![Land use effects on gross nitrogen mineralization, nitrification, and N"2O emissions in ephemeral wetlands [An article from: Soil Biology and Biochemistry]](https://www.ebooknetworking.net/books/B00/0PA/bigB000PAUXMK.jpg)
Land use effects on gross nitrogen mineralization, nitrification, and N"2O emissions in ephemeral wetlands [An article from: Soil Biology and Biochemistry]
Description
This digital document is a journal article from Soil Biology and Biochemistry, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
Stable ^1^5N isotope dilution and tracer techniques were used in cultivated (C) and uncultivated (U) ephemeral wetlands in central Saskatchewan, Canada to: (1) quantify gross mineralization and nitrification rates and (2) estimate the relative proportion of N"2O emissions from these wetlands that could be attributed to denitrification versus nitrification-related processes. In-field incubation experiments were repeated in early May, mid-June and late July. Mean gross mineralization and nitrification rates (10.3 and 3.1mgkg^-^1d^-^1, respectively) did not differ between C and U wetlands on any given date. Despite these similarities, the mean NH"4^+ pool size in the U wetlands (17.2mgkg^-^1) was two to three times that of the C wetlands (6.7mgkg^-^1) whereas the mean NO"3^- pool size in U wetlands (2.2mgkg^-^1) was less than half that of C wetlands (5.8mgkg^-^1). Mean N"2O emissions from the C wetlands decreased from 112.8 to 17.0ngN"2Om^2s^-^1 from May to July, whereas mean U-wetland N"2O emissions ranged only from 31.8 to 51.1ngN"2Om^2s^-^1 over the same period. This trend is correlated to water-filled pore space in C wetlands, demonstrating a soil moisture influence on emissions. Denitrification is generally considered the dominant emitter of N"2O under anaerobic conditions, but in the C wetlands, only 49% of the May emissions could be directly attributed to denitrification, decreasing to 29% in July. In contrast, more than 75% of the N"2O emissions from the U wetlands arose from denitrification of the soil NO"3^- pool throughout the season. These land use differences in emission sources and rates should be taken into consideration when planning management strategies for greenhouse gas mitigation.
Description:
Stable ^1^5N isotope dilution and tracer techniques were used in cultivated (C) and uncultivated (U) ephemeral wetlands in central Saskatchewan, Canada to: (1) quantify gross mineralization and nitrification rates and (2) estimate the relative proportion of N"2O emissions from these wetlands that could be attributed to denitrification versus nitrification-related processes. In-field incubation experiments were repeated in early May, mid-June and late July. Mean gross mineralization and nitrification rates (10.3 and 3.1mgkg^-^1d^-^1, respectively) did not differ between C and U wetlands on any given date. Despite these similarities, the mean NH"4^+ pool size in the U wetlands (17.2mgkg^-^1) was two to three times that of the C wetlands (6.7mgkg^-^1) whereas the mean NO"3^- pool size in U wetlands (2.2mgkg^-^1) was less than half that of C wetlands (5.8mgkg^-^1). Mean N"2O emissions from the C wetlands decreased from 112.8 to 17.0ngN"2Om^2s^-^1 from May to July, whereas mean U-wetland N"2O emissions ranged only from 31.8 to 51.1ngN"2Om^2s^-^1 over the same period. This trend is correlated to water-filled pore space in C wetlands, demonstrating a soil moisture influence on emissions. Denitrification is generally considered the dominant emitter of N"2O under anaerobic conditions, but in the C wetlands, only 49% of the May emissions could be directly attributed to denitrification, decreasing to 29% in July. In contrast, more than 75% of the N"2O emissions from the U wetlands arose from denitrification of the soil NO"3^- pool throughout the season. These land use differences in emission sources and rates should be taken into consideration when planning management strategies for greenhouse gas mitigation.
