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中国沙漠 ›› 2009, Vol. 29 ›› Issue (5): 885-890.

• 生物土壤与生态 • 上一篇    下一篇

塔里木河下游荒漠化过程土壤种子库特征

王增如1,2, 徐海量1, 尹林克1, 李吉玫1, 张占江3, 李 媛1   

  1. 1.中国科学院 新疆生态与地理研究所 绿洲生态与荒漠环境重点实验室, 新疆 乌鲁木齐 830011; 2.中国科学院 寒区旱区环境与工程研究所, 甘肃 兰州 730000; 3.新疆农业大学 农学院, 新疆 乌鲁木齐 830052
  • 收稿日期:2008-04-22 修回日期:2008-07-13 出版日期:2009-09-07 发布日期:2009-09-07

Characteristics of Soil Seed Bank along Desertification Gradient in Lower Reaches of Tarim River

WANG Zeng-ru1,2, XU Hai-liang1, YIN Lin-ke1, LI Ji-mei1, ZHANG Zhan-jiang3, LI Yuan1   

  1. 1.Key Laboratory of Oasis Ecology and Desert Environment, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; 2.Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 3.Agronomy College of Xinjiang Agriculture University, Urumqi 830052, China
  • Received:2008-04-22 Revised:2008-07-13 Online:2009-09-07 Published:2009-09-07

摘要: 沿塔里木河下游荒漠河岸林,选择了荒漠化程度依次加重的5个断面,进行了土壤种子库野外萌发试验。结果表明:①在中度荒漠化区土壤种子库的物种相对丰富(11种),密度较高(892.6粒\5m-2);随着荒漠化程度的加剧,土壤种子库物种丰富度、总密度以及多样性指数呈现出明显下降的趋势;②与重度荒漠化区和中度荒漠化区相比,极度荒漠化区土壤种子库中的多年生草本和灌木密度占总密度的百分比有所增加,一年生草本百分比明显降低;③不同荒漠化程度对种子库密度的垂直分布影响不大,70%以上的种子集中在土壤表层0~2 cm深度。综合来看,随着荒漠化程度的加剧,土壤种子库的恢复潜力有所下降。

关键词: 土壤种子库, 塔里木河下游, 荒漠化程度, 恢复潜力

Abstract: Over the past 50 years the desert riparian vegetation in the lower reaches of the Tarim River in western China degraded due to irrational management regimes. Little is known about the effect of vegetation degradation level on the structure and performance of soil seed bank in desert riparian vegetation. A field experiment was established to test this effect. The results showed that the density (892.6 seeds\5m-2) and species number(11 species) of soil seed banks in the moderate-desertification transects are relatively high. With the increase of desertification level the species abundance, density and biodiversity index of soil seed bank decrease. There is no significant effect of desertification intensity on the vertical density distribution of soil seed bank. However, over 70% of seeds were concentrated in the upper oil layer (0~2 cm). Plots at extreme desertification level showed a greater proportion of annual herbs compared to plots at heavy or moderate desertification levels, whereas perennial herbs and shrubs followed the inverse trend. These results indicate that the potential of the natural vegetation to restore naturally decreases with the increase of desertification level.

Key words: soil seed bank, lower reaches of Tarim River, desertification level, potential for restoration

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