Study site
Our study site was a 1.5-year-old provenance trial established in March 2022 at James Cook University’s Daintree Rainforest Observatory (DRO) in Cape Tribulation (−16.10449 °S, 145.4511 °E), Queensland, Australia. The provenance trial site has an area of 2,251 m2 and is surrounded by mature secondary forest regrowth. The plot used in this study is one of three set up across the Australian Wet Tropics bioregion to determine differences in growth and survival across upland and lowland provenances in 16 rainforest tree species (see Middleby et al., 2024b, for more information). At each site, seedlings of 16 species and provenance (upland and lowland for each species) were planted in a randomised block design (n = 32 plants per block × 10 blocks at each site) at a 1.5 × 3 m spacing (Middleby et al., 2024b). The DRO has a mean annual temperature (MAT) of 24.1 °C and a mean annual precipitation of 3516 mm (Karger et al., 2017), with the soils described as an acidic, dystrophic, brown dermosol, formed in the colluvium from the metamorphic and granitic mountains to the west (Murtha, 1989).