Data used for hierarchical Bayesian model

The data file includes measurements from monocultures and species-level trait data from the previous studies by the authors. Data description is included in the file

Community Functional Responses to Soil and Climate at Multiple Spatial Scales: When Does Intraspecific Variation Matter?

<div><p>Despite increasing evidence of the importance of intraspecific trait variation in plant communities, its role in community trait responses to environmental variation, particularly along broad-scale climatic gradients, is poorly understood. We analyzed functional trait variation among early-successional herbaceous plant communities (old fields) across a 1200-km latitudinal extent in eastern North America, focusing on four traits: vegetative height, leaf area, specific leaf area (SLA), and leaf dry matter content (LDMC). We determined the contributions of species turnover and intraspecific variation to between-site functional dissimilarity at multiple spatial scales and community trait responses to edaphic and climatic factors. Among-site variation in community mean trait values and community trait responses to the environment were generated by a combination of species turnover and intraspecific variation, with species turnover making a greater contribution for all traits. The relative importance of intraspecific variation decreased with increasing geographic and environmental distance between sites for SLA and leaf area. Intraspecific variation was most important for responses of vegetative height and responses to edaphic compared to climatic factors. Individual species displayed strong trait responses to environmental factors in many cases, but these responses were highly variable among species and did not usually scale up to the community level. These findings provide new insights into the role of intraspecific trait variation in plant communities and the factors controlling its relative importance. The contribution of intraspecific variation to community trait responses was greatest at fine spatial scales and along edaphic gradients, while species turnover dominated at broad spatial scales and along climatic gradients.</p></div

Intraspecific trait responses to environment.

<p>Examples of relationships between trait values of individual species and important environmental predictors are shown for each trait measured in the study: (A) height vs. soil P; (B) leaf area vs. mean annual precipitation; (C) specific leaf area vs. soil pH; (D) leaf dry matter content vs. mean annual precipitation. Points represent site-specific mean trait values of all species sampled in each site. Mean trait values and best fit lines from linear regressions are indicated for the five most abundant and widespread species in the study area: <i>Andropogon virginicus</i>, <i>Poa pratensis</i>, <i>Schedonorus pratensis</i>, <i>Solidago altissima</i>, and <i>Solidago rugosa</i>.</p

Mean, standard deviation, and range of environmental variables included in regression analyses.

<p>Mean, standard deviation, and range of environmental variables included in regression analyses.</p

Relationships between community-weighted mean trait values and environmental variables measured in the study.

<p>Results are shown for the best edaphic and climatic models for each trait as determined by stepwise selection, including the predictor variables retained in each model and the direction of their effects (negative or positive) on the community trait value. Abbreviations: SLA, specific leaf area; LDMC, leaf dry matter content; predictor variables abbreviated as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111189#pone-0111189-t001" target="_blank">Table 1</a>.</p><p>Relationships between community-weighted mean trait values and environmental variables measured in the study.</p

Percentages of total variation in community-weighted mean trait values due to species turnover, intraspecific variation, and their covariation.

<p>Positive covariation indicates that sites dominated by species with high trait values also have individuals with higher than average trait values for their species.</p><p>Percentages of total variation in community-weighted mean trait values due to species turnover, intraspecific variation, and their covariation.</p

Supplement 1. Simulation programming code.

<h2>File List</h2><blockquote> <p><a href="invasion_code.txt">invasion_code.txt</a> S-PLUS (version 6.0) code</p> </blockquote><h2>Description</h2><blockquote> <p>Simulation is described in the original paper and further details are provided in <a href="appendix-A.htm">Appendix A</a>. </p> </blockquote

Appendix A. An explanation of simulation methods.

An explanation of simulation methods

Links between Belowground and Aboveground Resource-Related Traits Reveal Species Growth Strategies that Promote Invasive Advantages

<div><p>Belowground processes are rarely considered in comparison studies of native verses invasive species. We examined relationships between belowground fine root production and lifespan, leaf phenology, and seasonal nitrogen dynamics of <i>Lonicera japonica</i> (non-native) versus <i>L. sempervirens</i> (native) and <i>Frangula alnus</i> (non-native) versus <i>Rhamnus alnifolia</i> (native), over time. First and second order fine roots were monitored from 2010 to 2012 using minirhizotron technology and rhizotron windows. ¹⁵N uptake of fine roots was measured across spring and fall seasons. Significant differences in fine root production across seasons were seen between <i>Lonicera</i> species, but not between <i>Frangula</i> and <i>Rhamnus</i>, with both groups having notable asynchrony in regards to the timing of leaf production. Root order and the number of root neighbors at the time of root death were the strongest predictors of root lifespan of both species pairs. Seasonal ¹⁵N uptake was higher in spring than in the fall, which did not support the need for higher root activity to correspond with extended leaf phenology. We found higher spring ¹⁵N uptake in non-native <i>L. japonica</i> compared to native <i>L. sempervirens</i>, although there was no difference in ¹⁵N uptake between <i>Frangula</i> and <i>Rhamnus</i> species. Our findings indicate the potential for fast-growing non-native <i>Lonicera japonica</i> and <i>Frangula alnus</i> to outcompete native counterparts through differences in biomass allocation, root turnover, and nitrogen uptake, however evidence that this is a general strategy of invader dominance is limited.</p></div

Root coordinates

Provides coordinates and species ids of roots sampled from soil blocks. Variable descriptions are provided in the file