基于PnET-CN模型的亚热带人工针叶林生产力与固碳潜力模拟研究

A generalized, lumped-parameter ecological model PnET-CN was calibrated and validated for a subtropical coniferous plantation in southern China. PnET-CN model describes the biogeochemical cycles of carbon (C) and nitrogen (N) and can assist in estimating carbon sequestration potential. For validation of PnET-CN, data from coniferous forest plantations in southern China was used. Simulated daily gross primary productivity (GPP) from 2005 to 2007 agreed well with observations (R2=0.56, S.D.=0.009). Simulations of monthly soil res-piration (Rs) from 2005-2007 agreed well with Rs observations (R2=0.67, S.D. =0.03). Simu-lated annual net primary productivity (NPP) from 1998-2006 was 803 33 gCm 2a 1, about 4% higher than NPP observation (752 51 gCm 2a 1). Simulations of annual NEP from 2005 2007 only overestimate 9 gCm 2a 1 (4%), 4 gCm 2a 1 (1%) and 34 gCm 2a 1 (8%) compared to NEP observations, respectively. Simulated annual foliar N concentration (FolNCon) (1.09%) is 10% lower than observed monthly FolNCon (0.87%-1.58%). Simulated annual N leaching (0.26 gNm 2) is about 10% lower than leaching observation (0.29 gNm 2). PnET-CN model valida-tion indicates that PnET-CN is capable to simulate daily GPP, annual NPP, annual NEP, monthly Rs, annual FolNCon and annual nitrate N leaching for subtropical coniferous planta-tions in southern China. The results obtained from the validation test revealed that PnET-CN model can be used to simulate carbon sequestration of planted coniferous forests in southern China to a high level of precision. Sensitivity analysis suggests that great care should be taken in developing generalizations as to how forests will respond to a changing climate. PnET-CN performed satisfactorily in comparison to other models that have already been calibrated and validated in coniferous planted subtropical forests in China. Based on PnET-CN validation and its comparison to other models, future improvement of PnET-CN should focus on seasonal foliar N dynamics and the effects of water stress on autotrophic respirations in subtropical coniferous plantations in southern China.

Assessing productivity and carbon sequestration capacity of subtropical coniferous plantations using the process model PnET-CN

A generalized, lumped-parameter ecological model PnET-CN was calibrated and validated for a subtropical coniferous plantation in southern China. PnET-CN model describes the biogeochemical cycles of carbon (C) and nitrogen (N) and can assist in estimating carbon sequestration potential. For validation of PnET-CN, data from coniferous forest plantations in southern China was used. Simulated daily gross primary productivity (GPP) from 2005 to 2007 agreed well with observations (R2=0.56, S.D.=0.009). Simulation...