Data from: Quantifying the effects of ecological constraints on trait expression using novel trait-gradient analysis parameters
Ottaviani, Gianluigi, University of Western Australia
Tsakalos, James L., University of Western Australia
Keppel, Gunnar, University of Western Australia
Mucina, Ladislav, University of Western Australia, Stellenbosch University
Published Oct 17, 2018 on Dryad.
Cite this dataset
Ottaviani, Gianluigi; Tsakalos, James L.; Keppel, Gunnar; Mucina, Ladislav (2018). Data from: Quantifying the effects of ecological constraints on trait expression using novel trait-gradient analysis parameters [Dataset]. Dryad. https://doi.org/10.5061/dryad.23fg0
1. Complex processes related to biotic and abiotic forces can impose limitations to assembly and composition of plant communities. Quantifying the effects of these constraints on plant functional traits across environmental gradients, and among communities, remains challenging. We define ecological constraint (Ci) as the combined, limiting effect of biotic interactions and environmental filtering on trait expression (i.e., the mean value and range of functional traits).
2. Here we propose a set of novel parameters to quantify this constraint by extending the trait-gradient analysis (TGA) methodology. The key parameter is ecological constraint, which is dimensionless and can be measured at various scales, e.g., on population and community levels. It facilitates comparing the effects of ecological constraints on trait expressions across environmental gradients, as well as within and among communities.
3. We illustrate the implementation of the proposed parameters using the bark thickness of 14 woody species along an aridity gradient on granite outcrops in southwestern Australia. We found a positive correlation between increasing environmental stress and strength of ecological constraint on bark thickness expression. Also, plants from more stressful habitats (shrublands on shallow soils and in sun-exposed locations) displayed higher ecological constraint for bark thickness than plants in more benign habitats (woodlands on deep soils and in sheltered locations).
4. The relative ease of calculation and dimensionless nature of Ci allow it to be readily implemented at various scales and make it widely applicable. It therefore has the potential to advance the mechanistic understanding of the ecological processes shaping trait expression. Some future applications of the new parameters could be investigating the patterns of ecological constraints i) among communities from different regions, ii) on different traits across similar environmental gradients, and iii) for the same trait across different gradient-types.
Ottaviani et al 2017_Ecol Evol_bark thickness data
Bark thickness data were collected in the field for 14 plant species, from seven granite outcrops across an aridity gradient in Southwestern Australia, in 2012. In each study site, 3-4 species were sampled. For each species 10 individuals were sampled (in each outcrop). For each plant sampled, 5 different bark thickness measurements were collected, then averaged.