<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author><author><style face="normal" font="default" size="100%">Golubiewski, N. E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A comparison of soil organic carbon stocks between residential turf grass and native soil</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><edition><style face="normal" font="default" size="100%">February 21, 2009</style></edition><volume><style face="normal" font="default" size="100%">12</style></volume><pages><style face="normal" font="default" size="100%">45-62</style></pages><isbn><style face="normal" font="default" size="100%">1083-8155 (Print) 1573-1642 (Online)</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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 (&gt;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.</style></abstract><issue><style face="normal" font="default" size="100%">1 Special Issue on Soils</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2009-85663</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Williams, C. O.</style></author><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Band, L. E.</style></author><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Nitrate leaching and nitrous oxide flux in urban forests and grasslands</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><edition><style face="normal" font="default" size="100%">23 July 2009</style></edition><volume><style face="normal" font="default" size="100%">38</style></volume><pages><style face="normal" font="default" size="100%">1848-1860</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Urban landscapes contain a mix of land-use types with different patterns of nitrogen (N) cycling and export. We measured nitrate (NO3–) leaching and soil:atmosphere nitrous oxide (N2O) flux in four urban grassland and eight forested long-term study plots in the Baltimore, Maryland metropolitan area. We evaluated ancillary controls on these fluxes by measuring soil temperature, moisture, and soil:atmosphere fluxes of carbon dioxide on these plots and by sampling a larger group of forest, grass, and agricultural sites once to evaluate soil organic matter, microbial biomass, and potential net N mineralization and nitrification. Annual NO3– leaching ranged from 0.05 to 4.1 g N m–2 yr–1 and was higher in grass than forest plots, except in a very dry year and when a disturbed forest plot was included in the analysis. Nitrous oxide fluxes ranged from 0.05 to &gt;0.3 g N m–2 yr–1, with few differences between grass and forest plots and markedly higher fluxes in wet years. Differences in NO3– leaching and N2O flux between forests and grasslands were not as high as expected given the higher frequency of disturbance and fertilization in the grasslands. Carbon dioxide flux, organic matter, and microbial biomass were as high or higher in urban grasslands than in forests, suggesting that active carbon cycling creates sinks for N in vegetation and soil in these ecosystems. Although urban grasslands export more N to the environment than native forests, they have considerable capacity for N retention that should be considered in evaluations of land-use change.</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2009-85627</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author><author><style face="normal" font="default" size="100%">James, B. R.</style></author><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Momen, B.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Lead forms in urban turf grass and forest soils as related to organic matter content and pH</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><edition><style face="normal" font="default" size="100%">5 December 2007</style></edition><volume><style face="normal" font="default" size="100%">146</style></volume><pages><style face="normal" font="default" size="100%">1-17</style></pages><isbn><style face="normal" font="default" size="100%">0167-6369 (Print) 1573-2959 (Online)</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Soil pH may influence speciation and extractability of Pb, depending on type of vegetation in urban soil environments. We investigated the relationship between soil pH and Pb extractability at forest and turf grass sites in Baltimore, Maryland. Our two hypotheses were: (1) due to lower pH values in forest soils, more Pb will be in exchangeable forms in forested than in turfgrass soils and (2) due to the greater lability of exchangeable Pb in equilibrium with soil solution in forest soils, concentrations of this form will increase with depth more so than in the turfgrass soils, as related to organic matter content and pH. Soil samples were collected from three forested and three turfgrass sites to depths of 20 cm. Lead forms were determined using a sequential extraction technique. Soils under turfgrass and forest vegetation differed in the extractability of soil Pb (P?&lt;?0.01) for the Mn(III, IV)- and Fe(III)(hydr) oxide fraction. A greater Pb concentration was bound to this fraction under turfgrass (211 mg kg?1, 69% of total Pb) than forested soils (67 mg kg?1, 61% of total Pb), perhaps due to soil pH differences of 5.9 and 5.0, respectively. In the forested soils, as depth increased, the ratio of exchangeable-to-total Pb increased and the ratio of organically bound Pb-to-total Pb decreased. The results suggest changes in pH and organic matter content with depth affect the extractability of Pb, and these soil properties are affected differentially by grass versus tree vegetation in the urban soils investigated.</style></abstract><issue><style face="normal" font="default" size="100%">1-3</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2008-85586</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author><author><style face="normal" font="default" size="100%">Szlavecz, K.</style></author><author><style face="normal" font="default" size="100%">Csuzdi, C.</style></author><author><style face="normal" font="default" size="100%">Hornung, E.</style></author><author><style face="normal" font="default" size="100%">Korsós, Z.</style></author><author><style face="normal" font="default" size="100%">Russell-Anelli, J.</style></author><author><style face="normal" font="default" size="100%">Giorgio, V.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Response of forest soil properties to urbanization gradients in three metropolitan areas</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><edition><style face="normal" font="default" size="100%">7 November 2008</style></edition><volume><style face="normal" font="default" size="100%">23</style></volume><pages><style face="normal" font="default" size="100%">1187-1203</style></pages><isbn><style face="normal" font="default" size="100%">0921-2973 (Print) 1572-9761 (Online)</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We investigated the effects of urban environments on the chemical properties of forest soils in the metropolitan areas of Baltimore, New York, and Budapest. We hypothesized that soils in forest patches in each city will exhibit changes in chemistry corresponding to urbanization gradients, but more strongly with various urban metrics than distance to the urban core. Moreover, differences in parent material and development patterns would differentially affect the soil chemical response in each metropolitan area. Results showed that soil chemical properties varied with measures of urban land use in all three cities, including distance to the urban core, which was an unexpected result. Moreover, the results showed that the spatial extent and amount of change was greater in New York than in Baltimore and Budapest for those elements that showed a relationship to the urbanization gradient (Pb, Cu, and to a lesser extent Ca). The spatial relationship of the soil chemical properties to distance varied from city to city. In New York, concentrations of Pb, Cu, and Ca decreased to approximately background concentrations at 75 km from the urban core. By contrast, concentrations of these elements decreased closer to the urban core in Baltimore and Budapest. Moreover, a threshold was reached at about 75% urban land use above which concentrations of Pb and Cu increased by more than twofold relative to concentrations below this threshold. Results of this study suggest that forest soils are responding to urbanization gradients in all three cities, though characteristics of each city (spatial pattern of development, parent material, and pollution sources) influenced the soil chemical response.