Researchers from Voronezh reviewed the planned timeframes for carbon absorption / emissions reduction in the Paris climate agreement, which has separate credits for projects lasting 5, 10 and 15 years with some extensions. A common method is to use reforestation together with forestry management to help absorb carbon. They noted that most Reducing Emissions from Deforestation and forest Degradation (REDD+) projects are being implemented in public forest, especially high carbon forests. Some of the issues regarding reforestation including monoculture planting, carbon offsetting compared with other types of emission reduction, land use changes for reforestation projects with higher costs and lower returns.

To understand how that might apply to Russia, they used predictive assessment:

Calculations were carried out on the basis of the methodology developed at the Center for Forest Ecology and Productivity of Russian Academy of Sciences (CEPF RAS) for the informational and analytical assessment of the carbon budget of afforestation/reforestation at the local level [18].
Carbon absorption and stock were assessed for pool of live phytomass.
Pools of dead wood, litter, and soil were not conservatively taken into account in
the calculations

Morkovina et al, 2023, http://dx.doi.org/10.3390/f14081611

To assess the investment costs, they reviewed reforestation design, project validation and verification, forest labour costs, equipment purchase/hire and maintenance, soil preparation, seedling growth costs, fuel and energy costs. They used these across 15, 30 and 45 year timeframes. 2023 costs for the forest Steppe were approximately $1130 ± 12% depending on cultivation techniques and location.

They found that investment for projects over 20 years are likely to show the best return including planting native fast-growing species, taking 10-30 years for maximum carbon sequestration. Their findings were similar to other research with younger trees, showing less CO₂ absorption during their first ten years. They additionally recommend use of rotation to manage tree lifecyles.

Morkovina S, Sheshnitsan S, Panyavina E, Ivanova A and Kuznetsov D 2023 Opportunities and Prospects for the Implementation of Reforestation Climate Projects in the Forest Steppe: An Economic Assessment Forests 14 1611 Online: http://dx.doi.org/10.3390/f14081611