Regenerative Role of Soil Seed Banks of Different Successional Stages in A Saline-alkaline Grassland in Northeast China  

作　　者：MA Hongyuan LI Jingpeng YANG Fan Lü Xiaotao PAN Yuepeng LIANG Zhengwei 

机构地区：[1]Da'an Sodic Land Experiment Station,Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun 130102,China [2]Erguna Forest-Steppe Ecotone Research Station,Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China [3]State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospherie Chemistry,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China

出　　处：《Chinese Geographical Science》2018年第4期694-706,共13页中国地理科学（英文版）

基　　金：Under the auspices of National Basic Research Program of China(No.2015CB150802);National Natural Science Foundation of China(No.41371260,41771058);National Key Research&Development Program of China(No.2016YFC0501200);National Key Basic Survey of Resources(No.2015FY110500)

摘　　要：Soil seed banks can act as a potential seed source for natural revegetation and restoration. However, in a saline-alkaline grassland, it remains unclear how the stages of vegetation succession affect the characteristics of soil seed banks and the potential of soil seed banks of different successional stages for vegetation restoration. In this study, seasonal changes of the soil seed bank, and seed production and dispersal dynamics along degradation successional gradients were investigated in a saline-alkaline grassland in Northeast China, where the dominant grass during the 1960 s, Leymus chinensis was replaced with the secondary successional order of Puccinellia chinampoensis, Chloris virgata, and Suaeda salsa, together with bare patches. It was found that the soil seed bank composition varied according to the changing vegetation and had the highest species richness(7–16) in the climax successional stage, but had a low S?rensen similarity(0.22–0.37) with the aboveground vegetation. There was a high seed density of the soil seed bank(21 062–62 166/m2 in August and December) and also high S?rensen similarity index values(0.47–0.60) in the secondary successional stages of P. chinampoensis, C. virgata, and S. salsa. In bare patches, there were many seeds in the soil seed bank and some seedlings also appeared in the aboveground vegetation, indicating the existence of a persistent soil seed bank. Seed density and species richness differed substantially among the different successional stages, which was related to the reproductive characteristics of the standing plants in vegetation communities. Due to the lack of propagules of perennial species, especially the climax species of L. chinensis, in the soil, the successful restoration of the degraded saline-alkaline grassland was not possible. The study proved that in a degraded saline-alkaline grassland dominated by biennial or annual species, the soil seed bank was important for the revegetation of the current dominant plants, but not for the restoration of the Soil seed banks can act as a potential seed source for natural revegetation and restoration. However, in a saline-alkaline grassland, it remains unclear how the stages of vegetation succession affect the characteristics of soil seed banks and the potential of soil seed banks of different successional stages for vegetation restoration. In this study, seasonal changes of the soil seed bank, and seed production and dispersal dynamics along degradation successional gradients were investigated in a saline-alkaline grassland in Northeast China, where the dominant grass during the 1960 s, Leymus chinensis was replaced with the secondary successional order of Puccinellia chinampoensis, Chloris virgata, and Suaeda salsa, together with bare patches. It was found that the soil seed bank composition varied according to the changing vegetation and had the highest species richness（7–16） in the climax successional stage, but had a low S？rensen similarity（0.22–0.37） with the aboveground vegetation. There was a high seed density of the soil seed bank（21 062–62 166/m2 in August and December） and also high S？rensen similarity index values（0.47–0.60） in the secondary successional stages of P. chinampoensis, C. virgata, and S. salsa. In bare patches, there were many seeds in the soil seed bank and some seedlings also appeared in the aboveground vegetation, indicating the existence of a persistent soil seed bank. Seed density and species richness differed substantially among the different successional stages, which was related to the reproductive characteristics of the standing plants in vegetation communities. Due to the lack of propagules of perennial species, especially the climax species of L. chinensis, in the soil, the successful restoration of the degraded saline-alkaline grassland was not possible. The study proved that in a degraded saline-alkaline grassland dominated by biennial or annual species, the soil seed bank was important for the revegetation of the current dominant plants, but not for the

关 键 词：soil seed bank seed dispersal ecological restoration PHENOLOGY SUCCESSION seed rain 

分 类 号：S812[农业科学—草业科学]