Snow removal and its influence on temperature and N dynamics in alpine soils (Vallee d'Aoste, northwest Italy)
Snow removal and its influence on temperature and N dynamics in alpine soils (Vallee d'Aoste, northwest Italy)
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DOI：
10.1002/jpln.200700278
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发表时间：
2008-10-01
影响因子：
2.5
通讯作者：
Zanini, Ermanno
中科院分区：
文献类型：
--
作者：
Freppaz, Michele;Celi, Luisella;Zanini, Ermanno
在两种土壤中，落叶松和草甸下，在西北意大利（瓦莱德'奥斯特地区）冬季积雪覆盖的影响进行了调查。在1980年代末和1990年代初和2000年代，该地区经历了极端的气候条件，包括低积雪和长时间缺乏积雪，对土壤温度和养分动态产生了重要影响。特别是，在阿尔卑斯山的山区带可能是非常敏感的这些现象，在平均雪线预计在全球气候变暖的上升。该研究区位于海拔1450米，在意大利阿尔卑斯山（火星山自然保护区）。在2003/04年冬季，雪被连续删除的治疗阴谋，而参考图保持不受干扰。通过数据记录仪（UTL-1）测量10厘米深度的土壤温度。用埋袋法测定了表层土壤（10 cm深）中氮素的转化情况，积雪的清除导致土壤温度显著降低，同时气温也降低。2004年1月31日，记录到的最低土壤温度分别为落叶松和草甸下的-4.3摄氏度和-4.5摄氏度。当积雪覆盖时，未受干扰的地块的土壤温度保持在冰点以上。除雪引起显着增加净氨化作用在两个土壤和净硝化作用下草甸，但不影响微生物生物量N在这两个地块下降。我们的研究结果表明，较低的温度达到了在没有雪的地块有利于生产无机氮的物理，而不是微生物降解土壤有机质（SOM）。土壤冻结可以增强土壤团聚体的破坏，释放物理保护的有机质和有机质本身的破碎。
The effect of a lack of snow cover in winter was investigated in two soils, beneath larch and meadow, in NW Italy (Vallee d'Aoste Region). During the late 1980s and early 1990s and 2000s, this region experienced extreme climatic conditions including a low snow pack and lack of snow cover for extended periods with important effects on soil temperature and nutrient dynamics. In particular, the mountain belt in the Alps may be extremely sensitive to these phenomena, in relation to the rise in average snowline projected under a warmer global climate.The study area is located at an elevation of 1450 m asl in the Italian Alps (Mont Mars Natural Reserve). During the winter 2003/04, snow was continuously removed in a treatment plot while a reference plot was maintained undisturbed. Soil temperature was measured at 10 cm depth by data loggers (UTL-1). Soil N transformations in the topsoil (10 cm depth) were determined by the buried-bag technique.The removal of the snow cover caused a significant decrease in soil temperature, related to concurrent decreases in air temperature. The lowest soil temperatures recorded were -4.3 degrees C and -4.5 degrees C beneath larch and meadow, respectively, on January 31, 2004. Soil temperature in the undisturbed plots was maintained above the freezing point when the snow cover was present. The snow removal caused significant increases in net ammonification in both soils and net nitrification only under meadow, but did not affect microbial biomass N which decreased in both plots. Our results suggest that the lower temperature reached in the plot without snow favored the production of inorganic N by physical rather than microbial degradation of soil organic matter (SOM). Soil freezing could enhance soil-aggregate disruption releasing physically protected SOM and fragmentation of OM itself.