文章基本信息

标题：Nitrogen isotopic signatures and fluxes of N 2 O in response to land-use change on naturally occurring saline–alkaline soil
本地全文：下载
作者：Arbindra Timilsina ; Wenxu Dong ; Jiafa Luo 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2020
卷号：10
期号：1
页码：1-13
DOI：10.1038/s41598-020-78149-w
出版社：Springer Nature
摘要：The conversion of natural grassland to semi-natural or artificial ecosystems is a large-scale land-use change (LUC) commonly occurring to saline–alkaline land. Conversion of natural to artificial ecosystems, with addition of anthropogenic nitrogen (N) fertilizer, influences N availability in the soil that may result in higher N2O emission along with depletion of 15N, while converting from natural to semi-natural the influence may be small. So, this study assesses the impact of LUC on N2O emission and 15N in N2O emitted from naturally occurring saline–alkaline soil when changing from natural grassland (Phragmites australis) to semi-natural [Tamarix chinensis (Tamarix)] and to cropland (Gossypium spp.). The grassland and Tamarix ecosystems were not subject to any management practice, while the cropland received fertilizer and irrigation. Overall, median N2O flux was significantly different among the ecosystems with the highest from the cropland (25.3 N2O-N µg m−2 h−1), intermediate (8.2 N2O-N µg m−2 h−1) from the Tamarix and the lowest (4.0 N2O-N µg m−2 h−1) from the grassland ecosystem. The 15N isotopic signatures in N2O emitted from the soil were also significantly affected by the LUC with more depleted from cropland (− 25.3 ‰) and less depleted from grassland (− 0.18 ‰). Our results suggested that the conversion of native saline–alkaline grassland with low N to Tamarix or cropland is likely to result in increased soil N2O emission and also contributes significantly to the depletion of the 15N in atmospheric N2O, and the contribution of anthropogenic N addition was found more significant than any other processes.
其他摘要：Abstract The conversion of natural grassland to semi-natural or artificial ecosystems is a large-scale land-use change (LUC) commonly occurring to saline–alkaline land. Conversion of natural to artificial ecosystems, with addition of anthropogenic nitrogen (N) fertilizer, influences N availability in the soil that may result in higher N 2 O emission along with depletion of 15 N, while converting from natural to semi-natural the influence may be small. So, this study assesses the impact of LUC on N 2 O emission and 15 N in N 2 O emitted from naturally occurring saline–alkaline soil when changing from natural grassland (Phragmites australis) to semi-natural [ Tamarix chinensis (Tamarix)] and to cropland ( Gossypium spp.). The grassland and Tamarix ecosystems were not subject to any management practice, while the cropland received fertilizer and irrigation. Overall, median N 2 O flux was significantly different among the ecosystems with the highest from the cropland (25.3 N 2 O-N µg m −2 h −1 ), intermediate (8.2 N 2 O-N µg m −2 h −1 ) from the Tamarix and the lowest (4.0 N 2 O-N µg m −2 h −1 ) from the grassland ecosystem. The 15 N isotopic signatures in N 2 O emitted from the soil were also significantly affected by the LUC with more depleted from cropland (− 25.3 ‰) and less depleted from grassland (− 0.18 ‰). Our results suggested that the conversion of native saline–alkaline grassland with low N to Tamarix or cropland is likely to result in increased soil N 2 O emission and also contributes significantly to the depletion of the 15 N in atmospheric N 2 O, and the contribution of anthropogenic N addition was found more significant than any other processes.