</style></abstract><issue><style face="normal" font="default" size="100%">10 Special Issue on Applying landscape ecological principles in urban environments</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2008-85560</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Neerchal, N. K.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Spatial distribution of metals in soils in Baltimore, Maryland: role of native parent material, proximity to major roads, housing age and screening guidelines</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><edition><style face="normal" font="default" size="100%">24 July 2008</style></edition><volume><style face="normal" font="default" size="100%">156</style></volume><pages><style face="normal" font="default" size="100%">723-731</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We investigated the spatial distribution of heavy metal above-background (anthropic) contents of Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Ti, V, and Zn in Baltimore City surface soils and related these levels to potential contaminating sources. Composite soil samples (0–10 cm depth) were digested using a nitric and hydrochloric extraction technique. Slightly more than 10% of plots exceeded United States Environmental Protection Agency screening guidelines for Pb. In a principal component analysis, the first component corresponded to Co, Cr, and Fe, which are constituents of local mafic rocks. The second component corresponded to Cu, Pb, and Zn which were significantly higher within than beyond a 100 m buffer of the major roads within the city; furthermore, Pb and Zn were higher in older residential lots. Spatial distribution of metals in soils of an older US city (Baltimore) was affected by parent material, proximity to major roads, and housing age.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2008-85587</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author><author><style face="normal" font="default" size="100%">Russell-Anelli, J.</style></author><author><style face="normal" font="default" size="100%">Neerchal, N. K.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil chemical and physical properties that differentiate urban land-use and cover types</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><edition><style face="normal" font="default" size="100%">16 May 2007</style></edition><volume><style face="normal" font="default" size="100%">71</style></volume><pages><style face="normal" font="default" size="100%">1010-1019</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">3</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2007-85463</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author><author><style face="normal" font="default" size="100%">Nowak, D. J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Carbon storage by urban soils in the United States</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><volume><style face="normal" font="default" size="100%">35</style></volume><pages><style face="normal" font="default" size="100%">1566-1575</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We used data available from the literature and measurements from Baltimore, Maryland, to (i) assess inter-city variability of soil organic carbon (SOC) pools (1-m depth) of six cities (Atlanta, Baltimore, Boston, Chicago, Oakland, and Syracuse); (ii) calculate the net effect of urban land-use conversion on SOC pools for the same cities; (iii) use the National Land Cover Database to extrapolate total SOC pools for each of the lower 48 U.S. states; and (iv) compare these totals with aboveground totals of carbon storage by trees. Residential soils in Baltimore had SOC densities that were approximately 20 to 34% less than Moscow or Chicago. By contrast, park soils in Baltimore had more than double the SOC density of Hong Kong. Of the six cities, Atlanta and Chicago had the highest and lowest SOC densities per total area, respectively (7.83 and 5.49 kg m–2). On a pervious area basis, the SOC densities increased between 8.32 (Oakland) and 10.82 (Atlanta) kg m–2. In the northeastern United States, Boston and Syracuse had 1.6-fold less SOC post- than in pre-urban development stage. By contrast, cities located in warmer and/or drier climates had slightly higher SOC pools post- than in pre-urban development stage (4 and 6% for Oakland and Chicago, respectively). For the state analysis, aboveground estimates of C density varied from a low of 0.3 (WY) to a high of 5.1 (GA) kg m–2, while belowground estimates varied from 4.6 (NV) to 12.7 (NH) kg m–2. The ratio of aboveground to belowground estimates of C storage varied widely with an overall ratio of 2.8. Our results suggest that urban soils have the potential to sequester large amounts of SOC, especially in residential areas where management inputs and the lack of annual soil disturbances create conditions for net increases in SOC. In addition, our analysis suggests the importance of regional variations of land-use and land-cover distributions, especially wetlands, in estimating urban SOC pools.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.2006-85376</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Szlavecz, K.</style></author><author><style face="normal" font="default" size="100%">Placella, S. A.</style></author><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Csuzdi, C.</style></author><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Invasive earthworm species and nitrogen cycling in remnant forest patches</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><volume><style face="normal" font="default" size="100%">32</style></volume><pages><style face="normal" font="default" size="100%">54-63</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER.2006-85389</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Groffman, P.M.</style></author><author><style face="normal" font="default" size="100%">Pouyat, R. V.</style></author><author><style face="normal" font="default" size="100%">Cadenasso, M. L.</style></author><author><style face="normal" font="default" size="100%">Zipperer, W. C.</style></author><author><style face="normal" font="default" size="100%">Szlavecz, K.</style></author><author><style face="normal" font="default" size="100%">Yesilonis, I. D.</style></author><author><style face="normal" font="default" size="100%">Band, L. E.</style></author><author><style face="normal" font="default" size="100%">Brush, G. S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Land use context and natural soil controls on plant community composition and soil nitrogen and carbon dynamics in urban and rural forests</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BES</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><volume><style face="normal" font="default" size="100%">236</style></volume><pages><style face="normal" font="default" size="100%">177-192</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">2-3</style></issue><accession-num><style face="normal" font="default" size="100%">LTER.2006-85331</style></accession-num></record></records></xml>