| Autor: |
Colin-belgrand, Micheline, Dambrine, Etienne, Bienaimé, Séverine, Nys, Claude, Turpault, Marie-pierre |
| Předmět: |
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| Zdroj: |
Scandinavian Journal of Forest Research. Jun2003, Vol. 18 Issue 3, p260. 9p. |
| Abstrakt: |
This study compared the total carbon (C), mineral nitrogen (N) contents and N mineralization potentials of the rhizospheric and bulk soils, collected at two depths in three forest sites in France. The site at Breuil is a comparative plantation of different species with or without fertilization, the Fougères site is a time sequence of four Fagus sylvatica L. stands including a limed plot, and the Aubure site is a comparison between adjacent young and old Picea abies. (L.) Karst stands with different nitrifying activity. Mineral N was extracted from fresh soil with K[SUB2]SO[SUB4] and after laboratory incubation at 15°C for 2 days or 1 week. The moisture, C and N contents of the rhizospheric soil were higher than in the bulk soil in the A[SUB1] horizon, but only slightly higher or similar in A[SUB1]B horizons. Soil-extractable NH[SUB4] and net mineralization were much larger in the rhizospheric soil than in the bulk soil. Soil-extractable NO[SUB3] and net nitrification were not significantly different. Soil-extractable NH[SUB4] and net N mineralization were linearly and positively related to the soil C (or N) contents, but the relationship was stronger and the amount of mineral N per gram of carbon was higher for rhizospheric soil. This suggests that the quality of rhizospheric carbon should be taken into account. Net N mineralization was negatively related to the soil C/N ratio. In summary, tree roots appear to have a strong influence on N transformation in soils. [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
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