2.2 Study species and plant material
We selected 16 tropical rainforest tree species (Figure 1, Table S1,
Figure S1) that are commonly used in revegetation plantings in the
Australian Wet Tropics bioregion (Engert et al. 2020),
taxonomically diverse (representing 13 families), and exhibit a broad
range of plant functional traits and successional strategies (Goosem &
Tucker 2013). Plant material with verified coordinates or collection
location descriptions were sourced from local nurseries including Cairns
Regional Council, Rainforest Rescue, Douglas Shire Council, Tablelands
Regional Council, and Kuranda Envirocare. For each species, we obtained
30 individual seedlings from either lowland or upland origin (n =
960 = 30 seedlings × 2 provenance × 16 species). For two species
(Davidsonia pruriens and Syzygium kuranda ) only 15
seedlings could be sourced from a single upland maternal location so
seedlings from an additional upland maternal location were included to
make up the 30 total replicate seedlings needed (Table S1). During
seedling handling and planting, we made sure plant provenance could be
tracked back to the maternal plant location, however for this study we
consider any plants originating from above 300 m a.s.l to be of ‘upland
provenance’ and any plants originating from below this threshold to be
of ‘lowland’ provenance in downstream analyses.
Across the focal species, the lowland and upland provenances differed in
their MAT by on average 4.0 °C (range 1.8 to 5.8 °C) and by 836 mm in
their MAP (range 102 to 1890 mm) (Table S1). Lowland and upland
provenance collection locations were on average 105 km (range 52 to 150
km) apart (great-circle distance calculated with ‘geosphere’ package
(Hijmans 2022)), with Lowland provenances sourced from the Daintree
Rainforest and upland provenances sourced from the Atherton tablelands
(with few exceptions). As such, the comparison between DRO and Thiaki
planting sites represented a reciprocal transplant for many species.