The global carbon dioxide flux in soil respiration and its relationship to vegetation and climate
The global carbon dioxide flux in soil respiration and its relationship to vegetation and climate
复制标题
DOI：
10.3402/tellusb.v44i2.15428
复制
发表时间：
1992-04
期刊：
影响因子：
--
通讯作者：
J. Raich;W. Schlesinger
中科院分区：
文献类型：
--
作者：
J. Raich;W. Schlesinger
我们回顾了陆地和湿地生态系统测量的土壤呼吸速率，以定义每年全球土壤CO 2 通量，识别全球通量估计中的不确定性，并研究温度、降水和植被对土壤呼吸速率的影响。根据生物群落陆地面积的推断，全球每年来自土壤的 CO 2 通量估计平均为 (± S.D.) 68 ± 4 PgC/年。干旱、半干旱和热带地区土壤呼吸的测量相对较少；这些区域应成为进一步研究的重点。在全球范围内，土壤呼吸速率与年平均气温和年平均降水量呈正相关。不同植被生物群落的年平均净初级生产力（NPP）与其年平均土壤呼吸速率之间存在密切相关，土壤呼吸平均比年平均NPP高24%。该差异代表了根呼吸对土壤总CO 2 流出量的贡献的最小估计。土壤碳周转率的估计范围从苔原和泥炭湿地的 500 年到热带稀树草原的 10 年不等。我们还评估人类活动对土壤呼吸速率的潜在影响，特别关注土地利用变化、土壤施肥、灌溉和排水以及气候变化。人类活动对土壤呼吸速率的影响鲜有记录，而且因地点而异。特别重要的是温度和降水的潜在变化。根据对现场测量的审查，土壤总呼吸的 Q 10 值的中值为 2.4。全球变暖导致的土壤呼吸增加可能对温室效应产生积极的反馈。 DOI：10.1034/j.1600-0889.1992.t01-1-00001.x
We review measured rates of soil respiration from terrestrial and wetland ecosystems to define the annual global CO 2 flux from soils, to identify uncertainties in the global flux estimate, and to investigate the influences of temperature, precipitation, and vegetation on soil respiration rates. The annual global CO 2 flux from soils is estimated to average (± S.D.) 68 ± 4 PgC/ yr, based on extrapolations from biome land areas. Relatively few measurements of soil respiration exist from arid, semi-arid, and tropical regions; these regions should be priorities for additional research. On a global scale, soil respiration rates are positively correlated with mean annual air temperatures and mean annual precipitation. There is a close correlation between mean annual net primary productivity (NPP) of different vegetation biomes and their mean annual soil respiration rates, with soil respiration averaging 24% higher than mean annual NPP. This difference represents a minimum estimate of the contribution of root respiration to the total soil CO 2 efflux. Estimates of soil C turnover rates range from 500 years in tundra and peaty wetlands to 10 years in tropical savannas. We also evaluate the potential impacts of human activities on soil respiration rates, with particular focus on land use changes, soil fertilization, irrigation and drainage, and climate changes. The impacts of human activities on soil respiration rates are poorly documented, and vary among sites. Of particular importance are potential changes in temperatures and precipitation. Based on a review of in situ measurements, the Q 10 value for total soil respiration has a median value of 2.4. Increased soil respiration with global warming is likely to provide a positive feedback to the greenhouse effect. DOI: 10.1034/j.1600-0889.1992.t01-1-00001.x