Department of Plant and Soil Sciences, University of Delaware, 152 Townsend Hall, Newark, Delaware, 19716, USA.
USDA Forest Service, 1400 Independence Avenue NW, Washington, D.C., 20250, USA.
Ecol Appl. 2017 Apr;27(3):991-1000. doi: 10.1002/eap.1502. Epub 2017 Mar 16.
Soils constitute the largest sink of terrestrial carbon (C), and urban soils have the potential to provide significant soil C storage. Soils in urbanized landscapes experience a multitude of human alterations, such as compaction and management subsidies, that impact soil C dynamics. While field studies may provide data on urban soil C storage, modeling soil C dynamics under various human impact scenarios will provide a basis for identifying drivers of urban soil C dynamics and for predicting the potential for these highly altered soils to store C over time intervals not typically amenable to empirical validation. The goal of this study was to model soil C dynamics in residential lawns using CENTURY, a dynamic mechanistic model, to determine whether drivers of soil C dynamics in natural systems (e.g., soil texture) were equally useful for estimating soil C content of highly modified soils in urban residential areas. Without incorporating human impacts, we found no relationship between initial CENTURY model simulations and observed soil C (P > 0.05). Factors that best explained soil C accumulation for the observed soil C (bulk density, r = 0.30; home age, r = 0.37; P < 0.01) differed from those found important for the CENTURY model simulations (percent sand, r = 0.72, P < 0.001). Therefore, we conducted a modeling exercise to test whether simulating potential construction disturbance and lawn management practices would improve modeled soil and tree C. We found that incorporating these factors did improve CENTURY's ability to model soil and tree C (P < 0.001). The results from this analysis suggest that incorporating various human disturbances and management practices that occur in urban landscapes into CENTURY model runs will improve its ability to predict urban soil C dynamics, at least within a 100-yr time frame. Thus, enhancing our ability to provide recommendations for management and development practices that result in increasing urban soil C storage.
土壤是陆地碳（C）的最大汇，城市土壤具有提供显著土壤 C 储存的潜力。城市化景观中的土壤经历了多种人为改变，如压实和管理补贴，这些改变会影响土壤 C 动态。虽然野外研究可能提供有关城市土壤 C 储存的数据，但模拟各种人为影响情景下的土壤 C 动态将为确定城市土壤 C 动态的驱动因素以及预测这些高度改变的土壤在通常无法进行实证验证的时间间隔内储存 C 的潜力提供基础。本研究的目的是使用 CENTURY 模型模拟住宅草坪的土壤 C 动态，以确定自然系统中土壤 C 动态的驱动因素（例如土壤质地）是否同样可用于估算城市住宅区高度改性土壤的土壤 C 含量。在不考虑人为影响的情况下，我们发现初始 CENTURY 模型模拟与观测到的土壤 C 之间没有关系（P>0.05）。对观测到的土壤 C 最能解释土壤 C 积累的因素（体密度，r=0.30；房屋年龄，r=0.37；P<0.01）与对 CENTURY 模型模拟发现的重要因素（砂百分比，r=0.72，P<0.001）不同。因此，我们进行了建模练习以测试模拟潜在的施工干扰和草坪管理实践是否会改善模型化的土壤和树木 C。我们发现，纳入这些因素确实可以提高 CENTURY 模型模拟土壤和树木 C 的能力（P<0.001）。这项分析的结果表明，将城市景观中发生的各种人为干扰和管理实践纳入 CENTURY 模型运行中，将提高其预测城市土壤 C 动态的能力，至少在 100 年的时间框架内是如此。因此，增强了我们为增加城市土壤 C 储存而提供管理和开发实践建议的能力。
