| Research Articles |
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| Effect of spatial scale and topography on spatial heterogeneity of soil seed banks under grazing disturbance in a sandy grassland of Horqin Sand Land, Northern China |
| XiaoAn ZUO 1,2, ShaoKun WANG 1,2, XueYong ZHAO 1,2, WenJin LI3, Johannes KNOPS4, Amy KOCHSIEK4 |
1 Naiman Desertification Research Station, Cold and Arid Regions of Environmental and Engineering Research Institute, Chi-nese Academy of Sciences, Lanzhou 730000, China;
2 Laboratory of Plant Stress Ecophysiology and Biotechnology, CAREERI, Chinese Academy of Sciences, Lanzhou 730000, China;
3 Key Laboratory of Arid and Grassland Ecology of Ministry of Education, Lanzhou University, Lanzhou 730000, China;
4 School of Biological Sciences, University of Nebraska-Lincoln, Lincoln 62588, USA |
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Abstract Soil seed banks play an important role in the distribution and composition of plant communities in semiarid grassland ecosystems. However, information on how spatial scale influences the spatial heterogeneity of soil seed banks in a grassland under grazing disturbance is still lacking. Based on field sampling and greenhouse germination, we measured the species composition and seed density of soil seed banks at different spatial scales (30 m×30 m, 30 m×60 m and 30 m×90 m) along a topographical gradient in a sandy grassland in Horqin Sand Land, Northern China. By applying geostatistical methods, we examined how spatial scale and topography affected the spatial distribution of soil seed banks in the study area. Our results showed that the total number of species in soil seed banks, as well as the number of dominant annuals, increased with the increase of spatial scales. Seed density in soil seed banks decreased with the increase of spatial scales due to an increase in the slopes and relative heights of the sampling points. Geostatistical analysis showed that the relative structural variance (C/(C0+C)) of seed density and species richness were over 65% for all spatial scales, indicating that these variables had an obvious spatial autocorrelation and the spatial structured variance accounted for the largest proportion of the total sample variance. Spatial autocorrelation of seed density in soil seed banks increased with the increase of measured scales, while that of species richness showed a reverse trend. These results suggest that the total number of species in soil seed banks is spatial scale dependent and lower topography may accommodate more seeds. Spatial distribution of seed density in soil seed banks is also scale dependent due to topographic variation. Grassland management, therefore, needs to consider local grazing disturbance regime, spatial scale and topography.
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Received: 02 November 2011
Published: 06 June 2012
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| Fund: The National Natural Science Foun-dation of China (41171414), the Knowledge Innovation Pro-gram of Chinese Academy of Sciences (KZCX2-EW-QN313), the National Science and Technology Support Program (2011BAC07B02), the National Basic Research Program of China (2009CB421303) and the West Light Foundation of the Chinese Academy of Sciences (0928711001). |
