摘要
沙丘固定过程中土壤铵态氮和硝态氮存在着时空变化。本文对腾格里沙漠和毛乌素沙地沙丘固定过程中土壤铵态氮和硝态氮的含量进行了测定。结果表明,在剖面的垂直方向,土壤铵态氮和硝态氮含量均随土壤深度的增加而减小;在沙丘的水平方向,从丘顶、丘坡到丘间地,土壤铵态氮和硝态氮含量均趋于增加,但20～40cm土层的硝态氮/铵态氮比(硝/铵比)逐渐降低。而其时间变化体现于演替系列的进程中,演替系列前中期,土壤铵态氮含量逐渐增加,演替系列中后期,硝态氮含量逐渐增加;0～20cm土层硝/铵比的变化与上述趋势相同,而20～40cm土层硝/铵比的变化则没有这种规律。可见,在沙丘固定过程中,土壤铵态氮和硝态氮均表现出明显的时空变化规律,这种时空变化规律是植被与环境综合作用的结果,进而影响植物生长与植被动态。
Temporal-spatial variations of soil NH4＋-N and NO3--N exists in sand dune fixing process. Contents of soil NH4＋-N and NO3--N in sand dunes of the Tengger Desert and the Mu Us Sandy Land were measured. Results show that vertically the content of N of either form decreased with the depth along soil profiles; while horizontally,from the top to the slope and the foot of a dune,both increased gradually,but the NH4＋-N/NO3--N ratio in the depth of 20～40 cm decreased gradually. And their temporal variations were reflected in the succession series of plant community. The content of NH4＋-N in the soil increased gradually from the prophase to the metaphase of the series,while the content of NO3--N in the soil did from the metaphase to the anaphase of the series. The NH4＋-N/NO3--N ratio in the depth of 0～20 cm showed a similar trend,while that in the depth of 20～40 cm did not. Such a pattern of temporal-spatial variation of soil NH4＋-N and NO3--N was reflected in the fixing process of sand dunes,and was a result of the integrated effect of vegetation and environment,and in turn affected plant growth and vegetation dynamics.
出处
《土壤学报》
CAS
CSCD
北大核心
2010年第2期295-302,共8页
Acta Pedologica Sinica
基金
国家重点基础研究发展计划项目(2009CB421303)资助
关键词
土壤
铵态氮
硝态氮
沙丘固定
植被动态
Soil NH4＋-N NO3--N Fixation of sand dune Vegetation dynamics
