Comparing soil carbon estimates in glaciated soils at a farm scale using geospatial analysis of field and SSURGO data
Comparing soil carbon estimates in glaciated soils at a farm scale using geospatial analysis of field and SSURGO data
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使用现场地理空间分析和 SSURGO 数据比较农场规模的冰川土壤中的土壤碳估算
DOI：
10.1016/j.geoderma.2016.06.029
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发表时间：
2016
期刊：
影响因子：
6.1
通讯作者：
M. Schlautman
中科院分区：
文献类型：
--
作者：
E. Mikhailova;Abduljaleel Altememe;A. A. Bawazir;R. D. Chandler;M. Cope;C. Post;Roxanne Stiglitz;H. Zurqani;M. Schlautman
土壤碳是与生态系统服务相关的关键土壤属性，常用于不同尺度的土壤碳含量估算。土壤碳估计的不确定性往往源于田间、实验室和/或农场规模的地理空间数据的变异性。这项研究的目的是量化和比较纽约州北部147公顷的田间土壤有机碳(SOC)、土壤无机碳(SIC)和土壤总碳(TC)的水平，基于三种不同的分析方法：a)使用土壤调查地理(SSURGO)空间数据库报告的田间站点存在的每个土壤地图单元(SMU)的碳浓度，并将该值应用于每个SMU；b)平均在特定SMU边界内收集的土芯的碳含量，并在每个SMU上应用平均值；以及c)基于单个土芯对整个田间站点的碳含量进行内插。基于内插岩心样本的SOC、SIC和TC含量图不同于通过在SMU上应用平均岩心结果或SSURGO值而创建的图。碳的大小和空间分布的差异可以归因于几个因素。例如，SSURGO土壤碳值通常是从“类型位置”而不是从实际研究位置测量选定的个体(S)的。这些“类型地点”可能远离研究地点，甚至可能位于不同的州。此外，与系统的野外测量相比，SSURGO土壤碳值可能高估了实际含量，因为较低深度的SSURGO值通常是从上层土壤层位推断出来的。这种外推对无机碳的影响比对有机碳的影响要大得多，因此，在目前的研究中，SSURGO数据库的SOC估计值与实地测量结果之间的一致性更好。由于现场测量和实验室测量的高成本，区域和/或全球碳估计很少使用详细的现场数据，因此需要额外的现场采样来限制和改进这些估计，并评估存在的潜在变异性。
Soil carbon is a key soil property related to ecosystem services and it is often used in soil carbon content estimates at various scales. Uncertainties in soil carbon estimates often arise from variability in field, laboratory, and/or geospatial data at a farm scale. The objectives of this study were to quantify and compare levels of soil organic carbon (SOC), soil inorganic carbon (SIC), and total soil carbon (TC) for a 147-hectare field site in upstate New York based on three alternative analysis procedures: a) using carbon concentrations reported by the Soil Survey Geographic (SSURGO) spatial databases for each soil map unit (SMU) present at the field site and applying that value across each SMU; b) averaging the carbon contents of soil cores collected within a specific SMU boundary and applying the averaged value across each SMU; and c) interpolating carbon contents across the field site based on the individual soil cores. Maps of SOC, SIC, and TC contents based on the interpolated core samples were different from maps created by applying averaged core results or SSURGO values across the SMUs. Differences in the magnitudes and spatial distributions of carbon can be attributed to several factors. For example, SSURGO soil carbon values are frequently measured for a selected pedon(s) from a “type location” and not from the actual study location. These “type locations” can be located far from study sites and even in different states. Also, SSURGO soil carbon values may overestimate the actual contents when compared to systematic field measurements because the SSURGO values at lower depths are often extrapolated from upper soil horizons. Such extrapolations affect inorganic carbon to a much greater extent than organic carbon, therefore better agreement is observed in the present study between SOC estimates from the SSURGO database and field measurements. Because regional and/or global carbon estimates are rarely made with detailed field data due to the high costs of field and laboratory measurements, additional field sampling is needed to constrain and improve these estimates and also to assess the potential variability present.