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| Adler P B, Raff D A, Lauenroth W K. 2000. The effect of grazing on the spatial heterogeneity of vegetation. Oecologia, 128(4): 465–479.Aguiar M R, Sala O E. 1997. Seed distribution constrains the dynamics of the Patagonian steppe. Ecology, 78(1): 93–100.Auestad I, Rydgren K, Økland R H. 2008. Scale-dependence of vegeta-tion-environment relationships in semi-natural grasslands. Journal of Vegetation Science, 19(1): 139–148.Augustine D J. 2003. Spatial heterogeneity in the herbaceous layer of a semi-arid savanna ecosystem. Plant Ecology, 167(2): 319–332.Bengtson P, Falkengren-Grerup U, Bengtsson G. 2006. Spatial distri-butions of plants and gross N transformation rates in a forest soil. Journal of Ecology, 94(4): 754–764.Ben-Natan G, Abramsky Z, Kotler B P, et al. 2004. Seed redistribution in sand dunes: a basis for coexistence of two rodent species. Oikos, 105(2): 325–335.Caballero I, Olano J M, Loidi J, et al. 2003. Seed bank structure along a semi-arid gypsum gradient in Central Spain. Journal of Arid Envi-ronments, 55(2): 287–299.Cannavacciuolo M, Bellido A, Cluzeau D, et al. 1998. A geostatistical approach to the study of earthworm distribution in grassland. Ap-plied Soil Ecology, 9(1–3): 345–349.Crawley M J, Harral J E. 2001. Scale dependence in plant biodiversity. Science, 291(5505): 864–867.Dölle M, Schmidt W. 2009. The relationship between soil seed bank, above-ground vegetation and disturbance intensity on old-field suc-cessional permanent plots. Applied Vegetation Science, 12(4): 415–428.Frank D A, Inouye R, Huntly N, et al. 1994. The biogeochemistry of a north-temperate grassland with native ungulates: nitrogen dynamics in Yellowstone National Park. Biogeochemistry, 26(3): 163–188.Gamma Design Software GS+5.3. 2002. Geostatistics for the Environ-mental Sciences. Plainwell, Michigan, USA. [2011-10-23]. http://www.gammadesign.com.Harrison S, Davies K F, Safford H D, et al. 2006. Beta diversity and the scale-dependence of the productivity-diversity relationship: a test in the Californian serpentine flora. Journal of Ecology, 94(1): 110–117. He Z B, Zhao W Z. 2006. Characterizing the spatial structures of ripar-ian plant communities in the lower reaches of the Heihe River in China using geostatistical Techniques. Ecological Research, 21(4): 551–559.Isaaks E, Srivastava R. 1989. Applied Geostatistics. New York: Oxford University Press.Kahmen A, Perner J, Audorff V, et al. 2005. Effects of plant diversity, community composition and environmental parameters on produc-tivity in montane European grasslands. Oecologia, 142(4): 606–615.Landsberg J, James C D, Maconochie J, et al. 2002. Scale-related ef-fects of grazing on native plant communities in an arid rangeland re-gion of South Australia. Journal of Applied Ecology, 39(3): 427–444.Li F R. 2008. Presence of shrubs influences the spatial pattern of soil seed banks in desert herbaceous vegetation. Journal of Vegetation Science, 19(4): 537–548.Li F R, Zhao L Y, Zhang H, Li J L, et al. 2009. Habitat degradation, topography and rainfall variability interact to determine seed distri-bution and recruitment in a sand dune grassland. Journal of Vegeta-tion Science, 20(5): 847–859.Liu Z, Yan Q, Li X, et al. 2007. Seed mass and shape, germination and plant abundance in a desertified grassland in northeastern Inner Mongolia, China. Journal of Arid Environments, 69(2): 198–211.Ma J L, Liu Z M. 2008. Spatiotemporal pattern of seed bank in the annual psammophyte Agriophyllum squarrosum Moq. (Chenopodi-aceae) on the active sand dunes of northeastern Inner Mongolia, China. Plant and Soil, 311(1–2): 97–107.Ma M J, Zhou X H, Du G Z. 2010. Role of soil seed bank along a dis-turbance gradient in an alpine meadow on the Tibet plateau. Flora, 205(2): 128–134.Milchunas D G, Sala O E, Lauenroth W K. 1988. A generalized model of the effects of grazing by large herbivores on grassland community structure. American Naturalist, 132(1): 87–106.Nathan R, Muller-Landau H C. 2000. Spatial patterns of seed dispersal, their determinants and consequences for recruitment. Trends in Ecology and Evolution, 15(7): 278–285.Noy-Meir I, Gutman M, Kaplan Y. 1989. Responses of Mediterranean grassland plants to grazing and protection. Journal of Ecology, 