Changes in carbon and nitrogen in soil particle-size fractions along a grassland restoration chronosequence in northern China
Changes in carbon and nitrogen in soil particle-size fractions along a grassland restoration chronosequence in northern China
复制标题
中国北方草原恢复年代土壤粒径碳氮变化
DOI：
10.1016/j.geoderma.2009.02.004
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发表时间：
2009-05-15
期刊：
影响因子：
6.1
通讯作者：
Han, Xingguo
中科院分区：
文献类型：
--
作者：
He, Nianpeng;Wu, Ling;Han, Xingguo
禁牧可以增加中国半干旱草地的碳储量，但长期禁牧对土壤组分碳储量的影响尚不清楚。根据草地恢复从自由放牧到28年放牧的时间序列，研究了土壤组分中全C和全N的动态变化，以评估长期放牧对土壤组分的影响。结果表明，长期施用外源基因对土壤颗粒组成及其全C、全N含量有显著影响。0-10 cm土层中与砂和粘粒结合的碳随转基因时间的增加呈显著的对数增长。转基因植物的引入显著增加了土壤碳储量，尤其是在0-10 cm土层的砂粒和粘粒中。随着草地恢复，全土和砂、粉土的C：N比显著增加。考虑到全土和土壤组分中全碳的积累及其在GE时序中的对数增长，我们认为，通过实施GE，中国北方温带草原可以促进十年尺度上的显著C储存：然而，当遭受20年或更长时间的GE时，这些草原土壤进一步积累来自凋落物和死根的新C的潜力较低。(C)2009 Elsevier B. V.保留所有权利。
Grazing exclusion (GE) can increase the carbon (C) storage of semiarid grasslands in China; however, little is known about the effect of long-term GE on the C storage of soil fractions. On the basis of a chronosequence of grassland restoration from free grazing (FG) to 28-year GE, we investigated the dynamics of total C and N in soil fractions in order to assess the impact of long-term GE on the soil fractions. The results revealed that long-term GE had a marked impact on soil particle-size fractions and their total C and N concentrations. The C associated with sand and clay in the 0-10 cm soil layer exhibited a significant logarithmic increase as period of GE increases. The increase in C storage with the introduction of GE was considerable, especially in the sand and clay fraction of 0-10 cm soil layer. The C:N ratios of the whole soil and of the sand and silt increased significantly with grassland restoration. Considering the accumulation of total C in the whole soil and soil fractions and their logarithmic increase during the GE chronosequence, we suggest that by implementing GE, the temperate grasslands of northern China could facilitate significant C storage on decade scales: however, when subjected to GE for 2 decades or more, these grassland soils would have a lower potential to further accumulate the C newly derived from litter and dead roots. (C) 2009 Elsevier B.V. All rights reserved.