本文選題：微生物呼吸 + 微生物碳�。� 參考：《生態(tài)學報》2017年08期

【摘要】：采用室內土柱培養(yǎng)的方法,研究在不同濕度(55%和80%WFPS,土壤充水孔隙度)和不同氮素供給(NH_4Cl和KNO_3,4.5 g N/m~2)條件下,外源碳添加(葡萄糖,6.4 g C/m~2)對溫帶成熟闊葉紅松混交林和次生白樺林土壤融化過程微生物呼吸和微生物碳的激發(fā)效應。結果表明:在整個融化培養(yǎng)期間,次生白樺林土壤對照CO_2累積排放量顯著高于闊葉紅松混交林土壤。隨著土壤濕度的增加,次生白樺林土壤對照CO_2累積排放量和微生物代謝熵(q_(CO_2))顯著降低,而闊葉紅松混交林土壤兩者顯著地增加(P0.05)。兩種林分土壤由葡萄糖(Glu)引起的CO_2累積排放量(9.61—13.49 g C/m~2)顯著大于實驗施加的葡萄糖含碳量(6.4g C/m~2),同時由Glu引起的土壤微生物碳增量為3.65—27.18 g C/m~2,而施加Glu對土壤DOC含量影響較小。因此,這種由施加Glu引起的額外碳釋放可能來源于土壤固有有機碳分解。融化培養(yǎng)結束時,闊葉紅松混交林土壤未施氮處理由Glu引起的CO_2累積排放量在兩種濕度條件下均顯著大于次生白樺林土壤(P0.001);隨著濕度的增加,兩種林分土壤Glu引起的CO_2累積排放量顯著增大(P0.001)。單施KNO_3顯著地增加兩種濕度的次生白樺林土壤Glu引起的CO_2累積排放量(P0.01)。單施KNO_3顯著地增加了兩種濕度次生白樺林土壤Glu引起的微生物碳(P0.001),單施NH_4Cl顯著地增加低濕度闊葉紅松混交林土壤Glu引起的微生物碳(P0.001)。結合前期報道的未凍結實驗結果,發(fā)現凍結過程顯著地影響外源Glu對溫帶森林土壤微生物呼吸和微生物碳的刺激效應(P0.05),并且無論凍結與否,溫帶森林土壤微生物呼吸和微生物碳對外源Glu的響應均與植被類型、土壤濕度、外源氮供給及其形態(tài)存在顯著的相關性。
[Abstract]:Using the method of indoor soil column culture, we studied the conditions of different humidity (55%) and 80% WFPS (soil water-filled porosity) and different nitrogen supply (NH4Cl and KNO34.5g / m ~ (2)). Effects of exogenous carbon supplementation (glucose 6.4g C / m ~ (2)) on microbial respiration and microbial carbon during soil melting in temperate mature broad-leaved Korean pine mixed forest and secondary birch forest. The results showed that the accumulative CO_2 emissions of the secondary birch forest soil were significantly higher than those of the broadleaved Korean pine mixed forest soil during the whole melting period. With the increase of soil moisture, the accumulative CO_2 emission and microbial metabolic entropy of the secondary birch forest decreased significantly, while the soil of broad-leaved Korean pine mixed forest increased P0.05. The cumulative CO_2 emissions from two stand soils caused by Glu) were 9.61-13.49g C / m ~ (2)) significantly higher than that of the experimental application of glucose (6.4g C / m ~ (2)), and the soil microbial carbon increment caused by Glu was 3.65-27.18 g C / m ~ (-2), and that by Glu was 3.65-27.18 g C / m ~ (-2). The effect of DOC content was small. Therefore, this additional carbon release caused by the application of Glu may be derived from the decomposition of organic carbon inherent in the soil. At the end of thawing cultivation, the cumulative CO_2 emission caused by Glu in the soil of mixed broadleaved Korean pine forest was significantly higher than that of P0.001 in the secondary birch forest under two kinds of moisture conditions, and with the increase of soil moisture, the accumulation of CO_2 in the soil of mixed broadleaved Korean pine forest was significantly higher than that in the secondary birch forest. The cumulative CO_2 emission caused by soil Glu in both stands increased significantly (P 0.001). Application of KNO_3 alone significantly increased the cumulative CO_2 emissions caused by Glu in secondary birch forests with two different moisture levels (P0.01). Applying KNO_3 alone significantly increased the microbial carbon (P0.001N) caused by Glu in the soil of two kinds of moisture secondary birch forests, and increased the microbial carbon (P0.001N) caused by Glu in the soil of low-humidity broad-leaved Pinus koraiensis mixed forest by applying NH_4Cl alone. Combined with the reported results of unfrozen experiments, it was found that the freezing process significantly affected the stimulative effects of exogenous Glu on microbial respiration and microbial carbon in temperate forest soil. The responses of microbial respiration and microbial carbon to exogenous Glu in temperate forest soil were significantly correlated with vegetation type, soil moisture, exogenous nitrogen supply and their forms.
【作者單位】： 中國科學院大氣物理研究所大氣邊界層物理和大氣化學國家重點實驗室;中國科學院大學地球科學學院大氣化學與環(huán)境科學系;長安大學地球科學與資源學院;Faculty
【基金】：國家自然科學基金(41175133,21228701,41275166,41321064,41575154)
【分類號】：S714
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本文編號：1800686