Assessment on forest carbon sequestration in the Three-North Shelterbelt Program region, China

Forest ecosystems are a major component of the terrestrial ecosystems as they provide a variety of important ecosystem services, especially climate regulation via carbon sequestration. The Three-North Shelterbelt Program (TNSP), a pioneer for China's large-scale ecological construction, has promoted massive afforestation and forest dynamics since 1978. Quantitative analysis of carbon sequestration and its economic value of sub-type forest landscapes in the TNSP region is crucial for better understanding the capacity of forest carbon sequestration and providing reasonable forest management. Therefore, we assess the forest carbon sequestration in the TNSP region using the InVEST model based on spatial datasets during 1990–2015. Our results showed that forests in the TNSP region had strong carbon sequestration capacity. Total carbon sequestration fluctuated and overall showed a decreasing trend, with a reduction rate of 1.92% during the period of 1990–2015. The carbon sequestration of each carbon pool (namely aboveground biomass, belowground biomass, soil, and dead organic matter) also decreased slightly and the changes mainly happened in the north of northeastern China and along the southeast of central north China. Additionally, in monetary terms, the economic value of carbon sequestration reflected that the TNSP was worth implementing, with a small amount of investment in exchange for large carbon sequestration benefits. This work provides an up-to-date attempt to calculate carbon sequestration of forest more accurately, quantify economic values of carbon sequestration for forest ecosystems, which will give a baseline reference for related studies in the TNSP region, as well as other similar reforestation area.