摘要
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)。
Aims The objective was to investigate the respiration rate of snowpack soil in relation to temperature in the alpine tundra community ofSanguisorba sitchensis （= S. stipulata） in the Changbai Mountain, northeastern China. Methods Soil respiration under different temperatures was measured with an LI-8100 automated CO2 flux system in the laboratory, and annual respiration was estimated based on current and presumed temperature scenarios. Important findings Soil temperature under snowpack most of the year was around or over 0 ℃, and the variation was less than 20 ℃. Estimated respiration rates within 10 cm depth were 307.1 g C·m^-2·a^-1 at 2 036 m elevation and 270.9 g C·m^-2·a^-1 at 2 260 m. Because the snow cover was present for a long period, the length of which increased with elevation, winter respiration accounted for 42.5% at 2 036 m and 49.7% at 2 260 m. Under the scenario that the snow period decreases if annual temperature rises 1 ℃, annual respiration would increase by 8% or 0.25 g C·kg^-1·a^-1 （22.65 g C·m^-2·a^-1）, but winter respiration would decrease by 0.118 g C·kg^-1·a^-1 （10.81 g C·m^-2·a^-1）.
出处
《植物生态学报》
CAS
CSCD
北大核心
2010年第5期477-487,共11页
Chinese Journal of Plant Ecology
基金
国家自然科学基金(40671098)资助项目
关键词
高山苔原
大白花地榆
雪斑
土壤温度
土壤呼吸
alpine tundra, Sanguisorba sitchensis （=S. stipulata）, snowpack, soil temperature, soil respiration
