Pubblicazioni dell'IFN
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Avitabile V., Pilli R., Migliavacca M., Duveiller G., Camia A., Blujdea V., … Thürig E. (2024) Harmonised statistics and maps of forest biomass and increment in Europe. Sci. Data. 11, 274 (17 pp.). https://doi.org/10.1038/s41597-023-02868-8
Forest biomass is an essential resource in relation to the green transition and its assessment is key for the sustainable management of forest resources. Here, we present a forest biomass dataset for Europe based on the best available inventory and satellite data, with a higher level of harmonisation and spatial resolution than other existing data. This database provides statistics and maps of the forest area, biomass stock and their share available for wood supply in the year 2020, and statistics on gross and net volume increment in 2010–2020, for 38 European countries. The statistics of most countries are available at a sub-national scale and are derived from National Forest Inventory data, harmonised using common reference definitions and estimation methodology, and updated to a common year using a modelling approach. For those counties without harmonised statistics, data were derived from the State of Europe's Forest 2020 Report at the national scale. The maps are coherent with the statistics and depict the spatial distribution of the forest variables at 100 m resolution.
DOI: 10.1038/s41597-023-02868-8
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Bont L.G., Schweier J., Temperli C. (2024) Effect of labour costs on wood harvesting costs and timber provision. Eur. J. For. Res. 143, 393-418. https://doi.org/10.1007/s10342-023-01621-5
Efficient forest operations are essential for forest enterprises, who provide wood and numerous ecosystem services for the society. Important factors influencing the efficiency of forest operations, and thus the harvesting costs, are the level of mechanization, the harvesting method applied, the forest road network, and the training of the labourers. The cost of labour, i.e. salaries, is another important driver of harvesting costs. However, its effect on and relative importance for overall harvesting costs is poorly described in the scientific literature. Thus, this study aims to analyse the influence of labour costs in more detail, especially on the country-wide wood harvesting potentials. In addition, we aimed to cross-compare the effect of labour costs with the effect of switching to a more efficient harvesting method. For this purpose, we calculated timber harvesting costs with varying salaries for all sample plots of the Swiss National Forest Inventory (NFI) for both, the currently applied harvesting method recorded in the NFI, and the potential best suitable harvesting method. A 1% change in labour costs affects harvesting costs by 0.33–0.77%, depending on the harvesting method applied. The influence is larger for systems that involve a large share of motor-manual work and for cable-based methods. Changing labour costs by ± 30% affects the number of plots for which timber harvesting is economically feasible, by 5 to 15 percent points. The effect of switching from the current to the best suitable harvesting method is comparable to that of reducing labour costs by 15–30%. These results indicate that the efficiency of wood harvesting can be increased with further mechanization and does not require cutting salaries of forestry personnel. In that, our results may inform forestry planning and policy making at regional to national level.
DOI: 10.1007/s10342-023-01621-5
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Bouchard E., Searle E.B., Drapeau P., Liang J., Gamarra J.G.P., Abegg M., … Paquette A. (2024) Global patterns and environmental drivers of forest functional composition. Glob. Ecol. Biogeogr. 33(2), 303-324. https://doi.org/10.1111/geb.13790
Aim: To determine the relationships between the functional trait composition of forest communities and environmental gradients across scales and biomes and the role of species relative abundances in these relationships.
Location: Global.
Time period: Recent.
Major taxa studied: Trees.
Methods: We integrated species abundance records from worldwide forest inventories and associated functional traits (wood density, specific leaf area and seed mass) to obtain a data set of 99,953 to 149,285 plots (depending on the trait) spanning all forested continents. We computed community-weighted and unweighted means of trait values for each plot and related them to three broad environmental gradients and their interactions (energy availability, precipitation and soil properties) at two scales (global and biomes).
Results: Our models explained up to 60% of the variance in trait distribution. At global scale, the energy gradient had the strongest influence on traits. However, within-biome models revealed different relationships among biomes. Notably, the functional composition of tropical forests was more influenced by precipitation and soil properties than energy availability, whereas temperate forests showed the opposite pattern. Depending on the trait studied, response to gradients was more variable and proportionally weaker in boreal forests. Community unweighted means were better predicted than weighted means for almost all models.
