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De netto‑uitstoot van broeikasgassen in de Europese Unie moet met minstens 55% naar omlaag tegen 2030. Om dit ambitieuze doel te bereiken, moet minder CO2 worden uitgestoten én meer koolstof worden opgeslagen. Vóór 2030 wil Europa netto minstens 310 miljoen ton CO2-equivalent broeikasgassen verwijderen uit de atmosfeer door extra opslag van koolstof in landbouwgronden en bossen. Bossen nemen van nature CO2 op en leggen koolstof vast. Als bomen sterven of worden geoogst, verdwijnt een deel ervan. Het beheer van een bos kan de opslag van koolstof dus beïnvloeden. Zorgt nulbeheer, waarbij je bossen spontaan laat ontwikkelen, voor extra koolstofopslag? We bekeken het potentieel voor bovengrondse koolstofopslag in Vlaamse bossen, zowel in levende bomen als in dood hout. We berekenden hoeveel koolstof aanwezig is én hoeveel koolstof er jaarlijks bijkomt. Hiervoor gebruikten we gegevens van de eerste en tweede Vlaamse Bosinventaris (opgemeten door Natuur en Bos) en van de eerste en tweede monitoring in Vlaamse bosreservaten (door het INBO).

TreeDivNet is the largest network of biodiversity experiments worldwide, but needs to expand. We encourage colleagues to establish new experiments on the relation between tree species diversity and forest ecosystem functioning, and to make use of the platform for collaborative research.

Forest ecosystem multifunctionality and the provision of ecosystem services benefit from high biodiversity, including from the understorey. Hence, it is crucial to get insight into the mechanisms that influence the composition and diversity in this forest layer. Understorey species have specific environmental requirements which are influenced by the overstorey in a species-specific way. Mixing tree species may create a heterogeneous pattern of environmental conditions similar to the component species’ monocultures, or induce new environmental conditions. We quantified overstorey–understorey taxonomic and functional diversity relationships at different spatial scales in an innovative large-scaled European diversity-oriented research platform that allows the separation of tree species identity and diversity effects. We considered our results in relation to the divergent patterns expected, depending on whether environmental heterogeneity or novel environment creation is the mechanism driving overstorey–understorey diversity relationships.We examined the understorey in mature forests in six European regions. Per region, three to five tree species were selected and 28–43 plots of 30 m × 30 m were established (209 in total), covering a tree species richness gradient from monocultures to three- to five-species mixed plots. Within each plot, we performed vegetation surveys in three vegetation quadrats. We examined the understorey compositional variation among and within regions and the influence of overstorey taxonomic and functional diversity on understorey diversity at different spatial scales.The understorey composition showed clear interregional differences. We found lower compositional differentiation among quadrats with a higher tree species richness level (Finland, Germany and Italy). These quadrats share more tree species and probably have more similar environmental conditions. Neither overstorey taxonomic nor functional diversity

Mixing of complementary tree species may increase stand productivity, mitigate the effects of drought and other risks, and pave the way to forest production systems which may be more resource-use efficient and stable in the face of climate change. However, systematic empirical studies on mixing effects are still missing for many commercially important and widespread species combinations. Here we studied the growth of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in mixed versus pure stands on 32 triplets located along a productivity gradient through Europe, reaching from Sweden to Bulgaria and from Spain to the Ukraine. Stand inventory and taking increment cores on the mainly 60–80 year-old trees and 0.02–1.55 ha sized, fully stocked plots provided insight how species mixing modifies the structure, dynamics and productivity compared with neighbouring pure stands. In mixture standing volume (+12 %), stand density (+20 %), basal area growth (+12 %), and stand volume growth (+8 %) were higher than the weighted mean of the neighbouring pure stands. Scots pine and European beech contributed rather equally to the overyielding and overdensity. In mixed stands mean diameter (+20 %) and height (+6 %) of Scots pine was ahead, while both diameter and height growth of European beech were behind (−8 %). The overyielding and overdensity were independent of the site index, the stand growth and yield, and climatic variables despite the wide variation in precipitation (520–1175 mm year−1), mean annual temperature (6–10.5 °C), and the drought index by de Martonne (28–61 mm °C−1) on the sites. Therefore, this species combination is potentially useful for increasing productivity across a wide range of site and climatic conditions. Given the significant overyielding of stand basal area growth but the absence of any relationship with site index and climatic variables, we hypothesize that the overyielding and overdensity results from several different types of i

The area of forest plantations is increasing worldwide helping to meet timber demand and protect natural forests. However, with global change, monospecific plantations are increasingly vulnerable to abiotic and biotic disturbances. As an adaption measure we need to move to plantations that are more diverse in genotypes, species, and structure, with a design underpinned by science. TreeDivNet, a global network of tree diversity experiments, responds to this need by assessing the advantages and disadvantages of mixed species plantations. The network currently consists of 18 experiments, distributed over 36 sites and five ecoregions. With plantations 1–15 years old, TreeDivNet can already provide relevant data for forest policy and management. In this paper, we highlight some early results on the carbon sequestration and pest resistance potential of more diverse plantations. Finally, suggestions are made for new, innovative experiments in understudied regions to complement the existing network.