77(1): 290–310.Oba G, Weladji R B, Lusigi W J, et al. 2003. Scale-dependent effects of grazing on rangeland degradation in northern Kenya a test of equilibrium and non-equilibrium hypotheses. Land Degradation and Development, 14(1): 83–94.Oline D K, Grant M C. 2001. Scaling patterns of biomass and soil properties: an empirical analysis. Landscape Ecology, 17(1): 13–26.Olofsson J, de Mazancourt C, Crawley M J. 2008. Spatial heterogeneity and plant species richness at different spatial scales under rabbit grazing. Oecologia, 156(4): 825–834.Palmer T M. 2003. Spatial habitat heterogeneity influences competition and coexistence in an African acacia ant guild. Ecology, 84(11): 2843–2855.Russell S K, Schupp E W. 1998. Effects of microhabitat patchiness on patterns of seed dispersal and seed predation of Cercocarpus ledi-folius (Rosaceae). Oikos, 81(3): 434–443.Ryberg W A, Chase J M. 2004. Connectivity, scale-dependence, and the productivity-diversity relationship. Ecology Letters, 7(8): 676–683. Wang S K, Zhao X Y, Qu H, et al. 2010. Variation in soil water content to rainfall under Caragana microphylla shrub in Horqin Sandy Land. Journal of Arid Land, 2(3): 174−179.Spiegelberger T, Matthies D, Müller-Schärer H, et al. 2006. Scale-dependent effects of land use on plant species richness of mountain grassland in the European Alps. Ecography, 29(4): 541–548.Sternberg M, Gutman M, Perevolotsky A, et al. 2000. Vegetation re-sponse to grazing management in a Mediterranean herbaceous com-munity: a functional group approach. Journal of Applied Ecology, 37(2): 224–237.Turner W R, Tjorve E. 2005. Scale-dependence in species-area rela-tionships. Ecography, 28(6): 721–730.Wallis De Vries M F, Bakker J P, van Wieren S F. 1998. Grazing and Conservation Management. Dordrecht: Kluwer Academic Publishers.Wang S M, Zhang Y, Li L, et al. 2005. Spatial distribution patterns of the soil seed bank of Stipagrostis pennata (Trin.) de Winter in the Gurbantonggut Desert of north-west China. Journal of Arid Envi-ronments, 63(1): 203–222.Wang Y S, Shiyomi M, Tsuiki M, et al. 2002. Spatial heterogeneity of vegetation under different grazing intensities in the Northwest Heilongjiang Steppe of China. Agriculture Ecosystem and Environ-ment, 90(3): 217–229.Wellstein C, Otte A, Waldhardt R. 2007. Seed bank diversity in mesic grasslands in relation to vegetation type, management and site condi-tions. Journal of Vegetation Science, 18(2): 153–162.Witkowski E T F, Garner R D. 2000. Spatial distribution of soil seed banks of three African savana woody species at two contrasting sites. Plant Ecology, 149(1): 91–106.Woldu Z, Mohammed Saleem M A. 2000. Grazing induced biodiver-sity in the highland ecozone of East Africa. Agriculture Ecosystem and Environment, 79(1): 43–52.Xu M, Qi Y, Chen J Q, et al. 2004. Scale-dependent relationships between landscape structure and microclimate. Plant Ecology, 173(1): 39–57.Yan Q, Liu Z, Zhu J, et al. 2005. Structure, pattern and mechanisms of formation of seed banks in sand dune systems in northeastern Inner Mongolia, China. Plant and Soil, 277(1–2): 175–184.Zhao H L, Zhao X Y, Zhang T H, et al. 2005. Desertification processes of sandy rangeland due to over-grazing in semi-arid area, Inner Mongolia, China. Journal of Arid Environments, 62(2): 309–319.Zuo X A, Zhao H L, Zhao X Y, et al. 2008. Spatial pattern and hetero-geneity of soil properties in sand dunes under grazing and restoration in Horqin Sandy Land, Northern China. Soil and Tillage Research, 99(2): 202–212.Zuo X A, Zhao X Y, Zhao H L, et al. 2009. Spatial heterogeneity of soil properties and vegetation-soil relationships following vegetation restoration of mobile dunes in Horqin Sandy Land, Northern China. Plant and Soil, 318(1–2): 153–167. |
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