کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2026502 | 1070032 | 2005 | 10 صفحه PDF | دانلود رایگان |
The short-term pulse of carbon (C) and nitrogen (N) mineralization that accompanies the wetting of dry soils may dominate annual C and N production in many arid and semi-arid environments characterized by seasonal transitions. We used a laboratory incubation to evaluate the impact of short-term fluctuations in soil moisture on long-term carbon and nitrogen dynamics, and the degree to which rewetting enhances C and N release. Following repeated drying and rewetting of chaparral soils, cumulative CO2 release in rewet soils was 2.2–3.7 times greater than from soils maintained at equivalent mean soil moisture and represented 12–18% of the total soil C pool. Rewetting frequency did not affect cumulative CO2 release but did enhance N turnover, and net N mineralization and nitrification increased with rewetting in spite of significant reductions in nitrification potential. Litter addition decreased inorganic N release but enhanced dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) from dry soils, indicating the potential importance of a litter-derived pulse to short-term nutrient dynamics.
Journal: Soil Biology and Biochemistry - Volume 37, Issue 12, December 2005, Pages 2195–2204