Mixing of complementary tree species may increase stand productivity, mitigate the effects of drought and other risks, and pave the way to forest production systems which may be more resource-use efficient and stable in the face of climate change. However, systematic empirical studies on mixing effects are still missing for many commercially important and widespread species combinations. Here we studied the growth of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in mixed versus pure stands on 32 triplets located along a productivity gradient through Europe, reaching from Sweden to Bulgaria and from Spain to the Ukraine. Stand inventory and taking increment cores on the mainly 60–80 year-old trees and 0.02–1.55 ha sized, fully stocked plots provided insight how species mixing modifies the structure, dynamics and productivity compared with neighbouring pure stands. In mixture standing volume (+12 %), stand density (+20 %), basal area growth (+12 %), and stand volume growth (+8 %) were higher than the weighted mean of the neighbouring pure stands. Scots pine and European beech contributed rather equally to the overyielding and overdensity. In mixed stands mean diameter (+20 %) and height (+6 %) of Scots pine was ahead, while both diameter and height growth of European beech were behind (−8 %). The overyielding and overdensity were independent of the site index, the stand growth and yield, and climatic variables despite the wide variation in precipitation (520–1175 mm year−1), mean annual temperature (6–10.5 °C), and the drought index by de Martonne (28–61 mm °C−1) on the sites. Therefore, this species combination is potentially useful for increasing productivity across a wide range of site and climatic conditions. Given the significant overyielding of stand basal area growth but the absence of any relationship with site index and climatic variables, we hypothesize that the overyielding and overdensity results from several different types of i

Context - During the last two decades, functional biodiversity research has provided strong support for the hypothesis that more biodiverse ecosystems have the potential to deliver more and better services. However, most empirical support for this hypothesis comes from simple structured communities that are relatively easy to manipulate. The impact of forest biodiversity on forest ecosystem functioning has been far less studied. Experiment design - In this paper, we present the recently established, large-scale FORBIO experiment (FORest BIOdiversity and Ecosystem Functioning), specifically designed to test the effects of tree species diversity on forest ecosystem functioning. FORBIO's design matches with that of the few other tree diversity experiments worldwide, but at the same time, the FORBIO experiment is unique as it consists of a similar experimental set-up at three sites in Belgium (Zedelgem, Hechtel-Eksel and Gedinne) with contrasting edaphic and climatological characteristics. This design will help to provide answers to one of the most interesting unresolved questions in functional biodiversity research, notably whether the effects of complementarity on ecosystem functioning decrease in less stressful and more productive environments. At each site, FORBIO consists of 41 to 44 plots (127 plots in total) planted with monocultures and mixtures up to four species, selected from a pool of five site-adapted, functionally different tree species. When allocating the treatments to the plots, we maximally avoided any possible covariation between environmental factors. Monitoring of ecosystem functioning already started at the Zedelgem and Gedinne sites and will start soon in Hechtel-Eksel. Multiple processes are being measured and as the trees grow older, we plan to add even more processes. Expected results - Not only basic science, but also forest management will benefit from the results coming from the FORBIO experiment, as FORBIO is, for instance, also a test case, SCOPUS: ar.j, info:eu-repo/semantics/published

Voor een aantal semi-natuurlijke vegetatietypes, zoals droge en natte graslanden of heiden, vormen de hoge nutriëntenvoorraden in de bodem als gevolg van de vroegere bemesting vaak een belangrijk knelpunt. Of dit voor de ontwikkeling van bosvegetaties ook geldt, wordt in dit artikel geïllustreerd aan de hand van resultaten uit twee introductie-experimenten met enkele voor oude bossen kenmerkende plantensoorten. Een bijdrage vanuit Universiteit Gent, Leuven en het Vlaams Instituut voor het Onroerend Erfgoed

Amerikaanse vogelkers wordt beschouwd als een invasieve exoot. Doordat de soort over grote oppervlakten en in grote aantallen werd geïntroduceerd, kon de soort zich sterkt uitbreiden. Maar hoe zou Amerikaanse vogelkers zich gedragen zonder deze uitgangssituatie? Bosreservaten waarin niet beheerd wordt, bieden de mogelijkheid om spontane bosontwikkeling te bestuderen. In het bosreservaat Liederkerke (Vlaanderen) heeft Amerikaanse vogelkers zich ongeveer 40 jaar geleden spontaan gevestigd, waarschijnlijk uit zaden die achtergelaten werden door vogels. Sindsdien heeft de soort zich ongestoord kunnen ontwikkelen. Een reconstructie van het kolonisatieproces met aanbevelingen voor beheer

Pro Silva Vlaanderen was op zoek naar een herbronning van vogelkersbestrijding en organiseerde in het voorjaar van 2009 twee excursies. Hierop waren veel deelnemers van Pro Silva Nederland aanwezig; ook in Nederland is het thema vogelkersbestrijding – na 50 jaar bestrijden – nog steeds actueel. Op de excursie van 15 mei werden experimenten met heupkap in Duinoord besproken, op 6 juni de goedgedocumenteerde bestrijding in Ophovenerheide. In dit artikel geven we een verslag van beide excursies en bespreken we de geschiedenis van Amerikaanse vogelkers in West-Europa. We gebruikten het uitgebreide artikel van Starfinger et al. (2003) als basis en voegden resultaten uit recent onderzoek toe. Hoe komt het dat er zo veel Amerikaanse vogelkers in onze bossen staat? Waarom bestrijden we Amerikaanse vogelkers eigenlijk?

In dit artikel vindt u de resultaten van een enquête over de bestrijding van Amerikaanse vogelkers bij 30 terreinbeheerders in Vlaanderen.