Competitive effects as indicated by relative interaction intensity (means +1 SE, n = 10) under eight different combinations consisting of sterilization, species identity, and soil source.

<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015418#pone-0015418-t001" target="_blank">Table 1</a> for ANOVAs.</p

Three-way ANOVAs for the effects of sterilization, species identity (SI), soil source (SS), and their interactions on seedling emergence, total biomass per plant, and relative interaction intensity.

<p>Three-way ANOVAs for the effects of sterilization, species identity (SI), soil source (SS), and their interactions on seedling emergence, total biomass per plant, and relative interaction intensity.</p

Seedling emergence (means +1 SE, n = 5) under eight different combinations consisting of sterilization, species identity, and soil source.

<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015418#pone-0015418-t001" target="_blank">Table 1</a> for ANOVAs.</p

Root weight ratio of the invasive plant <i>Eupatorium adenophorum</i> and the native plant <i>Eupatorium chinense</i> grown in four different air temperatures.

<p>Data are means+1 SE. ns = not significant; * <i>P</i><0.05.</p

Plant height of the invasive plant <i>Eupatorium adenophorum</i> and the native plant <i>Eupatorium chinense</i> grown in four different air temperatures, and changes in plant height with warming for both species (embedded smaller panel inside).

<p>Data are means+1 SE. ns = not significant; * <i>P</i><0.05; *** <i>P</i><0.001.</p

Whole-plant biomass of the invasive plant <i>Eupatorium adenophorum</i> and the native plant <i>Eupatorium chinense</i> grown in four different air temperatures, and changes in whole-plant biomass with warming for both species (embedded smaller panel inside).

<p>Data are means+1 SE. * <i>P</i><0.05; *** <i>P</i><0.001.</p

Competitive effects of <i>Centaurea maculosa</i> populations from Europe and North America under either the ambient (A) or warming condition (B), and the change in competitive effects for <i>C. maculosa</i> populations with warming (C).

<p>Means and 1 SE for each population are presented in the narrow bars, and means and 1 SE for each continent using the means of each population as replicates are presented in the two thicker bars in the center of the figure. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0031170#pone-0031170-t001" target="_blank">Table 1</a> for ANOVAs.</p

The relationship between the change in biomass with warming versus the change in competitive effects and competitive responses with warming for <i>Centaurea maculosa</i> populations from Europe and North America.

<p>The relationship between the change in biomass with warming versus the change in competitive effects and competitive responses with warming for <i>Centaurea maculosa</i> populations from Europe and North America.</p

Analysis of variance (ANOVA) of the whole-plant biomass of individual plants, change in whole-plant biomass with warming, competitive effects, change in competitive effects with warming, competitive responses, and change in competitive responses with warming of <i>Centaurea maculosa</i> populations.

<p>Values of <i>P</i><0.05 are in bold.</p><p>*“1,160” is the degree of freedom for two-way ANOVAs, “1,84” is the degree of freedom for one-way ANOVAs.</p

The competitive effects, as indicated by relative interaction intensity (RII = (<i>B_w</i>−<i>B_o</i>)/(<i>B_w</i>+<i>B_o</i>)), of different <i>C. stoebe</i> populations on the four North American (NA) species across three nitrogen levels.

<p>Bars show means+1 SE for each <i>C. stoebe</i> population. RII was calculated for each population in competition with a given NA species across three N levels, and <i>B_w</i> and <i>B_o</i> were the biomass of a plant of a given NA species in competition with a <i>C. stoebe</i> plant and the mean biomass of all the plants of a given NA species grown alone.</p