Soil organic carbon and nitrogen content of density fractions and effect of meadow degradation to soil carbon and nitrogen of fractions in alpine Kobresia meadow
Soil organic carbon and nitrogen content of density fractions and effect of meadow degradation to soil carbon and nitrogen of fractions in alpine Kobresia meadow
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高寒嵩草草甸密度组分土壤有机碳、氮含量及草甸退化对各组分土壤碳、氮的影响
DOI：
10.1007/s11430-009-0056-5
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发表时间：
2009-05
期刊：
影响因子：
--
通讯作者：
Wang, WenYing
中科院分区：
文献类型：
--
作者：
Wang, QiJi;Lu, ZiYu;Wang, WenYing
对青海省达日县未受干扰的天然高寒嵩草草甸（YF）和严重退化草甸（SDL）进行研究。采用密度分级法，将每个土壤样品分为两个组分：轻组分（LF）和重组分（HF）。分析所获得的级分的有机碳（OC）和氮（N）浓度。结果显示：（1）在0-10 cm深度，HF和LF中OC含量分别为3.84%和28.63%，而N含量分别为0.362%和1.192%。碳氮比HF为10.6，LF为23.8。(2)就有机碳在总样品中所占比例而言，在整个土壤剖面中，有机碳在HF中的优势明显。随着深度的增加，HF的OC从78.95%增加到90.33%，而LF的OC从21.05%下降到9.68%。(3)土壤有机碳总量在YF为47.47 g · kg-1，在SDL为17.63 g · kg-1，其中HF为37.31 g · kg-1，LF为10.01 g·kg-1。也就是说，草地退化导致了高寒草甸原始生态系统中HF和LF的有机碳分别损失了57%和84%。此外，草甸退化导致了高寒草甸原生态系统中HF和LF中N的损失，分别为43%和79%。(4)草地退化过程中LF碳、氮损失的主要原因不是LF和LF中OC和N含量的降低，而是LF干重的降低。HF中N的损失远低于C的损失。这可能提示HF时C和N的保护模式存在差异。
This research was conducted on the non-disturbed native alpine Kobresia meadow (YF) and the severely degraded meadow (SDL) of Dari County of Qinghai Province. By a density fractionation approach, each soil sample was divided into two fractions: light fraction (LF) and heavy fraction (HF). The obtained fractions were analyzed for organic carbon (OC) and nitrogen (N) concentrations. The results showed: (1) the OC concentration in HF and LF was 3.84% and 28.63% respectively while the nitrogen concentration in HF and LF was 0.362% and 1.192% respectively in 0–10 cm depth. C:N ratio was 10.6 in HF and 23.8 in LF respectively. (2) As far as the ratio of OC in given fraction to that in gross sample was concerned, dominance of OC in HF was obvious in the whole soil profile. OC in HF increased from 78.95% to 90.33%, while OC in LF decreased from 21.05% to 9.68% with depths. (3) Soil total OC amounted to 47.47 in YF while 17.63 g · kg−1 in SDL, in which the OC content in HF decreased from 37.31 to 16.01 g · kg−1 while OC content in LF decreased from 10.01 to 1.62 g · kg−1. In other words, results of OC and N content show meadow degradation led to the loss of 57% OC in HF and 84% OC in LF from originally native ecosystem on alpine meadow. In addition, meadow degradation led to the loss of 43% N in HF and 79% N in LF from originally native ecosystem on alpine meadow. (4) The main reason for loss of C and N in LF during meadow degradation was not attributed to the decrease of OC and N concentration in LF and LF, but to the decrease in LF dry weight. Loss of N was far lower than loss of C in HF. This may suggest that there is difference in protection mode of C and N in HF.
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DOI：
10.5860/choice.31-3799
发表时间：
2013-01
期刊：
--
影响因子：
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作者：
S. Pal
通讯作者：
S. Pal
影响因子：
--
作者：
Wang Qi-ji;W. Wenying;Jing Zeng-chun;W. Gang
通讯作者：
Wang Qi-ji;W. Wenying;Jing Zeng-chun;W. Gang
影响因子：
1.7
作者：
E. Bremer;H. Janzen;A. Johnston
通讯作者：
E. Bremer;H. Janzen;A. Johnston
DOI：
10.2136/sssaj1995.03615995005900060018x
发表时间：
1995-11
影响因子：
2.9
作者：
J. Hassink
通讯作者：
J. Hassink
DOI：
10.5860/choice.33-2731
发表时间：
1995-05
期刊：
--
影响因子：
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作者：
R. Lal
通讯作者：
R. Lal