Patterns of SOC and soil 13C and their relations to climatic factors and soil characteristics on the Qinghai–Tibetan Plateau
Patterns of SOC and soil 13C and their relations to climatic factors and soil characteristics on the Qinghai–Tibetan Plateau
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DOI：
10.1007/s11104-012-1304-6
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发表时间：
2013-02
期刊：
影响因子：
4.9
通讯作者：
Shaoqiang Wang;Jiangwen Fan;Minghua Song;Guirui Yu;Lei Zhou;Jiyuan Liu;H. Zhong;Lu-peng Gao;Zhongmin Hu;Weixing Wu;Tingting Song
中科院分区：
文献类型：
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作者：
Shaoqiang Wang;Jiangwen Fan;Minghua Song;Guirui Yu;Lei Zhou;Jiyuan Liu;H. Zhong;Lu-peng Gao;Zhongmin Hu;Weixing Wu;Tingting Song
背景与目的土壤有机碳清单和土壤δ13C被广泛用于获取土壤碳库的大小，并指示碳输入和输出的动态。为了更好地了解青藏高原生态系统碳循环动态，分析了气候因素、土壤物理特性和植物凋落物输入对土壤有机碳清单和土壤δ13C的影响。结果表明，森林、草甸、草原和农田土壤有机碳密度明显高于草原和青稞。而林地和草甸的δ-13C低于草原和青稞。随着土壤深度的增加，土壤δ~(13)C趋于丰富，而有机碳则呈下降趋势。不同生态系统中SOC和δ13C(0~40 cm)与不同气候因子相关，表现为草甸SOC与MAT呈负相关，草原与MAP呈正相关，草甸和草原δ13C与MAT呈正相关，δ13C也有随森林MAT增加而增加的趋势。在土壤有机碳的变化中，55.15%是由MAP、pH和泥沙含量解释的，4.63%是由除农田以外的所有生态系统的MAT和pH的相互作用来解释的。同时，土壤有机碳密度解释了土壤δ13C变异的27.40%。结论青藏高原不同生态系统土壤碳库的大小受不同的气候因素控制。土壤有机碳密度是土壤δ~(13)C变化的关键因素。
Background and aimsSOC inventory and soil δ13C were widely used to access the size of soil C pool and to indicate the dynamics of C input and output. The effects of climatic factors and soil physical characteristics and plant litter input on SOC inventory and soil δ13C were analyzed to better understand the dynamics of carbon cycling across ecosystems on the Qinghai-Tibetan Plateau.MethodsField investigation was carried out along the two transects with a total of 1,875 km in length and 200 km in width. Sixty-two soil profiles, distributed in forest, meadow, steppe, and cropland, were stratified sampled every 10 cm from 0 to 40 cm.ResultsOur result showed that SOC density in forest and meadows were much higher than in steppe and highland barley. In contrast, δ13C in forest and meadow were lower than in steppe and highland barley. Soil δ13C tended to enrich with increasing soil depth but SOC decline. SOC and δ13C (0–40 cm) were correlated with different climatic factors in different ecosystems, such that SOC correlated negatively with MAT in meadow and positively with MAP in steppe; δ13C correlated positively with MAT in meadow and steppe; and δ13C also tended to increase with increasing MAT in forest. Of the variation of SOC, 55.15 % was explained by MAP, pH and silt content and 4.63 % was explained by the interaction between MAT and pH across all the ecosystems except for the cropland. Meanwhile, SOC density explained 27.40 % of variation of soil δ13C.ConclusionsIt is suggested that different climatic factors controlled the size of the soil C pool in different ecosystems on the Tibetan Plateau. SOC density is a key contributor to the variation of soil δ13C.