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生态学杂志 ›› 2010, Vol. 29 ›› Issue (06): 1075-1080.

• 研究报告 • 上一篇    下一篇

民勤绿洲-荒漠过渡带植被梯度特征及其土壤水环境

马 瑞1;王继和2**;屈建军1;刘虎俊2;孙 涛2;魏林源2   

  1. 1中国科学院寒区旱区环境与工程研究所沙漠与沙漠化重点实验室,兰州 730000;2甘肃省治沙研究所, 兰州 730000
  • 出版日期:2010-06-10 发布日期:2010-06-10

Vegetation gradient characteristics and soil water environment of oasis-desert transitional zone in Minqin.

MA Rui1;WANG Ji-he2;QU Jian-jun1;LIU Hu-jun2;SUN Tao2;WEI Lin-yuan2   

  1. 1Key Laboratory of Desert and Desertification, Cold and Arid Regions Environment and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;2Gansu Desert Control Research Institute, Lanzhou 730000, China
  • Online:2010-06-10 Published:2010-06-10

摘要: 民勤绿洲-荒漠过渡带的植被和土壤水环境随着与绿洲距离的增加具有明显的空间异质性,在景观分异角度沿绿洲至荒漠方向可划分为4个区段。本文研究了各景观区段上的植被特征以及各区段丘间地及灌丛沙包土壤水分特征。结果表明:过渡带植被总盖度约为36%,灌木盖度为18.7%,草本盖度为18.0%,物种丰富度为19。区段1至区段4,物种组成、植被盖度、优势种、建群种均表现出与各区段立地条件相适应的特征,呈现出大灌木→草本→小灌木→草本的格局,对应的地貌呈现出固定→半流动→半固定→流动的格局。各区段丘间地土壤含水量垂直分布差异较大,5~60 cm为降水主要持水层;因弱透水层的出现,区段1至区段3在60~180 cm含水量出现了第二次波动,水分在弱透水层上的积累为地上植物的生存提供了重要的补给。沙包内土壤含水量从区段1到区段3显著减少。

关键词: 人为侵蚀, 土石场, 空间分布, 景观生态影响度

Abstract: The vegetation and soil water environment in Minqin oasis-desert transitional zone have obvious spatial heterogeneity with the increasing distance from oasis, and can be divided into 4 sections, according to the differentiation of landscapes. This paper studied the vegetation features in each of the sections, and the soil water features in the inter-dunes and shrub islands in the sections. In the transitional zone, the total coverage was about 36%, shrub coverage was 18.7%, and herbal coverage was 18.0%. The species richness was 19. From section 1 to section 4, the species composition, vegetation coverage, dominant species, and constructive species all exhibited the features corresponding to the stand conditions of each section, with a pattern of large shrub→ herb → shrub→ herb. Accordingly, the geomorphology showed the pattern of fixed →semi-shifting → semi-fixed → shifting. There were obvious differences in the vertical distribution of soil water content among the sections, and 5-60 cm soil layer was the main rainwater retention layer. Due to the occurrence of aquiclude, the soil water content appeared a second fluctuation in 60-180 cm soil layer from section 1 to section 3. The water accumulation above the aquiclude was an important supplementary to the aboveground vegetation. The soil water content in the dunes from section 1 to section 3 decreased obviously.

Key words: Artificial erosion, Quarry, Spatial distribution, Landscape ecological impact degree