Main conclusions: Worldwide, trees require a large amount of energy (following latitude) to produce dense wood and seeds, while leaves with large surface to weight ratios are concentrated in temperate forests. However, patterns of functional composition within-biome differ from global patterns due to biome specificities such as the presence of conifers or unique combinations of climatic and soil properties. We recommend assessing the sensitivity of tree functional traits to environmental changes in their geographic context. Furthermore, at a given site, the distribution of tree functional traits appears to be driven more by species presence than species abundance.DOI: 10.1111/geb.13790
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Ferretti M., Fischer C., Gessler A., Graham C., Meusburger K., Abegg M., … Shackleton R.T. (2024) Advancing forest inventorying and monitoring. Ann. For. Sci. 81(1), 6 (25 pp.). https://doi.org/10.1186/s13595-023-01220-9
Forests are under pressure and going through rapid changes. However, current inventorying and monitoring (IM) programs are often either disjointed, too narrow in their scope and/or do not operate at fine enough temporal resolutions, which may hinder scientific understanding, the timely supply of information, fast decision making, and may result in the sub-optimal use of resources. For these reasons, there is an urgent need for Advanced Forest Inventorying and Monitoring (AIM) programs to (i) achieve expanded relevance (by augmenting data/information across ecosystem properties and trophic levels), (ii) have increased temporal resolution (by tailored data collection frequency), and (iii) make use of technological advances (by incorporating novel tools and technologies). The Advanced Inventorying and Monitoring for Swiss Forests (SwissAIM) initiative was launched in 2020 to address these needs. SwissAIM builds upon the foundation offered by the existing programs (e.g., national forest inventory, long-term forest ecosystem research, biodiversity monitoring). It aims to offer a collaborative and adaptive framework to enable integrated data collection, evaluation, interpretation, analysis, and modeling. Ideally, it will result in a more responsive system with respect to current and predicted biotic/abiotic stressors that will challenge Swiss forests. Developing such a system implies identifying the information needs of different stakeholders (e.g., science, policy, practice), related technical requirements, and governance frameworks. Here, we present (i) the main features of the SwissAIM initiative (vision, scientific questions and variables, governance and engagement), (ii) the main outcomes of the participatory design process (measurements, sampling, and plot design), (iii) the potential transferability of AIM initiatives outside Switzerland (timing, relevance, practicability), and (iv) the key messages that emerged (i.e., need for advancement, integration and transdisciplinarity, statistical underpinning). Since similar needs related to forest inventorying and monitoring are emerging throughout Europe and elsewhere, the objective of this opinion paper is to share our experience and promote a dialog with those interested in developing AIM initiatives in other countries and regions.
DOI: 10.1186/s13595-023-01220-9
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Kupferschmid A.D. (2024) Methodischer Vergleich und Zeitreihenanalysen zu Verbiss im Verjüngungskontext des LFI: Schlussbericht. Eidg. Forschungsanstalt für Wald, Schnee und Landschaft WSL. 16 p. https://doi.org/10.55419/wsl:36188
Die Baumverjüngung ist ein komplexer Prozess der stark von abiotischen und biotischen Faktoren beeinflusst wird wie z.B. dem Verbiss durch wildlebende Huftiere. Mittels der Schweizerischen Landesforstinventare (LFI) werden Aussagen zur zeitlichen Entwicklung des Verbisses in den letzten Jahrzehnten untersucht.
Da die Methode der Verjüngungserhebung zwischen LFI1 und LFI4 mehrmals gewechselt wurde, wurde im 1 Modul die Änderungen detailliert dokumentiert (1A) und mittels Simulationen deren Auswirkungen auf die Dichte der Verjüngung und des Verbisses aufgezeigt (1B). Es wird empfohlen, nur LFI2 (zusätzliche Reduktion auf nur 1 Subplot) mit LFI4 (bzw. LFI5) zu vergleichen und auch dies nur in einseitigen Test (Zunahme des Verbisses) bzw. Abnahmen im Verbiss müssen grösser als ca. 25% sein, damit sichergestellt ist, dass es kein Artefakt der Methodenänderung der Verbissansprache ist.
Das Modul 2 befasste sich mit der Ebene der Stratifizierung zur Auswertung des Verbisses im Schweizer Wald. Damit relevante Verbiss-Zu- oder Abnahmen festgestellt werden können, sind minimal 50 bestockte Probeflächen (N = 50) bzw. 100 Bäumchen je Aussageeinheit nötig. Die kantonal ausgeschiedenen Wildräume sind dafür zu klein. Es wird, in Anlehnung an die klassischen LFI-Gliederungen, die Verwendung der Schutzwaldregionen unter Aufteilung der Region «Jura + Mittelland» gemäss der biogeographischen Region «Jura» und den Wirtschaftsregionen «Mittelland West», «Mittelland Mitte» und «Mittelland Ost» vorgeschlagen.
Im 3. Modul wurden für alle Kantone verschiedene regionale Dichteschätzungen von wildlebenden Huftieren zusammengetragen. Insbesondere wurden Daten zu Abschuss und Fallwild für die Zeitspanne von 1983 bis 2017 aufbereitet und damit unterschiedliche Indexe (z.B. Ungulate Density Index und Faktoren zum Geschlechterverhältnis) berechnet.
