| Autor: |
Patrick J. Bohlen, Ruth E. Sherman, Joseph B. Yavitt, Melany C. Fisk, John C. Maerz, Timothy J. Fahey, Peter M. Groffman |
| Rok vydání: |
2015 |
| Předmět: |
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| Zdroj: |
Soil Biology and Biochemistry. 87:51-58 |
| ISSN: |
0038-0717 |
| DOI: |
10.1016/j.soilbio.2015.03.025 |
| Popis: |
Earthworms have been shown to produce contrasting effects on soil carbon (C) and nitrogen (N) pools and dynamics. We measured soil C and N pools and processes and traced the flow of 13C and 15N from sugar maple (Acer saccharum Marsh.) litter into soil microbial biomass and respirable C and mineralizable and inorganic N pools in mature northern hardwood forest plots with variable earthworm communities. Previous studies have shown that plots dominated by either Lumbricus rubellus or Lumbricus terrestris have markedly lower total soil C than uncolonized plots. Here we show that total soil N pools in earthworm colonized plots were reduced much less than C, but significantly so in plots dominated by contain L. rubellus. Pools of microbial biomass C and N were higher in earthworm-colonized (especially those dominated by L. rubellus) plots and more 13C and 15N were recovered in microbial biomass and less was recovered in mineralizable and inorganic N pools in these plots. These plots also had lower rates of potential net N mineralization and nitrification than uncolonized reference plots. These results suggest that earthworm stimulation of microbial biomass and activity underlie depletion of soil C and retention and maintenance of soil N pools, at least in northern hardwood forests. Earthworms increase the carrying capacity of soil for microbial biomass and facilitate the flow of N from litter into stable soil organic matter. However, declines in soil C and C:N ratio may increase the potential for hydrologic and gaseous losses in earthworm-colonized sites under changing environmental conditions. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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