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Water, Air, & Soil Pollution - Heavy metal contents and concentrations of forest floor and mineral soil were determined in nine oak stands situated along an urban-rural gradient. Twelve... 相似文献
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Variation in quality and decomposability of red oak leaf litter along an urban-rural gradient 总被引:6,自引:0,他引:6
M. M. Carreiro K. Howe D. F. Parkhurst R. V. Pouyat 《Biology and Fertility of Soils》1999,30(3):258-268
This study tested whether urban land use can affect the chemistry and decomposability of Quercus rubra L. (red oak) leaf litter in forests within and near a large metropolitan area. Cities may affect the quality of leaf litter
directly through foliar uptake of atmospheric pollutants, and indirectly through alterations in local climate and changes
in soil fertility caused by pollutant loads and altered nutrient cycling regimes. Using a microbial bioassay, we tested whether
red oak leaf litter collected from urban and suburban forests in and near New York City differed in decomposability from litter
of the same species collected from rural forests 130 km from the city. We found that oak litter from the urban forests decayed
25% more slowly and supported 50% less cumulative microbial biomass in a laboratory bioassay than rural litter. Rural litter
contained less lignin and more labile material than urban litter, and the amounts of these chemical constituents were highly
correlated with the decay rate coefficients and integrated microbial growth achieved on the litter. The specific causes of
the variation in litter chemistry are not known. The results of this study suggest that decomposer activity and nutrient cycling
in forests near large cities may be affected both by altered litter quality and by altered biotic, chemical and physical environments.
The sensitivity of the microbial bioassay makes it useful for distinguishing differences in within-species litter quality
that result from natural or anthropogenic variation in the environment.
Received: 7 January 1999 相似文献
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Landscape Ecology - Soil heterogeneity versus homogeneity patterns are observed within and across urban landscapes at multiple scales. To fully evaluate human-mediated influences on soil properties... 相似文献
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Response of forest soil properties to urbanization gradients in three metropolitan areas 总被引:2,自引:0,他引:2
Richard V. Pouyat Ian D. Yesilonis Katalin Szlavecz Csaba Csuzdi Elizabeth Hornung Zoltan Korsós Jonathan Russell-Anelli Vincent Giorgio 《Landscape Ecology》2008,23(10):1187-1203
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. 相似文献
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