DOI: 10.5061/dryad.q83bk3jtj
title: Scale-dependent variation in leaf functional traits clarifies mechanisms of invasion

description: Comparing the functional traits of co-occurring native and invasive plant
 species can offer insight regarding mechanisms of invasion. Previous
 studies have failed to reach a consensus, indicating that the extent of
 trait differences between native and invasives might depend on the
 environmental context and on the spatial grain of the analysis. Here we
 evaluate the scale-dependency of native-invader trait comparisons within
 the Hawaiian Archipelago, a globally important region of high endemicity
 and high invasibility. We evaluated trait (e.g. gas exchange, leaf
 nutrient concentration, specific leaf area) differences locally and
 regionally (i.e. within and across islands) and found that while invasives
 are more resource acquisitive at the regional scale, native-invader
 differences are highly idiosyncratic at localized scales, varying both in
 direction and magnitude within islands. Our findings clarify how
 region-wide species comparisons may fail to characterize interactions
 happening at local scales, thereby misleading or obscuring the mechanisms
 underlying invasion.
description: Morphological and physiological traits were measured on
 individual plants of native Hawaiian species and non-native invasive
 species across a range of sites in Hawaii. The dataset includes 21 sites
 across four of the Hawaiian Islands, with a total of 87 species. We
 removed obvious outliers or unreasonable values, including negative
 photosynthesis, transpiratoin, or stomatal conductance, and extreme values
 of specific leaf area (SLA). Leaf chlorophyll content was measured on
 three leaves per individual and averaged together to produce one value per
 individual. The remaining traits were measured on one leaf per individual.
 Individual replicates were averaged to site level and island level for
 statistical analyses in our manuscript. All variables were then log10
 transformed, with the exception of soil pH, because it is already on a
 logarithmic scale. The final dataset includes the logscaled data rather
 than the raw data.
description: # Scale-dependent variation in leaf functional traits clarifies mechanisms
 of invasion
 [https://doi.org/10.5061/dryad.q83bk3jtj](https://doi.org/10.5061/dryad.q83bk3jtj) ## Description of the data and file structure Plant functional trait data were collected on native Hawaiian species and co-occurring non-native invasives between 2016 and 2017. 87 species were measured across 21 sites that spanned four Hawaiian Islands. The dataset includes primarily woody species sampled on intact evergreen forest. We measured 11 plant traits, including morphological and physiological traits, on individual plants. The dataset also includes soil and climate data extracted from previous datasets using the spatial coordinates of individual plants. All the plant traits and environmental variables were log10 transformed, with the exception of soil pH.  ### Files and variables #### File: DRYAD\_dataframe.xlsx **Description:** This file contains all 11 functional traits measured at the level of individual plants from 87 native and invasive species in Hawaii. It also contains six environmental variables, which were extracted from previously published gridded datasets using the spatial coordinates of the individual plants in the dataset. The variables have been log10 transformed with the exception of soil pH. Missing values or values that were excluded because they were deemed statistical outliers (or unreasonably high/low) were set to "NA". ##### Variables | Variable | Description | | :------------------- | :---------------------------------------------------------------------------------------------------------------------------------------- | | Species | Genus and species | | Location | Site name  | | Island | One of four major Hawaiian Islands | | Nativity | Species origin (native or invasive) | | Photo | Photosynthesis, units are micromol CO2 m^-2 s^-1 | | Conductance | Stomatal conductance to water vapor, units are mol m^2 s^-1 | | Transpiration | Transpiration rate, units are mmol H2O m^-2 s^-1 | | WUE | Water use efficiency, Photosynthesis/Transpiration, micromol CO2 mmol^-1 H2O | | SLA | Specific leaf area, units are cm^2 g^-1 | | PerN | Percent leaf nitrogen, units are % | | PerP | Percent leaf phosphorus, units are % | | MEANSPAD | Mean SPAD reading (an index of chlorophyll concentration), unitless. SPAD readings were done on three leaves per individual and averaged. | | LeafCNRatio | Leaf Carbon:Nitrogen Ratio, unitless | | Leaf\_area | Total leaf area of single leaf per individual, units are cm^2 | | LeafThickness | Leaf thickness of one leaf per individual, units are mm | | Rainfall\_meanannual | Mean annual precipitation (primarily rainfall), mm | | Tair\_meanannual | Mean annual air temperature, °C | | SoilpH | Soil pH, unitless | ## Access information Other publicly accessible locations of the data: * NA Data was derived from the following sources: * Data were collected de novo