Leaf trait associations with environmental variation in the wide-ranging shrub Dodonaea viscosa subsp. angustissima (Sapindaceae) Part 1: Latitude 

Leaf traits for 101 populations of Dodonaea viscosa subsp. angustissima (Sapindaceae) opportunistically collected across a ~1,000 km latitudinal north-south sequence with climates grading from the arid zone to the mesic Mediterranean zone. Additionally, we present leaf traits for 266 individuals on an attitudinal gradient in the Mt Lofty Ranges, South Australia. Traits measured include leaf area and specific leaf area, as well as climatic variables associated with the collection sites. Leaf area is known to be responsive to climatic conditions. This data could be combined with additional collections for Dodonaea viscosa or broader plant trait data sets to explore pant responses to environmental change. 

We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging. 

The assessment of leaf area (LA) and specific leaf area (SLA) provides mechanistic insights on the persistence and function of plant species, including their likely success under climate change and their suitability for revegetation. We measured LA and SLA in the perennial shrub Dodonaea viscosa (L.) Jacq. subsp. angustissima (narrow-leaf hop-bush) (Sapindaceae) and correlate the variability in those traits to potential environmental drivers. We measured leaves from 104 populations in a ~1,000 km latitudinal north-south sequence with climates grading from the arid zone to the mesic Mediterranean zone. Regression, bootstrapping and principal component analysis related leaf traits to environment. 

Opportunistic sampling: We measured LA and SLA on either recently collected (fresh) or dried, preserved leaves. Samples came from one to five individuals per population and we analyzed five undamaged leaves per individual. We followed standard procedures for field sampling and preservation of fresh leaves (Pérez-Harguindeguy et al. 2013). We scanned the leaves and measured their area with ImageJ (Rasband 2011), before oven drying at 65°C for 48 hours, then weighing and calculating SLA. To account for the area contraction of preserved leaves, which made direct comparison with fresh samples impossible, we calculated a shrinkage factor by measuring fresh and dry LAs from two populations: one from a mesic site (Mt. Bryan 33.33° S; 139.05°E) and the other from an arid site (Andamooka 30.47° S; 137.15° E). Leaves from the northern and more arid site shrunk less (15.6 ± 2.4 %; n=20) than those from the wetter southern site (23.4± 4.3 %; n=25) (F(1,42) = 50.2; P<0.001). The mean shrinkage (20.1 ± 5.3 %) is consistent with published values (Torrez et al.2013; Queenborough & Porras 2014). Consequently, all LAs were converted to a fresh basis by: Fresh LA = Dry LA / 0.201 before SLA was calculated and further analysis Climatic and edaphic variables (Aridity index, Temp. Mean, Temp. Range, Soil N (nitrogen) content.,Soil P (phosphorus) content,%Clay, Bulk density and Solar Radiation) were extracted from the 1km gridded data available in the Atlas of Living Australia. PCA Axis 1 and PCA Axis 2 are derived from a Principal Component Analysis with the climate and edaphic variables used as predictors for Leaf Area and Specific Leaf Area.