Feral pig (Sus scrofa) disturbance facilitates establishment of resource-acquisitive species in Hawaiian forest understories

In this study, we quantify the effects of leaf traits and dispersal attributes on species responses to pig soil disturbance at two spatial scales – 0.5 m2 patches embedded along 20 m transects within sites – across a gradient of pig density in a Hawaiian montane wet forest using Bayesian mixed models. 
Native and non-native species demonstrated divergent responses, with increasing presence and abundance of non-native species in the understory as soil disturbance within patches and sites increased. Dominant patterns in measured traits tracked the leaf economic spectrum (LES), with non-native species tending toward resource-acquisitive traits. Species with resource-acquisitive traits, regardless of identity, were favored with disturbance and responded positively to light availability in disturbed sites. Models showed species primarily dispersed by wind were more prevalent in disturbed patches and sites than those dispersed by endozoochory, while seed mass had no effect., From Methods outlined in the publication:
Data Collection
The impacts of pig activity and disturbance vary by scale, and effects on community composition are mediated in part by differences in establishment success due to disturbance within habitat patches. To capture these effects, we used a hierarchical design incorporating pig density at the zone level, our broadest spatial scale, and pig soil disturbance (i.e. physically overturned soil as a result of pig activity) at two consecutively smaller scales: (i) within sites nested within zones (hereafter, Dsite), and (ii) within habitat patches nested within sites (hereafter, Dpatch). Four zones with 1-km radii, roughly equal to conservative estimates of pig home-range size in Hawaiian forests, were established within the study site (Fig. 1A) (Diong, 1982). To capture patterns in understory composition and soil disturbance at the site- and patch-scale, we surveyed 30 sites within each zone using a stratified-random design (1 additional si..., , # Feral pig (Sus scrofa) disturbance facilitates establishment of resource-acquisitive species in Hawaiian forest understories

Datasets Included:

1\) abundance ('hits' from point-intercept estimates) of understory plant species at sites (named \"Site-scale.csv\"):

* Site: Site where data were collected (treat as a factor)
* Dsite: site-scale disturbance given by summed lengths of transect segments intersecting disturbance at each site (in meters)
* NLsite: nurse log given by summed lengths of transect segments intersecting nurse logs (in meters)
* Pig_Density: population density estimates given by REM (individuals per km2)
* Lightsite: canopy openness from 3 hemispheric photographs averaged across the site (%)

The species-level abundances are in the remaining columns, given as 'hits' from point-intercept approach.

2\) presence/absence of plant species rooted in patches (named \"Patch-scale.csv\"):

* Site: Site where data were collected (treat as a factor)
* Patch: Patc...