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).