| Research Articles |
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| Influences of landform as a confounding variable on SOM-NDVI association in semiarid Ordos Plateau |
| YanYun LUO1, TingXi LIU1, XiXi WANG1,2, LiMin DUAN1 |
1 College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China;
2 Hydraulics/Water Resources Laboratory, Department of Civil and Environmental Engineering, Old Dominion University, Norfolk, VA 23529-0241, USA |
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Abstract Soil organic matter (SOM) plays an important role in maintaining vegetation cover and thus mitigating land erosion of fragile terrestrial ecosystems such as in the Northern Ordos Plateau of China (NOPC). However, little information is available on whether and how SOM varies spatially as an intrinsic characteristic of landform in NOPC. The objective of this study was to examine the spatial associations of SOM with landform and vegetation cover. The study was conducted in a 23,000-km2 area within NOPC because this area has landforms of mobile dunes (MD), flat dunes (FD), grassy sandy land (GSL), flat sandy bedrocks (FSB), and swamps and salt lakes (SW), which are typical landforms in semiarid ecosystems. SOM was determined using a standard laboratory analysis method for 5 cm topsoil samples collected at 72 locations across the study area. In addition, the 250 m Multitem-poral Moderate Resolution Imaging Spectroradiometer (MODIS) imageries taken in the period from August 2006 to August 2010 were used to extract Normalized Difference Vegetation Index (NDVI) which in turn was used as the surrogate of vegetation cover. Classic and geostatistical methods were used to compare SOM concentration across different landforms. The results indicated that an area with a greater value for NDVI (i.e. better vegetation cover) tended to have a higher SOM concentration regardless of the landform types. However, the association between SOM and NDVI varied from one landform to another. The SW and GSL had a highest SOM concentration, while MD had a lowest concentration. For the study area as a whole and the FD, GSL, and MD, SOM was found to be the sole function of NDVI, whereas, for the FSB, SOM was influenced by several intrinsic variables, namely ground surface altitude, slope, and aspect, as well as NDVI. SOM for the SW landform was found to be a function of NDVI. Furthermore, SOM and NDVI exhibited a consistent spatial pattern of increasing from north to south and from west to east. The highest SOM concentration of 3.5% occurred along an east-westward belt, which is adjacent to water pathways, in the mid part of the study area.
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Received: 02 April 2012
Published: 15 December 2012
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| Fund: The National Natural Science Foundation of China (51139002 and 51069005), the Inner Mongolia Agricultural University Innovation Team Building Program (NDTD 2010-6), the Inner Mongolia Scientific and Technology Bureau (20090516), and the Chinese Ministry of Science and Technology (2010DFA71460). |
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| Berhe A A, Harden J W, Torn M S, et al. 2008. Linking soil organic matter dynamics and erosion–induced terrestrial carbon seque¬stration at different landform positions. Journal of Geophysical Research Biogeosciences, 113, G04039, doi:10.1029/2008JG 000751.Dai W H, Huang Y. 2006. Relation of soil organic matter concentration to climate and altitude in zonal soils of China. CATENA, 65(1): 87–94.Dall′O′ M, Kluge W, Bartels F. 2011. FEUWAnet: a multibox water level and lateral exchange model for riperian wetlands. Journal of Hydrology, 250: 40–62.DBWCB (Dalad Banner Water Conservation Bureau). 