Experiment
To evaluate the impact of increasing tree diversity on ecosystem functioning, a highly innovative large-scale forest biodiversity experiment has been established. On three different experimental sites, plots with synthetic communities of single species and plots with increasing tree species richness were installed. When fully grown, differences in various aspects of ecosystem functioning in plots that have developed under the same abiotic circumstances can be related with different tree diversity levels. The sites are located in Zedelgem (Flanders), Gedinne (Wallonia) and Hechtel-Eksel (Flanders, still to be established).
Basic design
The basic experimental design is the same for each of the study sites: 40 plots of 42 m x 42 m are established and the species diversity varies from 1 to 4 species. There are 5 plots for every of the four diversity levels and two replications. Tree species are planted in patches of at least 9 individuals, with a planting density of 1.5 m x 1.5 m. For each site a species pool of 5 functionally dissimilar, but site-adjusted species was selected.
A genetic diversity component has been added as well. In one of the series of 20 plots, one species was planted as 3 different genetic provenances. In the other series, only one provenance was used for that species. The different provenances were also (twice) added as a monoculture plot. This resulted in 42 plots in Zedelgem and 44 plots in Gedinne (and in Hechtel-Eksel in the near future).
All species occur in similar frequency (20/40), and all two-species combinations occur in similar frequency as well (10/40). Before attributing species combinations to plots, an extensive soil survey was executed. The treatments and replications were attributed to the experimental plots so that no covariation existed between any of the soil variables on the one hand and the presence/absence of a tree species on the other hand.
Characteristics of the different sites
| Zedelgem (Flanders) | ||
|---|---|---|
| Local name | Vloethemveld |  |
| Area | 9.5 ha | |
| Owner | Flemish region | |
| Former land use | Agriculture (arable land) | |
| Altitude | 11-16 m | |
| Soil type | Relatively dry sandy soil (Zbh) to moderately wet loamy sand soil (SdP) | |
| Planting date | 3-5/12/2009 and 24-27/03/2010 | |
| Speciespool | Fagus sylvatica, Betula pendula, Pinus sylvestris, Tilia cordata, Quercus robur (1 vs 3 provenances). | |
| Local manager | Agentschap voor Natuur en Bos (ANB) | |
| Site manager | Prof. Kris Verheyen (Department of Forest and Water management, Ghent University) | |
| Gedinne (Wallonia) | ||
| Local name | Gribelle and Gouverneurs |   |
| Area | 2 x 4.5 ha | |
| Owner | Town of Gedinne | |
| Former land use | Forest: spruce plantations | |
| Altitude | 367-376 m (Gribelle) and 421-426 m (Gouverneurs) | |
| Soil type | Moderately dry stony loam soils (Gbb; both sites) | |
| Planting date | April-May 2010 | |
| Speciespool | Acer pseudoplatanus, Pseudotsuga menziesii, Larix x eurolepis, Quercus petraea, Fagus sylvatica (1 vs 3 provenances). | |
| Local manager | Division de la Nature et les forêts (DNF) | |
| Site manager | Prof. Quentin Ponette (Department of Environmental Sciences and Land Use, University of Louvain-La-Neuve) | |
| Hechtel-Eksel (Flanders) | ||
| Local name | Pijnven | To be determined |
| Planting date | Later in 2011 | |
| Site manager |
Prof. Kris Verheyen (Department of Forest and Water management, Ghent University) |
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More details about experimental sites and design can be found in the final report of FORBIO for SSD (outputs). Details
Research
Due to the slow development of forest ecosystems, no research results of the experimental sites are available yet. On the longer run, this experiment will potentially yield very valuable outputs. Several research projects have already started on the sites (research).
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Are you interested to do research within the FORBIO framework? Contact one of our partners to talk about research options! |
