Diao Yiwei, Wang Anzhi, Jin Changjie, Guan Dexin, Pei Tiefan
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Ying Yong Sheng Tai Xue Bao. 2006 Dec;17(12):2261-5.
Estimating the scalar source/sink distribution of CO2 and its vertical fluxes within and above forest canopy continues to be a critical research problem in biosphere-atmosphere exchange processes and plant ecology. With broad-leaved Korean pine forest in Changbai Mountains as test object, and based on Raupach's localized near field theory, the source/sink and vertical flux distribution of CO2 within and above forest canopy were modeled through an inverse Lagrangian dispersion analysis. This model correctly predicted a strong positive CO2 source strength in the deeper layers of the canopy due to soil-plant respiration, and a strong CO2 sink in the upper layers of the canopy due to the assimilation by sunlit foliage. The foliage in the top layer of canopy changed from a CO2 source in the morning to a CO2 sink in the afternoon, while the soil constituted a strong CO2 source all the day. The simulation results accorded well with the eddy covariance CO2 flux measurements within and above the canopy, and the average precision was 89%. The CO2 exchange predicted by the analysis was averagely 15% higher than that of the eddy correlation, but exhibited identical temporal trend. Atmospheric stability remarkably affected the CO2 exchange between forest canopy and atmosphere.
估算森林冠层内部及上方二氧化碳的标量源/汇分布及其垂直通量,仍然是生物圈 - 大气交换过程和植物生态学中的一个关键研究问题。以长白山阔叶红松林为研究对象,基于劳帕克的局部近场理论,通过反向拉格朗日扩散分析对森林冠层内部及上方二氧化碳的源/汇和垂直通量分布进行了建模。该模型正确预测了由于土壤 - 植物呼吸作用,冠层较深层存在较强的正二氧化碳源强度,以及由于阳光照射的叶片同化作用,冠层上层存在较强的二氧化碳汇。冠层顶层的叶片在上午从二氧化碳源转变为下午的二氧化碳汇,而土壤全天都是较强的二氧化碳源。模拟结果与冠层内部及上方的涡度协方差二氧化碳通量测量结果吻合良好,平均精度为89%。分析预测的二氧化碳交换量平均比涡度相关法高15%,但呈现出相同的时间趋势。大气稳定性显著影响森林冠层与大气之间的二氧化碳交换。