EUCFLUX network

Comparison of Eucalyptus genetic material under contrasting environmental and silvicultural conditions The EUCFLUX network consists of 10 sites located along a gradient with contrasting soils (texture, slope). Each site (~3ha) comprises 16 plots installed between 2009 and 2018, and 9 additional plots installed from 2018 onwards. Each plot was planted with differing Eucalyptus genetic material in a regular grid pattern (3*2 m). The studied genotypes (25 per site) belong to different species of Eucalyptus (E. grandis, E. urophylla, E. camaldulensis, E. longirostrata, E. dunnii, E. pilularis, E. pelita, E. tereticornis) and their hybridses, clones and seminal material. One of the plots is planted with Corymbia citriodora. Between 2009 and 2018, 8 sites were paired (4 x 2) to ensure the maximum homogeneity of environmental conditions within each pair. Since 2018, the sites within each pair have been managed differently: one in coppice, the other as a regular high stand. This new phase makes it possible to study the two different types of management. Two sites were not paired (called unassociated sites). The two unassociated sites will be replanted for one, and uncut for the other, so that the behaviour of different Eucalyptus genotypes can be studied at one site far beyond the usual commercial rotation age (the trees will reach the age of 15 at the end of the cycle, while a typical rotation is only 6 years). The other replanted site will increase the number of sites to study the effects of soil gradients. The EUCFLUX Network offers the opportunity to quantify the importance of environmental conditions, genome and management for productivity and biogeochemistry in commercial Eucalyptus plantations. The number of genetic materials compared, the size of the individual plots and the quality of the monitoring carried out make this an important network for studies of this type at the global level. The EUCFLUX Network regularly monitors carbon fluxes and storage as well as productivity (carbon allocation, litterfall, gross primary productivity, wood production, soil CO2 emissions, soil carbon). Foliar ecophysiology (photosynthesis, stomatal conductance) and the environmental constraints that determine it, particularly water constraints, are also monitored at some sites for some of the materials. A meteorological station is located at the centre of the network. One of the objectives of the network is to link individual productivity or growth trajectories to simple functional traits both within genotypes (spatial variability) and among different genotypes (inter-genotypes).