In forest management, the sustainability of a multitude of economic, ecological and socio-economic impacts and services is assessed. The role of forests in the global carbon (C) cycle is almost exclusively assessed through an ecosystem approach that relates emissions from timber harvesting and removals through biomass growth and C sequestration. While harvested wood leads to a reduction in the C-stock in forest C-pools, the use of wood for energy and production of wood-based materials results in significant emission reductions by substituting in place of greenhouse gas (GHG) intensive fuels and energy-intensive non-wood materials respectively.

We present a new indicator approach for the assessment of sustainable forest management that includes the entire emissions and removals associated with the harvested wood along the wood product value chain and thus represents represents C-sustainability with respect to emissions and removals. The indicator is implemented in two variants. If information available on wood use and the carbon offsets associated with it is sufficient, the indicator can be derived by presenting emissions from wood harvesting and removals from wood use in the form of a carbon balance (C-balance indicator). If the balance is even or if removals predominate, forest management fulfills the requirement of C-sustainability. If the information is insufficient, the emissions from the wood harvest and possible wood processing losses are summed up, and the necessary displacement factor (DF) is calculated, which is necessary to compensate the corresponding emissions by carbon offsets of the wood use (DF-indicator). A comparison of the necessary displacement factor with common carbon offsets of typical wood uses allows an assessment of C-sustainability.

The effectiveness of the C-indicator for assessing sustainable forest management is illustrated by two case studies. We found that in order to achieve carbon neutrality, substitution factors between 1.9 (lignite) and 2.5 (gas) are necessary, depending on the fossil fuel substituted. If no energetic substitution is assumed, the DF increases to a value of 3.3. In situations with high harvest losses, the necessary DFs well exceed values that can be achieved even under very positive assumptions; C-sustainability is therefore not met. Both approaches allow an assessment of C-sustainability beyond forest boundaries by giving appropriate weight to the importance of wood use in the carbon cycle. In addition to the implication of the indicator to evaluate SFM, we claim that this indicator is responsive to the emerging global forest related international processes and their reporting requirements such as Reducing Emissions from Deforestation and forest Degradation in Developing Countries (REDD+) as well as nationally appropriate mitigation actions (NDCs, Low Emission Development Strategy).

在森林管理中，评估了多种经济，生态和社会经济影响及服务的可持续性。森林在全球碳（C）循环中的作用几乎完全通过生态系统方法进行评估，该方法将木材采伐和生物量增长和碳固存的清除相关联。虽然采伐的木材导致森林C池中的C储量减少，但将木材用作能源和生产木质材料可通过代替温室气体（GHG）密集型燃料和能源来显着减少排放-高强度非木材材料。

我们提出了一种用于评估可持续森林管理的新指标方法，该方法包括沿木材产品价值链与采伐木材相关的全部排放量和清除量，因此代表了排放量和清除量的C可持续性。该指标有两种变体。如果有关木材使用和与之相关的碳补偿的可用信息足够，则可以通过以碳平衡的形式显示木材采伐和木材使用的清除量（C平衡指标）来得出指标。如果平衡是平衡的或砍伐占主导地位，则森林经营将满足C可持续性的要求。如果信息不足，则将木材采伐产生的排放量和可能的木材加工损失相加，然后计算必要的位移因数（DF），这对于通过木材用途的碳补偿补偿相应的排放量（DF指示器）是必要的。将必要的置换因子与典型木材用途的常见碳补偿进行比较，可以评估碳的可持续性。

通过两个案例研究说明了C指标评估可持续森林管理的有效性。我们发现，为了实现碳中和，根据所替代的化石燃料，替代因子必须介于1.9（褐煤）和2.5（气体）之间。如果未假定能量替代，则DF会增加到3.3。在高收成的情况下，即使在非常积极的假设下，必要的DF也远远超过了可以达到的值；因此无法满足C的可持续性。两种方法都可以通过适当重视木材在碳循环中的重要性来评估森林边界以外的碳可持续性。除了暗示评估SFM的指标外，