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Forests are highly relevant for the water dynamics of mountain areas. This study assesses the water balance of two mountainous watersheds in Austria (Rindbach and Schmittental) with similar average annual precipitation patterns but different parent material, i.e., limestone in Rindbach versus greywacke in Schmittental. The biogeochemical mechanistic ecosystem model Biome-BGC with parameter settings developed for the central European tree species was obtained to assess the energy, nutrient, and water cycle as relevant for tree growth (=carbon cycle). The seasonal precipitation pattern, the snow accumulation, the evapotranspiration, the transpiration, the water-use efficiency, and the outflow are investigated. For the period 1960 to 2022, no precipitation trends are detectable, but a temperature increase of 1.9 °C in Rindbach and 1.6 °C in Schmittental is evident, leading to a declining snow accumulation. The model simulations suggest that transpiration and evapotranspiration rates increase with increasing LAI, indicating higher rates in Rindbach compared to Schmittental. The water use efficiency increases up to an LAI = 3 m2 m−2 and declines afterwards. The water balance variables follow the same pattern, i.e., with increasing LAI, the water outflow at the Rindbach catchment declines from 78% to 29% and from 72% to 31% in Schmittental. This confirms that forest cover is important to reduce water outflow and thus enhances the protection function of mountain forests.

Forests cover about 1/3 of Europe’s land area and are an important source in providing goods and services such as timber, drinking water, biodiversity, and carbon storage. They are important for a bioeconomy to mitigate climate change effects by reducing greenhouse gas emissions from the combustion of fossil fuels. The purpose of this paper is to assess Europe’s potential wood supply by harvesting system. Gridded forest characteristics data are combined with other European spatially-explicit data. A set of eight mechanized harvesting systems is applied to assess the “forest available for wood supply” (FAWS) in Europe. The results show that 74.9% of the total forest area in Europe can be considered FAWS and has the potential to be harvested under the current economic and technical harvesting conditions. The remaining forest area is under legal protection (4.3%) or has limited accessibility with the current mechanized harvesting systems (20.8%). Around 79% of the FAWS can be accessed with ground-based machinery, and another 16% if their operation range is extended using special attachments (e.g., chains or band) or winch-assisted systems. Around 5% of the FAWS is only accessible by cable yarding machinery. With the fully mechanized harvesting systems (i) harvester and forwarder and (ii) winch-assisted harvester and winch-assisted forwarder, about 80% of the harvestable forest area and growing stock can potentially be utilized.

Domestic wood production in Japan is low, and more than 60% of the wood consumed is imported. This is surprising because two-thirds of Japan’s land area is covered by forests. The dominant explanations for this low wood self-sufficiency rate are the lack of forest road infrastructure and the small-scale forest ownership structure. Austria is a country that is similar in topography and ownership structure but has a high wood self-sufficiency rate. Therefore, previous research has compared Japan to Austria. However, these studies did not address basic forest properties in much detail. This study uses national forest inventory data from both countries to assess the forest structures and utilization percentages of the annual wood increment. In contrast to the hypothesis, the results show that the two countries have similar increment rates. In contrast to former studies, the findings indicate that Japanese plantation forests have a higher timber stocking volume than Austrian forests. In Japan, the proportion of the standing volume in the 40–60-year-old age class is much higher compared to the other age classes, indicating an unbalanced growing stock. The results show that the utilization percentage is much higher in Austria (88%) than in Japan (53%). Therefore, the Japanese forest sector has a high potential to increase the harvest of wood.

Douglas fir is expected to play an increasingly important role in Swedish forestry under a changing climate. Thus far, seed orchards with clones of phenotypically selected trees (plus trees) have been established to supply the market with highly qualitative reproductive material. Given the high genetic variation of the species, its growth properties are significantly affected by the provenance. Here, we applied microsatellite markers to identify the origin of clones selected within the Swedish breeding programme. Moreover, we analysed the timing of bud burst in open-pollinated families of these clones. In particular, we aimed to explain the provenance effect on phenology by using molecular identification as a proxy. A Bayesian clustering analysis with microsatellite data enabled the assignment of the clones to one of the two varieties and also resolved within-variety origins. The phenological observations indicated an earlier bud burst of the interior variety. Within the coastal variety, the northern provenances exhibited a later bud burst. We found a significant effect of the identified origin on bud burst timing. The results of this study will be used to support further breeding efforts.

