are closely correlated with the simultaneous rainfall. The life form spectrum changes little: semi shrub occupies 13.3%, perennials 69.1% in Stipa bungeana community; semi shrub 8.3%, perennials 64.9% in the Artemisia ordosica community; and semi shrub 5.9%, perennials 64.8% in the Cyn
出处
《南京大学学报（自然科学版）》
CAS
CSCD
北大核心
2001年第2期232-239,共8页
Journal of Nanjing University（Natural Science）
基金
国家自然科学基金!重大项目 ( 3 9990 4 90 )
