A comparison of soil organic carbon stocks between residential turf grass and native soil

Abstract

A central principle in urban ecological theory implies that in urbanized landscapes anthropogenic drivers will dominate natural drivers in the control of soil organic carbon storage (SOC). To assess the effect of urban land-use change on the storage of SOC, we compared SOC stocks of turf grass and native cover types of two metropolitan areas (Baltimore, MD, and Denver, CO) representing climatologically distinct regions in the United States. We hypothesized that introducing turf grass and management will lead to higher SOC densities in the arid Denver area and lower densities in the mesic Baltimore area relative to native cover types. Moreover, differences between turf grass soils will be less than differences between the native soils of each metropolitan region. Within Baltimore, turf grass had almost a 2-fold higher SOC density at 0-to 1-m and 0-to 20-cm depths than in rural forest soils, whereas there were no differences with soils of urban forest remnants. Moreover, urban forest remnants had more than 70% higher SOC densities than rural forest soils. Within Denver, turf grass (>25 years of age) had more than 2-fold higher SOC densities than in shortgrass steppe soils, while having similar densities to Baltimore turf grass soils. By contrast, the native soils of Baltimore were almost 2-fold higher than the native steppe grass soils of Denver using SOC densities of remnant forests as representative of native soils in the Baltimore region. These results supported our hypothesis that turf grass systems will be similar in SOC densities across regional variations in climate, parent material, and topography. These similarities are apparently due to greater management efforts in the Denver region to offset the constraint of climate, i.e., anthropogenic factors (management supplements) overwhelmed native environmental factors that control SOC storage.

Vegetation Type and Age Drive Changes in Soil Properties, Nitrogen, and Carbon Sequestration in Urban Parks under Cold Climate

“…The SOC sequestered by urban greenspace soils at lower latitudes range between 2 and 18 kg m −2 (Golubiewski, 2006;Pouyat et al, 2006Pouyat et al, , 2009Edmondson et al, 2014b;Livesley et al, 2016). Given the large variation in sampling depths among these studies, comparing our results to others is not straightforward.…”

“…The longer plants and soil interact, the stronger the coupling between the two in the rhizosphere (De Deyn et al, 2008) and the more likely the plant driven phenomena to manifest in the soil (Wardle, 2002). In urban systems, old soils, mostly home-yard lawns, may sequester more C and N than recently established home-yards (Qian and Follett, 2002;Frank et al, 2006;Golubiewski, 2006;Pouyat et al, 2009;Raciti et al, 2011). Little information is available on the impacts of vegetation or park age, other than for grasses/lawns, on C and N sequestration in urban greenspace soils.…”

Managing soil carbon stocks to enhance the resilience of urban ecosystems

“…The area-weighted SOC stock to 100-cm depth of urban soils in Baltimore, MD, was 71.1 Mg C ha -1 ranging between 105 and 121 Mg C ha -1 for remnant forests and turf grass sites, respectively (Table 2; Pouyat et al, 2009). However, across the city it was assumed that urban soils beneath impervious and unsealed surfaces stored 33.0 and 110.0 Mg C ha -1 to 100-cm depth, respectively.. Further, residential turf grass soils stored more SOC to 100-cm depth than rural forest soils (110 vs. 67 Mg C ha -1 )..…”

Assessing the homogenization of urban land management with an application to US residential lawn care

“…refs. [8][9][10]. The composition of plant species, soil nutrient profiles, and presence or extent of surface water bodies appears to be increasingly similar across cities, even in dissimilar biophysical settings (10)(11)(12)(13)(14).…”