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中国沙漠 ›› 2008, Vol. 28 ›› Issue (4): 657-664.

• 生物土壤与生态 • 上一篇    下一篇

塔里木河下游退化荒漠河岸林地上植被与土壤种子库关系初探

徐海量1, 李吉玫1, 张占江1, 叶 茂2, 王增如1   

  1. 1.中国科学院新疆生态与地理研究所, 新疆 乌鲁木齐 830011; 2.新疆师范大学地球科学与旅游学院, 新疆 乌鲁木齐 830054
  • 收稿日期:2007-06-18 修回日期:2007-09-10 出版日期:2008-07-20 发布日期:2008-07-20

Study on Relation Between Soil Seed Bank and Standing Vegetation along Different Degradation Levels of Desert Riverside Forest in Lower Reaches of Tarim River

XU Hai-liang1, LI Ji-Mei1, Zhang Zhan-Jiang1, YE Mao2, WANG Zeng-ru1   

  1. 1.Xinjiang Institute of Ecology and Geography Research, Chinese Academy of Sciences, Urumqi 830011, China; 2.College of Earth Science and Tourism, Xinjiang Normal University, Urumqi 830011, China
  • Received:2007-06-18 Revised:2007-09-10 Online:2008-07-20 Published:2008-07-20

摘要: 以塔里木河下游为研究区,选择退化程度不同的4个典型断面19个样地,利用种子萌发法进行了两年的种子库土壤萌发实验,试图就生态严重退化区的土壤种子库与地上植被的关系以及退化程度的差异对种子库特征的影响开展针对性的研究。结果显示: ①塔里木河下游土壤种子库的基本特征是:种子库密度小、物种种类组成较单一、物种的多样性低和地上植被与种子库的相似性较低;②随退化程度的加剧,土壤种子库密度明显下降、表层种子库比例升高、一年生草本占优势逐渐向多年生草本和灌木转变、地上植被与土壤种子库物种组成上差异显著;③退化过程中种子库多样性的变化比地上植被变化要迟缓,但是在植被退化演替的末期,土壤种子库的物种多样性指数衰减的幅度又明显快于地上植被的衰减幅度;④受干旱环境和严重退化的双重影响塔里木河下游土壤种子库与地上植被的关系表现出退化演替末期共有物种数的减少和相似性明显递减的特点。

关键词: 塔里木河下游, 土壤种子库, 地上植被, 关系

Abstract:

Experiments for two years on seed bank germination were conducted in nineteen plots at four typical transects under different vegetation degradation levels along the lower reaches of Tarim River in Xinjiang, aiming to study the relation between standing vegetation and soil seed bank in severely ecological degradation area. Results show that: ①from lightly degraded region to extremely degradation region, the relative density, relative cover and relative frequency of the annual and perennial species gradually decrease, but the relative density, relative cover and relative frequency of the shrub and arbor gradually increase; the cover of dominant species also declines, and the cover and the diversity of the vegetation community obviously decline. ②The seed bank density in the lower reaches of Tarim River ranges from 166 to 2 012 seed·m-2. The AVON results show that there are remarkable differences in soil seed bank density along different vegetation degradation levels (F=7.922, P<0.05). The vertical distribution of seed bank is that the seed bank density reduces with the increase of the depth, 0—5 cm occupying 71%, 6—10 cm 19%,11—30 cm occupying 10%. In the lightly degraded region, the life form of seed bank is predominated by the annual, but with the degradation level increasing, the life form shifts from annual to shrub and arbor, and the diversity of soil seed bank gradually declines. ③The Sorensen’s similarity coefficient between seed bank and the standing vegetation is low, averagely 0.219. The number of co-occurring species both in the seed bank and the standing vegetation decrease with the degradation level increasing.

Key words: lower reaches of Tarim River, soil seed bank, standing vegetation, relation

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