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利用LI-8100土壤呼吸测定系统,在室内控制温度条件下测定了长白山高山苔原季节性雪斑大白花地榆(Sanguisorba sitchensis(=S.stipulata))群落土壤呼吸对温度的响应过程,并根据野外连续测定的全年温度,估算了雪斑群落土壤呼吸的季节变化,同时模拟气温升高对土壤呼吸的影响。雪斑土壤温度全年大部分时间维持在0℃以上,极端温度变动幅度不超过20℃。模拟计算了10cm深土壤的呼吸强度,海拔2036m处为307.1gC·m–2·a–1,海拔2260m处的呼吸量为270.9gC·m–2·a–1。由于积雪时间长,冬季呼吸占很大比例,而且随着海拔的升高比例加大。从海拔2036m到2260m,积雪期土壤呼吸分别占全年的42.5%(125.4gC·m–2·a–1)和49.7%(128.7gC·m–2·a–1)。模拟气温升高1℃并假设积雪时间减少20天,冬天的呼吸量减少8%左右,但全年总呼吸量增加8%左右。升温后,平均增加的呼吸量为0.25gC·kg–1·a–1(或22.65gC·m–2·a–1),冬季呼吸量减少0.118gC·kg–1·season–1(或10.81gC·m–2·season–1)。
Using LI-8100 soil respiration measuring system, the soil respiration response to temperature was measured under the indoor control temperature in the Sanguisorba sitchensis (= S.stipulata) community in the Changbai Mountain alpine tundra, The seasonal variation of soil respiration of snow patches was estimated and the effects of elevated temperature on soil respiration were also evaluated. Snowy soil temperature is maintained above 0 ℃ most of the year, the extreme temperature fluctuations of not more than 20 ℃. The respiration intensity of 10 cm deep soil was simulated and calculated, with an air volume of 307.1 gC · m-2 · a-1 at 2036 m and an air volume of 270.9 gC · m-2 · a-1 at an altitude of 2260 m. Due to the long time of snow cover, winter respiration accounted for a large proportion, and the proportion increased with the elevation. Soil respiration during the snow cover period accounted for 42.5% (125.4gC · m -2 · a -1) and 49.7% (128.7gC · m -2 · a -1), respectively, from 2036m to 2260m above sea level. Simulated air temperature increased by 1 ℃ and assumed that the snow time decreased by 20 days, winter respiration reduced by about 8%, but the annual total respiration increased by about 8%. After warming, the average increase of respiration was 0.25gC · kg-1 · a-1 (or 22.65gC · m-2 · a-1) and the decrease of winter respiration was 0.118gC · kg-1 · season- gC · m-2 · season-1).