Organic matter dynamics in a temperate forest as influenced by soil frost
Organic matter dynamics in a temperate forest as influenced by soil frost
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DOI：
10.1002/jpln.201100009
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发表时间：
2011-10
影响因子：
2.5
通讯作者：
A. Schmitt;B. Glaser
中科院分区：
文献类型：
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作者：
A. Schmitt;B. Glaser
未来，气候模型预测全球地表温度将上升，冬季降水量将从降雪量减少变为降雨量增加。如果没有保护性的积雪，冻结可能会更加强烈，并可能进入土壤更深处，影响碳循环和土壤有机质（SOM）动态。我们移走了菲希特尔山山脉挪威云杉林的天然积雪。从2005年12月下旬到2006年2月中旬，在三个重复的地块上进行冬季试验。因此，从2006年1月到4月，我们在15厘米深（地表以下5厘米深，温度高达-5 ° C）的地方引发了土壤霜冻，而积雪覆盖的对照地块从未达到低于0°C的温度。SOM的数量和质量其次是总有机碳和生物标志物分析。虽然土壤霜冻没有影响总有机碳和木质素浓度，香草单体（Ac/Ad）V和微生物糖浓度的分解下降，在霜冻期结束时，这些结果证实减少SOM矿化霜下。土壤微生物生物量不受霜冻事件的影响，或比实验后直接积累的微生物残留物（如微生物糖）更快地恢复。然而，在随后的秋季，土壤微生物生物量显着高于除雪（SR）处理相比，尽管较低的CO2呼吸。水分胁迫指标PLFA [cy 17：0 + cy 19：0] / [16：1ω 7 c + 18：1ω 7 c]增加。这些结果表明，土壤微生物呼吸，因此，活性是不密切相关的土壤微生物生物量，但更强烈地控制基质的可用性和质量。PLFA图谱表明，真菌比细菌更容易受到土壤霜冻的影响。
In the future, climate models predict an increase in global surface temperature and during winter a changing of precipitation from less snowfall to more raining. Without protective snow cover, freezing can be more intensive and can enter noticeably deeper into the soil with effects on C cycling and soil organic matter (SOM) dynamics. We removed the natural snow cover in a Norway spruce forest in the Fichtelgebirge Mts. during winter from late December 2005 until middle of February 2006 on three replicate plots. Hence, we induced soil frost to 15 cm depth (at a depth of 5 cm below surface up to –5°C) from January to April 2006, while the snow-covered control plots never reached temperatures < 0°C. Quantity and quality of SOM was followed by total organic C and biomarker analysis. While soil frost did not influence total organic-C and lignin concentrations, the decomposition of vanillyl monomers (Ac/Ad)V and the microbial-sugar concentrations decreased at the end of the frost period, these results confirm reduced SOM mineralization under frost. Soil microbial biomass was not affected by the frost event or recovered more quickly than the accumulation of microbial residues such as microbial sugars directly after the experiment. However, in the subsequent autumn, soil microbial biomass was significantly higher at the snow-removal (SR) treatments compared to the control despite lower CO2 respiration. In addition, the water-stress indicator (PLFA [cy17:0 + cy19:0] / [16:1ω7c + 18:1ω7c]) increased. These results suggest that soil microbial respiration and therefore the activity was not closely related to soil microbial biomass but more strongly controlled by substrate availability and quality. The PLFA pattern indicates that fungi are more susceptible to soil frost than bacteria.