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Towards resource-efficient forests: Mixing species changes crown biomass allocation and improves growth efficiency
Get PDFSocietal Impact Statement
Forests worldwide face significant challenges due to climate change, impacting their health and productivity. In this study, we examined how European beech and Scots pine influence each other's phenology and growth in mixed forests. Our findings indicate that mixing these complementary tree species can increase resource efficiency within forest ecosystems. By leveraging informed species selection, this research highlights the potential for developing knowledge-based, resource-efficient forests. These insights are invaluable for policymakers and forest managers in designing forests that are not only productive but also sustainable and adaptable to evolving environmental conditions.
Summary
We investigated the effects of interspecific neighbors on crown morphology and growth efficiency in European temperate forests, specifically focusing on European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.). Our goal was to determine whether the previously reported overyielding in this mixture is primarily due to improved space-use efficiency and packing density or enhanced resource-use efficiency.
Our methodology involved a detailed analysis of 128 individual felled trees. We assessed the effect of intraspecific and interspecific neighbors on stem volume growth, the allometric relationships of tree crowns and their components, and the allocation of branch and leaf biomass along the trees' vertical structure.
Our findings demonstrate that interspecific neighbors significantly influence the allometric relationships of tree crowns, especially altering the vertical biomass distribution in European beech. Additionally, we found that interspecific neighbors can significantly enhance the growth efficiency of European beech but not for Scots pine.
This research provides valuable insights for enhancing forest growth models and guiding forest management practices. By understanding the critical role of crown biomass allocation and growth efficiency in mixed-species stands, policymakers and forest managers can design forests that are both productive and adaptable to changing environmental conditions. This study emphasizes the importance of species interactions in forest dynamics and bridges theoretical concepts with practical applications.202
Root rot increases the vulnerability of Norway spruce trees to Ips typographus infestation
Get PDFNorway spruce (Picea abies) is one of the most economically important tree species in Northern and Central Europe. Root rot caused by Heterobasidion annosum s.l. and the European spruce bark beetle (Ips typographus) are major disturbance agents of Norway spruce and are expected to increasingly affect spruce-dominated forests as the climate warms. This study investigated the direct interaction between root rot and I. typographus, with the aim of examining whether root rot and the stress it causes to a tree increases the risk of subsequent bark beetle attack. In total, 442 Norway spruce trees from nine different mature, even-aged forest stands were studied. First, symptoms caused by I. typographus were evaluated before final felling from each tree based on visual assessments of crown and stem conditions. After the felling, the sample plots were relocated from the clearcut areas, and the stumps of sampled trees were reassessed for root rot. Exploratory analysis and binomial Generalized Linear Mixed Model (GLMM) were used to analyze relationships between explanatory variables and their effect to I. typographus infestation. The best predictors for I. typographus infestation at individual tree level were presence of root rot and to a lesser extent, tree diameter at breast height. Seventy-five percent of root rot-infected trees were also infested with I. typographus, and most of those trees were either dead or severely infested. Results suggest that root rot weakens trees, making them more vulnerable to subsequent I. typographus infestation, especially early in outbreaks when bark beetle population densities are low
Biodiversity
Get PDFThis chapter summarises biodiversity responses to continuous cover forestry (CCF). The comparator throughout this chapter is rotation forestry (RF) and its main harvesting method—clearcutting—unless otherwise stated.
Research on the biodiversity effects of logging methods applied in CCF (mostly selection or gap cutting) mainly concerns the short-term effects of measures taken in mature, originally fairly even-aged forests, at best 10–15 years after cutting. Thus far, no surveys or chronosequences cover the whole rotation period (60–100 years).
Continuous cover forestry is likely to benefit species that suffer when the tree cover is removed, such as bilberry and its associated species. Species requiring spatial continuity in host trees or canopy cover may also benefit.
Selection cutting may preserve the majority of species in the mature forest, but the most sensitive species may decline or even disappear. Gap cutting (diameter 20–50 m) affects forest-interior species relatively little, but species’ abundances in gaps change with increasing gap size. Shelterwood cutting seems to closely resemble selection cutting in terms of species responses. In the long term, however, shelterwood cutting results in an even-aged and sparse overstorey, which does not produce the biodiversity benefits of CCF.
Species that have declined due to forestry mostly require large living and dead trees. The preservation of these species is not ensured by CCF alone, but requires deliberately maintaining these structural features.
A mosaic of different forest-management practices within landscapes may provide complementary ways to maintain rich biodiversity
Guidance for environmental footprint assessment of food products (Food-LCA) : Specification for external communicational purposes on the Finnish market, 2nd edition
Get PDFGuidance for environmental footprint assessment of food products (Food-LCA) - Specification for external communicational purposes on the Finnish market is a national guidance based on Life Cycle Assessment (LCA). It is targeted for conducting voluntary environmental footprints assessments for food products. The guidance is based on the European Commission’s (EC) Product Environmental Footprint (PEF) method (EC 2021), but it aims to cover widely the whole food product category and it includes national specifications compared to the PEF. Therefore, this guidance is not fully corresponding with the PEF method.
Food-LCA guidance aims to harmonize the LCA of food products’ environmental footprints in Finland, thereby promoting the comparability, reliability, and transparency of environmental footprints. This guidance has been prepared by researchers from the Natural Resources Institute Finland (Luke) as part of the LCAFoodPrint project (2021-2025). More information: https://www.luke.fi/en/projects/lcafoodprint. A wide group of professionals from the food sector including companies, ministries, research institutes, and other stakeholders were involved in commenting and development of this guidance
Financial Performance
Get PDFFinancial comparisons between rotation forestry (RF) and continuous cover forestry (CCF) are based on simulations in which the growth and yield of trees is estimated using a growth simulator. These often include an optimisation tool to present the maximum value of the objective function (usually the present value of net income).
Studies have shown that the profitability of CCF depends on the initial state of a stand, especially the diameter distribution of the trees. The effect of interest discount rate also depends on the initial state.
As a rule, it is safe to say that the more the forest structure resembles the target diameter distribution of the trees in CCF (i.e., a forest with heterogeneous structures), the more profitable it is to shift from RF to CCF.
The more heterogeneous the tree structure on mineral soil, the higher the applied interest rate, the higher the forest establishment costs (soil preparation and cultivation), and the poorer the growth conditions (site type and temperature sum), the more profitable CCF is. Few studies have been found that focus on peatland forests.
Future financial studies should also consider risks associated with wind, harvesting, and insect and fungus damage as well as carbon payments and nontimber benefits
Uneven-aged and even-aged forest management shape the soil fungal community composition in a boreal Norway spruce (Picea abies Karst) forest
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Small area estimators in a simulation test
Get PDFThe Finnish National Forest Inventory produces municipality level results either with an indirect model-based K-nearest neighbor (K-NN) estimator or a direct design-based post-stratification estimator. Design-based approach is unbiased, but not always feasible due to low number of field plots. The K-NN estimator is lacking an analytical estimator for the variance. A composite estimator combining the indirect and direct estimates could be an attractive solution. In this article, estimators for small-area estimation are analyzed in a simulation experiment with varying size small areas and varying quality auxiliary data. The potential of estimators is assessed based on the true standard errors and RMSEs in the simulation experiment. Direct estimators and composite estimators work reasonably well with varying quality models, but the performance of indirect estimators is dependent on the quality of the model used. The performance of different estimators also depends on the size of the small areas. Linear models in which the weight of plots outside the target domain is smaller than those within the target domain, performed better than an unweighted model, suggesting that localizing the models for the small areas is beneficial. EBLUP approach also performed well, both in connection of a K-NN model and a linear model