A. Relevance and sustainability context
A.1 Policy relevance
The growing stock indicator measures the total volume of standing timber in forests and is a key indicator of forest resource availability, carbon storage and long-term forest productivity. It is highly relevant for forest policy, climate policy and national greenhouse gas reporting, as it reflects the capacity of forests to provide biomass, ecosystem services and carbon sequestration over time.
A.2 Sustainability and / or comparative evaluation options
Sustainability perspective: Growing stock can be assessed against historical baselines, sustainable forest management criteria, biodiversity objectives and carbon mitigation pathways. Maintaining adequate growing stock levels is essential for ensuring resilience, ecosystem functioning and long-term wood supply.
Bioeconomy perspective: Growing stock can be related to population size, forest-sector output or the demand for forest biomass. In addition, the share of standing volume suitable for specific value chains (e.g. sawlogs, pulpwood or energy wood) can provide insights into the bioeconomy relevance of forest resources.
B. Data availability
B.1 Stage of development
Established indicator: The indicator is based on long-standing forest inventory systems and is already used in national forest monitoring.
B.2 Data sources
Historical data: National Forest Inventory (Bundeswaldinventur, Thünen Institute).
Future projections: German Projection Report and forest-related scenario studies such as the DIFENs project (Dealing with Impacts on Forests under changing End-use demand, climate change, Natural disturbances and Policy goals). Model-based evaluation of future developments may be required.#
B.3 Coverage over time and replicability
Historical data are available approximately every five years (from NFI (national forest inventory) and CI (carbon inventory) in 2002, 2007, 2012, 2017 and 2022). Future projections may extend to 2050, depending on the scenario framework. The indicator is highly replicable due to the standardized methodology of the National Forest Inventory.
B.4 Coverage across scales and sectors; compatibility
The indicator is available at a national scale for the German forestry sector and can also be disaggregated to the federal-state level. It is compatible with national forest monitoring systems, greenhouse gas reporting and international reporting frameworks.
C. Considerations for operationalization
C.1 Feasibility: Fit for monitoring
Robustness ranking: very robust. Historical estimates are highly reliable and based on established inventory methods. Future projections are subject to uncertainty due to assumptions related to management practices, disturbances and climate change.
C.2 Institutions
Historical data are provided by the Thünen Institute through the National Forest Inventory. Future projections may involve the Thünen Institute, Öko-Institut and other research institutions, depending on the selected modelling approach and scenario framework.
C.3 Future prospects
The continuation of monitoring is considered highly likely. The indicator is already an integral part of forest monitoring, climate reporting and forest resource assessments.
C.4 Costs, considerations and reproducibility
Costs mainly arise from forest inventory implementation, data processing, scenario modelling and the preparation of visualizations. Since the underlying monitoring infrastructure is already established, reproducibility is high.
C.5 Potential for automation
Data processing, indicator calculation and visualization can be partly automated. Nevertheless, expert judgement remains necessary for interpretation, quality assurance and assessment of future developments.
C.6 Presentation options and breakdown / sub-indicator needs
The indicator can be presented as:
- Long-term time series;
- Different volume units (e.g. m³ over bark, m³ under bark);
- Carbon stock or CO₂-equivalent estimates;
- Breakdown by tree species groups (e.g., coniferous and broadleaved trees);
- Breakdown by diameter classes, assortments or management categories where these are available.
C.7 Potential for scenario integration
The indicator has high potential for integration into future forest and bioeconomy scenarios. It is commonly used to evaluate long-term biomass availability, carbon storage and the impacts of alternative forest management strategies.
C.8 Interlinkages and alignment with other monitoring activities
The indicator is closely linked to:
- National greenhouse gas reporting;
- Forest resource assessments;
- Sustainable forest management monitoring;
- Biomass and wood resource monitoring;
- Bioeconomy monitoring related to resource availability and ecosystem services.
Further Comments:
Growing stock should ideally be interpreted together with gross increment, harvest and net stock change indicators. The combined analysis of these indicators provides insights into the balance between forest growth, biomass extraction and carbon storage. For bioeconomy applications, linking growing stock data with utilization statistics and wood assortments can help assess the availability of resources for different value chains while maintaining sustainable forest management objectives.