Carbon Budget Assessment and Influencing Factors for Forest Enterprises in the Key State-Owned Forest Area of the Greater Khingan Range, Northeast China

Analyzing the spatial and temporal changes in the carbon budget and its influencing factors is the basis for formulating effective measures to reduce emissions and increase sinks. This study establishes a carbon budget assessment model for forest enterprises, calculating forest carbon stocks and enterprise emissions using volume-derived biomass and emission factor methods. The spatiotemporal evolution characteristics of carbon budgets for forest enterprises in the key state-owned forest area (2017–2021) were analyzed using various methods, including the Mann-Kendall (MK) test and hotspot analysis. Influencing factors are identified through correlation analysis and the optimal parameter geographical detector (OPGD), while their spatial-temporal variations and causal relationships are analyzed using the geographical and temporal weighted regression model (GTWR) and structural equation modeling (SEM). The carbon budget in the Greater Khingan Range state-owned forest area averaged 10.16 × 106 t CO2-eq from 2017 to 2021, showing a gradual upward trend. The average annual carbon budget of forest enterprises was 1.02 × 106 t CO2-eq, which was highest in the central regions and lowest in the periphery. Soil pH, forest area, and elevation are the primary factors. The interaction between paired factors enhances the explanatory power of their impact, and the effects of different influencing factors exhibit both positive and negative variations across forest enterprises. In addition, the middle-aged forest tending area and average annual precipitation positively influenced forest area and soil pH, indirectly enhancing the carbon budget through multifactor interactions. This research can enhance the understanding of the carbon budget in forest enterprises, providing scientific support for the ecological protection of state-owned forests and contributing to the development of sustainable forestry practices that indirectly benefit societal well-being and economic resilience.