Dependence of soil respiration on soil temperature and soil moisture in successional forests in southern China |
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出 版 社:Journal of Integrative Plant Biology |
发表时间:2006 |
台 站:
鼎湖山森林生态系统定位研究站
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作 者:Tang Xuli,Zhou Guoyi,Liu Shuguang,Zhang Deqiang,Zhou Cunyu |
点 击 率:397257 |
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关 键 字(英文):Dinghushan Nature Reserve; moisture sensitivity; Q10; soil CO2 efflux; soil respiration; subtropical forests; successional forests; temperature sensitivity; Tropic of Cancer. |
摘 要(英文):The spatial and temporal variations in soil respiration and its relationship with biophysical factors in forests near the Tropic of Cancer remain highly uncertain. To contribute towards an improvement of actual estimates, soil respiration rates, soil temperature, and soil moisture were measured in three successional subtropical forests at the Dinghushan Nature Reserve (DNR) in southern China from March 2003 to February 2005. The overall objective of the present study was to analyze the temporal variations of soil
respiration and its biophysical dependence in these forests. The relationships between biophysical factors and soil respiration rates were compared in successional forests to test the hypothesis that these forests responded similarly to biophysical factors. The seasonality of soil respiration coincided with the seasonal climate pattern, with high respiration rates in the hot humid season (April-September) and with low rates in the cool dry season (October-March). Soil respiration measured at these forests showed a clear increasing trend with the progressive succession. Annual mean (±SD) soil respiration rate in the DNR forests was (9.0 ± 4.6) Mg CO2-C/hm2 per year, ranging from (6.1 ± 3.2) Mg CO2-C/hm2 per year in early successional forests to (10.7 ± 4.9) Mg CO2-C/hm2 per year in advanced successional forests. Soil respiration was correlated with both soil temperature and moisture. The T/M model, where the two biophysical variables are driving factors, accounted for 74%–82% of soil respiration variation in DNR forests. Temperature sensitivity decreased along progressive succession stages, suggesting that advanced-successional forests have a good ability to adjust to temperature. In contrast, moisture increased with progressive
succession processes. This increase is caused, in part, by abundant respirators in advanced-successional forest, where more soil moisture is needed to maintain their activities. |
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Dependence of Soil Respiration on Soil Temperature and Soil Moisture in Successional Forests in Southern China.pdf |