Im Modul 4 wurden statistische Modelle berechnet zur zeitlichen Entwicklung des Verbisses unter Einbezug der Wildtierdichten. Exemplarisch sind die Resultate für die Weisstanne und 5 häufige Baumarten für die Regionen Jura, Mittelland Ost, Mittelland West + Mittelland Mitte, Nordalpen Ost und Nordalpen West vorgestellt. Je höher die Dichte der wildlebenden Huftiere mittels der Abschüsse und des Fallwildes eingeschätzt wurde (UDI), desto mehr Verbiss wurde festgestellt. Die Signifikanz der Faktoren zum Geschlechterverhältnis deuten auf die Wichtigkeit der Managementziele bezüglich Wildtierdichten (Zunahme, Stabilisation oder Abnahme der Wilddichten) hin. Der Verbiss hat im Laufe der Zeit an den (häufigen) Laubbaumarten abgenommen, nicht aber an der Weisstanne. [...]DOI: 10.55419/wsl:36188
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Leuch B.A., Abegg M., Scherrer D., Frehner M., Losey S. (2024) Vegetationshöhenstufen und Standorttypen im LFI: bisherige und neue Angaben im Vergleich. Schweiz. Z. Forstwes. 175(2), 64-71. https://doi.org/10.3188/szf.2024.0064
Im Rahmen des Projektes NaiS-LFI wurden in den Jahren 2014–2019 die Vegetationshöhenstufen und die Standorttypen auf den zugänglichen Waldprobeflächen des Schweizerischen Landesforstinventars (LFI) bestimmt. Dies geschah in der Systematik der Wegleitung «Nachhaltigkeit und Erfolgskontrolle im Schutzwald» (NaiS). So bietet sich die Möglichkeit zu analysieren, wie hoch die Übereinstimmung des Outputs der bislang im LFI verwendeten Definitionen und Modelle mit den auf den Probeflächen bestimmten NaiS-Vegetationshöhenstufen und -Vegetationseinheiten (= Gruppen von Standorttypen) ist. Bei den Vegetationshöhenstufen betrug die Übereinstimmung 76%. Bei den Vegetationseinheiten war sie mit 36% wesentlich geringer. Die NaiS-Vegetationshöhenstufen und -Vegetationseinheiten sind seit Juni 2023 als Klassifizierungsmerkmale in der LFI-Ergebnisabfrage im Internet verfügbar. Zudem werden in den Ableitungen, die sich auf Vegetationshöhenstufen oder Vegetationseinheiten stützen (z.B. zur Bestimmung der Naturnähe des Nadelholzanteils), neu die NaiS-Angaben verwendet.
DOI: 10.3188/szf.2024.0064
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Portier J., Shackleton R.T., Klesse S., Ferretti M., Flury R., Hobi M.L., … Thürig E. (2024) No evidence that coring affects tree growth or mortality in three common European temperate forest tree species. Eur. J. For. Res. 143, 129-139. https://doi.org/10.1007/s10342-023-01612-6
Tree cores are a highly valuable scientific resource. Annual growth ring data can, for example, improve our understanding of climate change impacts and effects of environmental pollution, allow for better annual estimations of tree growth patterns and carbon storage, and help quantify dynamics and changes in forest ecosystems. The value of coring trees for research has been weighted against concerns around the potential harm coring might cause to trees. To date, there is indeed limited research accurately quantifying the potential effects of coring on tree growth and only a handful of studies assessing its influence on mortality. Consequently, many European long-term forest inventorying and monitoring programs are concerned that tree coring might bias the repeated tree measurements in permanent plots, which they rely on for assessments of states and changes of forests. In this study, we assessed the effects of tree coring on the growth and mortality of three widespread European tree species approximately 10 years after they were cored. We used repeated tree measurements from permanent research sites in Switzerland and Ukraine. In Switzerland, we assessed 35 cored and 159 uncored Norway spruce (Picea abies) trees as well as 147 cored and 332 uncored silver fir (Abies alba) trees. In Ukraine, we assessed 348 cored and 6'611 uncored European beech (Fagus sylvatica) trees. We found no statistical evidence that coring negatively affected the growth or mortality of the three tree species assessed. Although we cannot rule out subtle effects on tree health and wood quality, our findings do not provide any evidence that coring affects or biases repeated measurements (such as DBH measures and recording of mortality) performed on the investigated tree species. Tree coring could therefore be considered more often for routine incorporation, particularly in long-term forest inventorying and monitoring programs and initiatives.
DOI: 10.1007/s10342-023-01612-6