Sustained Biomass Carbon Sequestration by China’s Forests from 2010 to 2050

Abstract

China’s forests have functioned as important carbon sinks. They are expected to have substantial future potential for biomass carbon sequestration (BCS) resulting from afforestation and reforestation. However, previous estimates of forest BCS have included large uncertainties due to the limitations of sample size, multiple data sources, and inconsistent methodologies. This study refined the BCS estimation of China’s forests from 2010 to 2050 using the national forest inventory data (FID) of 2009−2013, as well as the relationships between forest biomass and stand age retrieved from field observations for major forest types in different regions of China. The results showed that biomass–age relationships were well-fitted using field data, with respective R2 values more than 0.70 (p < 0.01) for most forest types, indicating the applicability of these relationships developed for BCS estimation in China. National BCS would increase from 130.90 to 159.94 Tg C year−1 during the period of 2010−2050 because of increases in forest area and biomass carbon density, with a maximum of 230.15 Tg C year−1 around 2030. BCS for young and middle-aged forests would increase by 65.35 and 15.38 Tg C year−1, respectively. 187.8% of this increase would be offset by premature, mature, and overmature forests. During the study period, forest BCS would increase in all but the northern region. The largest contributor to the increment would be the southern region (52.5%), followed by the southwest, northeast, northwest, and east regions. Their BCS would be primarily driven by the area expansion and forest growth of young and middle-aged forests as a result of afforestation and reforestation. In the northern region, BCS reduction would occur mainly in the Inner Mongolia province (6.38 Tg C year−1) and be caused predominantly by a slowdown in the increases of forest area and biomass carbon density for different age–class forests. Our findings are in broader agreement with other studies, which provide valuable references for the validation and parameterization of carbon models and climate-change mitigation policies in China.

Current and Future Potential of Shellfish and Algae Mariculture Carbon Sinks in China

“…It is assumed that the growth rate of shellfish and algae mariculture production in China will be stable over the next few decades, and as such, the shellfish and algae carbon sink in China will grow to 1,751,700 tons/year in 2030, representing a 27.02% increase over 2019. Over that same period, the forest area of China will reach 196.21 × 10 6 hectares, with a carbon sink capacity of 230.15 million tons/year [ 39 ], so it can be calculated that the carbon sink from harvesting shellfish and algae in 2030 will be equivalent to the carbon fixed by 0.15 × 10 6 hectares of forest. The carbon sink capacity of wetlands in China is 315.76 tons per hectare [ 40 ], which means that the carbon sink achieved by harvesting shellfish and algae in 2030 will be equivalent to the carbon fixed by 5546.93 hectares of wetlands.…”

Modelling Tree Growth in Monospecific Forests from Forest Inventory Data

“…We fitted the ODE (regardless of fitting to individuals or quantile plots) by using the ODE function from the deSolve package and the modCost and modFit functions from the FME package [48]. Note that we have not fitted the explicit solution of the differential equation (as, for instance, in Zhang et al [28]), so this approach was suitable for ODEs with no explicit solution.…”

“…Systematic data, such as the national forest inventories, provide an excellent opportunity for public administrations and stakeholders to better monitor and predict biomass and above-ground carbon stocks in existing forests. Tree growth dynamics can be used along with volumetric formulae or allometric relations to predict timber yield (as in [52]) or carbon storage [28]. Additionally, other ODE models can be fitted to obtain tree height dynamics and to complete forest dynamics information.…”

“…However, it is key to determine how many temporal censuses are required in order to obtain an adequate parameterization. Although the explicit solution of this equation has been used for this purpose both worldwide [28] and in Spanish forests [29], alone or within the so-called generalized algebraic difference approach [30], we showed that, using the BCR ordinary differential equation, three censuses are an adequate approximation for modelling short-term forest stocks' dynamics. This allowed us to exploit large-scale National Forest Inventory (NFI) data for prospective mitigation analyses.…”

Valuing Carbon Sequestration to Finance Afforestation Projects in China

“…It has undertaken large reforestation programs in most provinces, in particular since 1999. According to Delang and Yuan (2016) and Zhang et al (2018), afforestation in China is generally based on three tree types: Ecological trees, economic trees, and bamboo [21,22]. This distinction is based on the fact that (i) the tree products are different (ecological trees and bamboo mainly produce timber, whereas economic trees mainly produce non-timber products, such as fruits, and (ii) significant differences exist concerning growth patterns and forest management.…”