کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2025666 | 1070005 | 2008 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Mechanisms of short-term soil carbon storage in experimental grasslands Mechanisms of short-term soil carbon storage in experimental grasslands](/preview/png/2025666.png)
We investigated the fate of root and litter derived carbon in soil organic matter and dissolved organic matter in soil profiles, in order to explain mechanisms of short-term soil carbon storage. A time series of soil and soil solution samples was investigated at the field site of The Jena Experiment between 2002 and 2004. In addition to the main experiment with C3 plants, a C4 species (Amaranthus retroflexus L.) naturally labeled with 13C was grown on an extra plot. Changes in organic carbon concentration in soil and soil solution were combined with stable isotope measurements to follow the fate of plant carbon into the soil and soil solution. A split plot design with plant litter removal versus double litter input simulated differences in biomass input. After 2Â years, the no litter and double litter treatment, respectively, showed an increase of 381Â g CÂ mâ2 and 263Â g CÂ mâ2 to 20Â cm depth, while 71Â g CÂ mâ2 and 393Â g CÂ mâ2 were lost between 20 and 30Â cm depth. The isotopic label in the top 5Â cm indicated that 115Â g CÂ mâ2 and 156Â g CÂ mâ2 of soil organic carbon were derived from C4 plant material on the no litter and the double litter treatment, respectively. Without litter, this equals the total amount of 97Â g CÂ mâ2 that was newly stored in the same soil depth, whereas with double litter this clearly exceeded the stored amount of 75Â g CÂ mâ2. Our results indicate that litter input resulted in lower carbon storage and larger carbon losses and consequently accelerated turnover of soil organic carbon. Isotopic evidence showed that inherited soil organic carbon was replaced by fresh plant carbon near the soil surface. Our results suggest that primarily carbon released from soil organic matter, not newly introduced plant organic matter, was transported in the soil solution. However, the total flow of dissolved organic carbon was not sufficient to explain the observed carbon storage in deeper soil layers, and the existence of additional carbon uptake mechanisms is discussed.
Journal: Soil Biology and Biochemistry - Volume 40, Issue 10, October 2008, Pages 2634-2642