Implication of community-level ecophysiological parameterization to modelling ecosystem productivity:a case study across nine contrasting forest sites in eastern China

Parameterization is a critical step in modelling ecosystem dynamics.However,assigning parameter values can be a technical challenge for structurally complex natural plant communities;uncertainties in model simulations often arise from inappropriate model parameterization.Here we compared five methods for defining community-level specific leaf area(SLA)and leaf C:N across nine contrasting forest sites along the North-South Transect of Eastern China,including biomass-weighted average for the entire plant community(AP_BW)and four simplified selective sampling(biomass-weighted average over five dominant tree species[5DT_BW],basal area weighted average over five dominant tree species[5DT_AW],biomass-weighted average over all tree species[AT_BW]and basal area weighted average over all tree species[AT_AW]).We found that the default values for SLA and leaf C:N embedded in the Biome-BGC v4.2 were higher than the five computational methods produced across the nine sites,with deviations ranging from 28.0 to 73.3%.In addition,there were only slight deviations(<10%)between the whole plant community sampling(AP_BW)predicted NPP and the four simplified selective sampling methods,and no significant difference between the predictions of AT_BW and AP_BW except the Shennongjia site.The findings in this study highlights the critical importance of computational strategies for community-level parameterization in ecosystem process modelling,and will support the choice of parameterization methods.

Carbon sequestration of Chinese forests from 2010 to 2060:spatiotemporal dynamics and its regulatory strategies

Forestation is important for sequestering atmospheric carbon,and it is a cost-effective and nature-based solution(NBS)for mitigating global climate change.Here,under the assumption of forestation in the potential plantable lands,we used the forest carbon sequestration(FCS)model and field survey involving 3365 forest plots to assess the carbon sequestration rate(CSR)of Chinese existing and new forestation forests from 2010 to 2060 under three forestation and three climate scenarios.Without considering the influence of extreme events and human disturbance,the estimated average CSR in Chinese forests was 0.358±0.016 Pg C a^(-1),with partitioning to biomass(0.211±0.016 Pg C a^(-1))and soil(0.147±0.005 Pg C a^(-1)),respectively.The existing forests account for approximately 93.5%of the CSR,which will peak near 2035,and decreasing trend was present overall after 2035.After 2035,effective tending management is required to maintain the high CSR level,such as selective cutting,thinning,and approximate disturbance.However,new forestation from 2015 in the potential plantable lands would play a minimal role in additional CSR increases.In China,the CSR is generally higher in the Northeast,Southwest,and Central-South,and lower in the Northwest.Considering the potential losses through deforestation and logging,it is realistically estimated that CSR in Chinese forests would remain in the range of 0.161–0.358 Pg C a^(-1) from 2010 to 2060.Overall,forests have the potential to offset 14.1%of the national anthropogenic carbon emissions in China over the period of 2010–2060,significantly contributing to the carbon neutrality target of 2060 with the implementation of effective management strategies for existing forests and expansion of forestation.