|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|5750601||1412497||2017||5 صفحه PDF||سفارش دهید||دانلود کنید|
- Long-term P addition enhanced DOC biodegradation in an N-limited temperate wetland.
- Long-term P addition decreased DOC:DTN ratio and SUVA254 in this wetland.
- DOC biodegradation was negatively correlated with DOC:DTN ratio and SUVA254, respectively.
- Enhanced DOC biodegradation would cause DOC loss from the waters in temperate wetlands.
Phosphorus (P) enrichment is expected to strongly influence dissolved organic carbon (DOC) biodegradation. However, the relationship between P availability and DOC biodegradation is largely unknown in nitrogen (N)-limited ecosystems. Here, we investigated the changes in the ratio of DOC to dissolved total nitrogen (DTN), specific UV absorbance at 254Â nm (SUVA254), and DOC biodegradation in surface water and soil pore water (0-15Â cm depth) following eight years of multi-level P addition (0, 1.2, 4.8, and 9.6Â gÂ PÂ mâÂ 2Â yearâÂ 1) in an N-limited freshwater marsh in Northeast China. We found that P addition caused an increase in DOC biodegradation in surface water and soil pore water, irrespective of the P addition levels. Compared with the control treatment, the P addition rates of 1.2, 4.8, and 9.6Â gÂ PÂ mâÂ 2Â yearâÂ 1 increased DOC biodegradation by 20.7%, 15.2%, and 14.5% in surface waters, and 11.3%, 9.4%, and 12.0% in soil pore waters, respectively. The DOC biodegradation was separately negatively correlated with the DOC:DTN ratio and SUVA254, indicating that the positive effect of P addition on DOC biodegradation was caused by the elevated N concentration and the reduced DOC aromaticity. Our findings suggest that P enrichment enhances the biodegradability of DOC through increased N availability and altered DOC chemical composition, which would accelerate DOC loss from the waters and alter ecosystem C balance in N-limited temperate wetlands.
Journal: Science of The Total Environment - Volumes 605â606, 15 December 2017, Pages 332-336