2007. Intro-duction of ten largest basins [2011-6-2]. http://www.dlt.gov.cn/bmw¬zdh/zfbm/sbj/content/2007–10/17/content_53090.htm.Hou G C, Zhang M S, Liu F, et al. 2008. Groundwater Exploration in the Ordos Basin. Beijing: Geological Publishing House.Jia G M. 2006. The effects of vegetation succession and land Management on soil nutrient, activity and structure of microbial community in the Loess Plateau of Northwest China. Ph.D. Dis-sertation, Lanzhou: Lanzhou University. Jia J. 2000. Rangeland degradation in Ordos Plateau, its nature and assessment. RALA Report, 200: 87–95.Li G Q, Zhang Y R. 2002. Characteristics of regional climate change and pattern analysis on Ordos Plateau. Acta Scientiae Circumstantiae, 14(4): 568–576.Liu L Y, Skidmore E, Hasi E, et al. 2005. Dune sand transport as influenced by wind directions, speed and frequencies in the Ordos Plateau, China. Geomorphology, 67(3–4): 283–297.Luo Y, Liu T, Wang X, et al. 2012. Landform classification using soil data and remote sensing in northern Ordos Plateau of China. Journal of Geographical Sciences. 22(4): 681–698.Lv Y Z, Li B Q, Hu K L, et al. 2002. Spatial variability of soil nutrients with different landforms on Erdos Plateau. Soil and Environmental Sciences, 11(1): 32–37.Martin D, Lal T, Sachdev C B, et al. 2010. Soil organic carbon storage changes with climate change, landform and land use conditions in Garhwal hills of the Indian Himalayan Mountains. Agriculture, Ecosystems & Environment, 138(1–2): 64–73.Neter J, Wasserman W, Kutner M H, et al. 1996. Applied Linear Statistical Models. New York: The McGraw–Hill Companies, Inc.Peng J, Zhang Y Z, Pang X A, et al. 2010. Hyperspectral features of soil organic matter content in South Xinjiang. Arid Land Geography, 55(5): 740–746.Quideau S A, Chadwick O A, Trumbore S E, et al. 2001. Vegetation control on soil organic matter dynamics. Organic Geochemistry, 32: 247–252.Rao W B, Tan H B, Jiang S Y, et al. 2011. Trace element and REE geo¬chemistry of fine- and coarse-grained sands in the Ordos deserts and links with sediments in surrounding areas. Chemie der Erde–Geochemistry, 71(2): 155–170.Six J, Jastrow J D. 2006. Soil organic matter turnover. In: Lal R. Encyclopedia of Soil Science. New York: Marcel Dekker.Sollins P, Homann P, Caldwell B A. 1996. Stabilization and destabilization of soil organic matter: mechanisms and controls. Geoderma, 74: 65–105.SSSSC (State Soil Survey Service of China). 1998. China Soil. Beijing: Chinese Agricultural Press.Stow D, Daeschner S, Hope A, et al. 2003. Variability of the seasonally integrated normalized difference vegetation index across the North Slope of Alaska in the 1990s. International Journal of Remote Sensing, 24(5): 1111–1117.Vähäta A, Søndergaard M, Schlüter L, et al. 1998. Impact of solar radiation on the decomposition of detrital leaves of eelgrass Zostera marina. Marine Ecology Progress Series, 170: 107–117.Wang H, Guo Z H, Xu X H, et al. 2007. Response of vegetation and soils to desertification of alpine meadow in the upper basin of the Yellow River. China. New Zealand Journal of Agricultural Research, 50(4): 491–501.Wang X, Shang S, Yang W, et al. 2010. Simulation of land use–soil interactive effects on water and sediment yields at watershed scale. Ecological Engineering, 36(3): 328–344.Wang Z C, Qian Y B, Zhang H Y, et al. 2011. Spatial distribution of soil physical chemical properties in the region of the northern slopes of Karlike Range in East Tianshan Mountains to Naomaohu Basin. Arid Land Geography, 134(1): 107–114.Xu D Y, Kang X W, Liu Z L, et al. 2009. Assessment of the relative role of climate change and human activities in sandy desertification of Ordos region, China. Science in China: Series D, 39(4): 516– 528.Yang Y C, Hou G C, Zhao Z H, et al. 2008. Formation of mud springs in the Cretaceous Ordos groundwater basin, China and their hydro¬geo¬logical significance. Geological Bulletin of China, 27(8): 1173– 1177.Yoo G, Nissen T M, Wander M M. 2006. Use of physical properties to predict the effects of tillage practices on organic matter dynamics in three Illinois soils. Journal of Environmental Quality, 35: 576–583.Zhang F S, Liu Z X, Geng X Y, et al. 2010. Mapping surface soil organic matter based on multispectral image. 2010 International Conference on Image Analysis and Signal Processing (IASP), April 12–14, 2010, Huaqiao University, Fujian, China.Zhou T, Shi P J, Luo J Y, et al. 2008. Estimation of soil organic carbon based on remote sensing and process model. Journal of Remote Sensing, 11(1): 127–136. |
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