The Effect of Harvesting on National Forest Carbon Sinks up to 2050 Simulated by the CBM-CFS3 Model: A Case Study from Slovenia

Abstract

With the advent of global warming, forests are becoming an increasingly important carbon sink that can mitigate the negative effects of climate change. An understanding of the carbon dynamics of forests is, therefore, crucial to implement appropriate forest management strategies and to meet the expectations of the Paris Agreement with respect to international reporting schemes. One of the most frequently used models for simulating the dynamics of carbon stocks in forests is the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3). We applied this model in our study to evaluate the effects of harvesting on the carbon sink dynamics in Slovenian forests. Five harvesting scenarios were defined: (1) business as usual (BAU), (2) harvesting in line with current forest management plans (PLAN), (3) more frequent natural hazards (HAZ), (4) high harvest (HH) and (5) low harvest (LH). The simulated forest carbon dynamics revealed important differences between the harvesting scenarios. Relative to the base year of 2014, by 2050 the carbon stock in above-ground biomass is projected to increase by 28.4% (LH), 19% (BAU), 10% (PLAN), 6.5% (HAZ) and 1.2% (HH). Slovenian forests can be expected to be a carbon sink until harvesting exceeds approximately 9 million m3 annually, which is close to the calculated total annual volume increase. Our results are also important in terms of Forest Reference Levels (FRL), which will take place in European Union (EU) member states in the period 2021–2025. For Slovenia, the FRL was set to −3270.2 Gg CO2 eq/year, meaning that the total timber harvested should not exceed 6 million m3 annually.

Are Slovenia’s forests deviating from sustainable development?

“…There is a larger potential for storing carbon in optimal developmental phase stocking (higher SDIs) and a more balanced felling-increment ratio. Notably, recent simulations suggest that optimal carbon storage can only be achieved through sustainable felling (Thürig and Kaufmann, 2008;Jevšenak et al, 2020). Similarly, our simulation with balanced growing stocks shows that if the developmental phases of Slovenian forests had growing stocks as high as the forests of Burgenland or Switzerland, the Slovenian balanced growing stock would amount to 347 m 3 /ha and 322 m 3 /ha, respectively.…”

Between Biodiversity Conservation and the Supply for Broadleaved Wood: A Case Study of State Forests National Forest Holding (Poland)

“…Our findings are also relevant for forest management and conservation practice, as they show that environmentally sound management over long periods of time is essential for sustainability. Our study and the studies of other authors illustrate that it is possible to create empirical models that predict harvest with high discriminating power at the national or regional level based on forest attributes [53][54][55][56][57]. Our results highlight the need to protect remaining old-growth forests, which are diminishing, and the need to balance conservation and management objectives in the future to ensure sustainable forests in Eastern Europe [58].…”

Closing an open balance: The impact of increased tree harvest on forest carbon

“…In addition, papers that were known in advance by the authors to include relevant data were collected. In total, 33 papers were added (Blattert et al, 2020; Böttcher et al, 2008, 2018; Chen et al, 2018; Gustavsson et al, 2021; Gutsch et al., 2018; Härtl et al, 2017; Heinonen et al, 2017; Helin et al, 2016; Holtsmark, 2012; Hynynen et al, 2015; Jandl, Ledermann, et al, 2018; Jevšenak et al, 2020; Knauf et al, 2015; Krause et al., 2020; Leskinen et al, 2020; Mund et al, 2015; Oehmichen et al, 2018; Olguin et al, 2018; Pang et al, 2017; Pilli et al, 2017; Pingoud et al, 2016; Pukkala, 2017; Pukkala, 2018; Rüter et al, 2016; Seidl et al, 2007; Seppälä et al, 2019; Skytt et al, 2021; Smyth et al, 2014; Soimakallio et al, 2016, 2021; Valade et al, 2018; Zubizarreta‐Gerendiain, Pukkala, & Peltola, 2016) in step 1. A systematic literature review (SLR) (Tranfield et al, 2003) was carried out. SLR was chosen to complement the list of the relevant research papers from large mass and to minimise a possible bias in the results due to the authors' choice of papers.…”