Competition for resources (light, water, nutrients, etc.) limits the size and abundance of live trees a site can support. This carrying capacity determines the potential carbon sequestration in live trees and the maximum growing stock. Lower stocking through thinning can change growth and mortality. We were interested in the relations between stand structure, increment, and mortality using a long-unmanaged oak-hornbeam forest near Vienna, Austria, as a case study. We expected lower increment for heavily thinned compared to unmanaged stands. We tested the thinning response using three permanent growth plots, in which two were thinned (50% and 70% basal area removed) and one remained unmanaged. We calculated stand structure (basal area, stem density, diameter distribution) and increment and mortality of single trees. Over ten years, the heavily thinned stand had a similar increment as that of the moderately thinned and unthinned stands. The basal area of the unthinned stand remained constant and stem density decreased due to competition-related mortality. The studied oak-hornbeam stands responded well even to late and heavy thinning, suggesting a broad “plateau” of stocking and increment for these forest types. Lower stem density for thinned stands led to a much larger tree increment of single trees, compared to the unthinned reference. The findings of this study need verification for other soil and climatic conditions.

In view of the increasing demand for forest resources in Europe, it is an option to foster the use of non-native tree species that can keep pace with the rapidly changing environmental conditions, such as Douglas-fir (Pseudotsuga menziesii). Thus, sufficient knowledge of how to manage such introduced species is highly required. In this study, we investigate theoretical silvicultural management options of Douglas-fir for forests in central Europe. We follow a three-step approach: (i) we collect the current central European management practices based on 434 Douglas-fir stands managed by 19 forest companies in Eastern Austria and Southern Germany using a survey. (ii) We calibrate and validate a Douglas-fir parameter set for the tree growth simulator MOSES so that we are able to (iii) simulate the silvicultural management options of Douglas-fir management. Our simulation results suggest: in mixed stands, Douglas-fir should be planted in mono-species patches. This leads to about six times higher productivity compared to a random arrangement. Natural regeneration is possible but requires active management at further development since the productivity might decrease up to 86% when growing in association with the highly competitive native tree species, Common beech (Fagus sylvatica). Intensive tending, as well as thinning, yields a surplus stem volume production of more than 30% in comparison with a moderate intervention. Even if our simulation results were not validated in the field, this analysis suggests that modeling as a heuristic tool is a useful instrument for forest managers in the decision-making process.

Forests are a key player within the global carbon cycle and reforestation is an important climate change mitigation mechanism. In this study, we identify potentially suitable areas for reforestation to assess the carbon sequestration potential in the highly deforested and degraded Amhara region of Ethiopia. We apply biogeochemical mechanistic ecosystem modelling to predict the amount of carbon that can be potentially sequestered within different time horizons. Since human intervention plays a key role within the Amhara region, three different forest management scenarios and five different rotation periods following reforestation are tested: (i) unthinned; (ii) removal of 5% of the stem carbon every 20 years (thinning 1); and (iii) removal of 10% stem carbon every 20 years (thinning 2), as well as a rotation period of 10, 30, 50, 100, and 150 years. Sustainable management of reforested land is addressed by implementing the so called ‘Normal-forest’ system (equal representation of every age class). This ensures the long term sequestration effect of reforested areas. The study shows that 3.4 Mha (Mha = Million hectare) of land, including bare land (0.7 Mha), grass land (1.2 Mha), and shrub land (1.5 Mha) can be considered as ecologically potentially suitable for reforestation. Assuming a 100 year rotation period in a ‘Normal-forest’ system, this shows that a total net carbon sequestration potential of 177 Tg C (10.8 Tg C in the soil and 165.9 Tg C aboveground; Teragram = 1012 g) is possible, if all 3.4 Mha are replanted. The highest total net carbon sequestration (soil and aboveground) was evident for the Highland-wet agro-ecological zone, whereas the lowest values are typically in the Midland-dry zone. The highest net aboveground carbon sequestration was predicted for reforestations on current grass land and shrub land versus bare land, whereas the highest net soil carbon sequestration was predicted on current bare land, followed by grass land and shrub land.