Leaf trait associations with environmental variation in the wide-ranging shrub Dodonaea viscosa subsp. angustissima (Sapindaceae) Part 2: Elevation 

Leaf traits for 11 populations of Dodonaea viscosa subsp. angustissima (Sapindaceae) opportunistically collected from across an elevational gradient (300 to 800 m above sea level) in the Flinders Ranges of South Australia. We present leaf traits for 266 individuals. Traits measured include leaf area and specific leaf area, and elevation. 

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 11 elevational populations (300 to 800 metres above sea level), where aridity and temperature decrease with elevation. Regression, bootstrapping and principal component analysis related leaf traits to environment. 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 plant responses to environmental change. 

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.