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作 者 ：傅民杰^1,2;王传宽¹;王颖¹;刘实¹;丁爽¹

期 刊 ：应用生态学报 2009年 20卷 07期 页码：1635-1642

关键词：落叶松；

摘 要 ：春季解冻期北方森林土壤释放出大量的N₂O，是大气温室气体的主要来源之一.本研究将分布于塔河(52°31′ N)、松岭(50°43′ N)、孙吴（49°13′ N）和带岭（47°05′ N）4个纬度上林分状况相似的兴安落叶松林样地（包括幼树、地被物和A、B层土壤）移置至其自然分布区南缘,模拟气候暖化，分析春季解冻期土壤N2O通量的时间动态及其影响因子.结果表明：各处理的土壤N2O释放高峰均出现在解冻中后期.带岭、孙吴、松岭和塔河样地土壤解冻期的土壤N₂O平均通量分别为（66.5±9.3）、（54.3±5.6）、（44.3±5.3）和（33.5±3.7） μg·m^-2·h^-1;土壤N₂O通量与5 cm土壤温度和0～10 cm土壤微生物生物量碳呈显著正相关，但与土壤含水率的相关性不显著.解冻期4个处理的土壤N₂O释放差异显著，其平均通量和累积释放量均随纬度升高而下降.这种差异主要是由于不同纬度土壤的微生物活性和土壤物理性质的差异引起的.

Abstract:During the soil thawing period in spring, large amount of N2O was emitted from
the forest soils in North China, being a major source of atmospheric greenhouse
gases. However, the contribution of the emitted N2O and its responses t
o climatic change are unclear. In this paper, sampling plots of Larix gmelinii
 f
orest (including sapling, ground vegetation, and soil A and B horizons) with sim
ilar stand conditions in Tahe (52°31′ N), Songling (50°43′ N), Sunwu (49°13′ N),
and Dailing (47°05′ N) were displaced to the south boundary of L. gmelinii
natural distribution area to simulate that the plots were under climate warming,
and their N2O fluxes were measured during the soil thawing period in spring 2
007. For the four plots, the N2O fluxes all peaked at the mid- or late stage
of soil thawing. The N2O flux of the plots from Dailing, Suwu, Songling, and T
ahe during soil thawing period was averagely 665±93, 543±56, 443±53, and 335±37 μg
·m-2·h-1, respectively, and significantly positively correlated to
the soil temperature at 5 cm depth and the soil microbial biomass carbon at 0
〖KG-*2〗-〖KG-*7〗1
0 cm depth. No significant relationship was observed between the N2O flux and
soil moisture content. The soil N2O emission during soil thawing period differ
ed significantly among the plots. Both the mean N2O flux and the cumulative N
2O emission decreased with increasing latitude, mainly due to the differences
in soil microbial activities and soil physical properties.

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