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| Characteristics of soil seed banks in abandoned croplands at Ansai County on the Hilly-gullied Loess area |
| Bai Wenjuan1,2,Jiao Juying1,3,Zhang Zhenguo1,2 |
| 1.Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,712100,Yangling,Shaanxi;2.Graduate School of the Chinese Academy of Sciences,100039,Beijing;3.Institute of Soil and Water Conservation,Northwest Sci-techonology University of Agriculture and Forestry,712100,Yangling,Shaanxi:China |
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Abstract Field survery and laboratory experiment were conducted to study the characteristics of soil seed bank,such as species composition,density,diversity and similarity in abandoned croplands at Ansai County on the Hilly-gullied Loess area.Results showed that 28 species,which belonged to 11 families and 23 genera,germinated in the 12 plots.Seed density in the 0-5cm layer varied from(900.1±351.3)n·m-2 to(6466.8±1?708.4)n·m-2,as compared with(116.7±61.4) n·m-2 to(2?466.7±914.4)n·m-2 in the 5-10?cm layer.The total seed density of seed bank took a significant decreasing trend as the increasing year since abandoned.Soil seed bank density in sunny slope was 2.2-3.4 times than that in shady slope.The dominant species in sunny slope were Artemisia scoparia and Artemisia hedinii,as compared with Artemisia scoparia in shady slope.As the year since abandoned increased,evenness was significantly related to year since abandoned positively,richness and diversity increased while ecological dominance decreased,which showed that the dominant species is not diversely developed as the year since abandoned increased.The similarity analysis of soil seed bank composition illustrated that the vegetation succession of the abandoned cropland was basicly an enlarging process of spatial heterogeneity.
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Received: 10 November 2006
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