CONTRASTING LEVELS OF COMPETITION
Understanding how the different species planted at the IMPACT OAL respond to developing levels of environmental and physiological stress is a core goal of our research. This has been approached by planting the trees at very different spacing intensities (Figure 1) to subject them to different levels of competition. At the IMPACT OAL, there are four spacings for the single-species (i.e. E. cladocalyx, E. cloeziana, E. grandis and E. urophylla) seedling plots: 1 m2, 2 m2, 3 m2 and 5 m2 simulating a stand density of 10 000, 2 500, 1 111 and 400 trees per ha, respectively. As for the E. grandis clone the same spacings are used, but the 5 m2 spacing is excluded. All plots are replicated three times and randomised by spacing and varieties
Figure 1. Illustration of the differences in stand density between the spacing treatments. Trees will experience high levels of competition in the denser spacings (e.g. 1 m2) relative to the more open spacings (e.g. 5 m2).
