Predicted increase in climate warming will affect soil organic carbon (SOC) dynamics in vulnerable cold alpine environments. In contrast to freeze and thaw cycles, less is known about the effects of temperature regimes in the range between 2 and 10 °C on SOC availability to soil microorganisms. For this reason, CO₂ efflux, extracellular enzyme activities and microbial communities were measured in an incubation experiment with three temperature treatments: (T1) continuous 10 °C, (T2) cooled down to 2 °C, and (T3) rewarmed from 2 to 10 °C. Two forest soils at low elevation and two grassland soils at high elevation were taken from two sites with distinct bedrock types (limestone at Hochschwab, gneiss and schist at Rauris). The CO₂ efflux did not differ significantly between the elevation levels at the two sites. In the continuous warm treatment T1, the relative decline in CO₂ efflux was stronger in the two Rauris than in the two Hochschwab soils during the 0–123 days period. In the cooling treatment T2, the cumulative ΣCO₂C efflux of the Hochschwab soils was lowered by 32% and that of the Rauris soils by only 19% compared with T1 during the 30–123 days period. In the rewarming treatment T3, the ΣCO₂ efflux was on average 33% higher than that of treatment T1 during the 91–123 days period, ranging from +8% to +62%. Phospholipid fatty acid (PLFA) composition and extracellular enzyme activities were not markedly affected by incubation time or temperature treatments. The differences in bedrock properties had stronger effects on the ΣCO₂ efflux, enzyme activities as well as total PLFA content and composition than elevation level or vegetation. Other, largely unknown factors control the rewarming effects on the mobilisation of a labile SOC pool.

在脆弱的寒冷高山环境中，气候变暖的预计增加将影响土壤有机碳（SOC）的动态。与冷冻和解冻循环相反，人们对2至10°C的温度范围对土壤微生物SOC利用率的影响知之甚少。因此，在三个温度处理的孵育实验中测量了CO _2的流出，细胞外酶活性和微生物群落：（T1）连续10°C，（T2）冷却至2°C，以及（T3）从2至10°C。从两个具有不同基岩类型的地点（Hochschwab的石灰岩，片麻岩和Rauris的片岩）采集了两个低海拔的森林土壤和两个高海拔的草地土壤。一氧化碳₂在两个地点的海拔高度之间，流出没有显着差异。在连续温热处理T1中，在0-123天期间，两个Rauris地区的CO ₂外流相对下降要强于两个Hochschwab土壤。在冷却处理T2，累计ΣCO ₂的Hochschwab土壤Ç流出在30-123天期间降低了32％，而且劳瑞斯土壤通过只有19％与T1进行比较。在复温处理T3中，ΣCO ₂在91-123天内，外排比T1处理平均高出33％，范围从+ 8％到+ 62％。磷脂脂肪酸（PLFA）的组成和细胞外酶活性不受孵育时间或温度处理的明显影响。在基岩性质的差异对的影响ΣCO更强₂流出，酶活性以及总磷脂脂肪酸含量和组成比高度水平或植被。其他几乎未知的因素控制着不稳定的SOC库动员的再热效应。