Carbon Storage and Density of Forest Ecosystems in Heilongjiang Province, China

Accurately estimating carbon storage for forest ecosystems is important for understanding the role of forests in global warming and also in supporting decision-making processes in forest management. Using forest inventory data in combination with field data, we explored characteristics of carbon storage, density, and distribution for different forest ecosystems and their components in Heilongjiang Province, Northeast China. Results showed that total carbon storage was 4125.002 Tg C. The soil layer accounted for the most storage with 3205.764 Tg C or 77.7% of the total. This was followed by the canopy, litter, and shrub-grass layers with 800.965 (19.4%), 106.568 (2.6%), and 11.705 Tg C (0.3%), respectively. The average carbon density of forest ecosystems was 215.816 Mg C ha^(-1), with the soil layer (167.722 Mg C ha^(-1)) the densest, followed by the canopy layer (41.906 Mg C ha^(-1)), litter (5.576 Mg C ha^(-1)), and shrub layers (0.612 Mg C ha^(-1)). Carbon storage in different forest ecosystems varied 37.87~1306.63 Tg C, while C density ranged 167.68~256.87 Mg C ha^(-1), with the highest and lowest values observed in the soil and shrub-grass layers, respectively. That implies that the soil is the main body for forest carbon storage. The methods and data used for forest carbon storage estimation obviously affected results of the estimates. Rational methods should be adopted based on obtaining sufficient data for estimates. Middle-aged forests accounted for a greater proportion of forests in the province than forests in other age classes, and proper management of forests could increase the carbon sequestration of forest ecosystems.