now includes rows for germination and survival to the last census as functions of species (random), phylogenetic distance to the species at the planting site, and the species × phylogenetic distance (random) interaction. The corrected table appears below. This error does not affect the conclusions of the article. , predicting the arcsin sqrt transformed proportion germination or proportion of seedlings at the last census. Chi-squared values to test the random effects were calculated as the difference in likelihoods between models with and without the tested effect with 1 df (2). Residuals were less heteroscedastic in chosen models than alternate (sqrt or logit) transformations. There was a main phylogenetic distance effect with a negative slope, with species germinating and surviving to the last census in greater numbers at home and close relatives sites than at distant relatives' sites. There was no interaction in either model between phylogenetic distance and species, indicating a general negative germination and early survival response to environments occupied by distant relatives across all 32 species investigated. Alternative models with generalized linear mixed models (GLMM, lmer, library lme4) with binary response variable, binomial error distribution, and logit link function also yielded a significant negative relationship between phylogenetic distance and total germination and germination and survival to the last census (R Version 2.11.0). Nonparametric approaches also support these conclusions; 24 of 32 species had negative slopes for the relationship between total germination and phylogenetic distance (sign test, P = 0.004); 25 of 32 species had negative slopes for the relationship between germination and survival to the last census and phylogenetic distance (sign test, P = 0.001) in the GLMM.www.pnas.org PNAS | February 28, 2012 | vol. 109 | no. 9 | 3599-3600 CORRECTIONS

Summary 1.General guidelines for invasive plant management are currently lacking. Population declines may be achieved by focusing control on demographic processes (survival, growth, fecundity) with the greatest impact on population growth rate. However, we often have little demographic information on populations in the early stages of an invasion when control can be most effective. Here we determine whether synthesis of existing demographic data on invasive and native plant populations can address this knowledge problem. 2. We compared population dynamics between invasive and native species using published matrix population models for 21 invasive and 179 native plant species. We examined whether the population growth rate responsiveness to survival, growth and fecundity perturbations varied between invasive and native species, and determined which demographic processes of invaders to target for reductions in population growth rate. 3. Invaders had higher population growth rates ( λ ) than natives, resulting in differences in demographic processes. Perturbations of growth and fecundity transitions (elasticities) were more important for population growth of invaders, whereas perturbations of survival had greater importance for population growth of natives. 4. For both invasive and native species, elasticities of λ to survival increased with life span and decreased with λ ; while elasticities to growth and fecundity decreased with life span and increased with λ . 5. For long-lived invaders, simulated reductions in either survival, growth or fecundity transitions were generally insufficient to produce population declines, whereas multiple reductions in either survival + growth or survival + fecundity were more effective. For short-lived invaders, simulated reductions in growth or fecundity and all pairwise multiple reductions produced population declines. 6. Synthesis and applications . Life history and population growth rate of invasive species are important in the selection of control targets. For rapidly growing populations of short-lived invaders, growth and fecundity transitions should be prioritized as control targets over survival transitions. For long-lived invaders, simultaneous reductions in more than one demographic process, preferably survival and growth, are usually required to ensure population decline. These general guidelines can be applied to rapidly growing new plant invasions and at the invasion front where detailed demographic data on invasive species are lacking.

Little is known about the traits and mechanisms that determine whether or not a species will be invasive. Invasive species are those that establish and spread after being introduced to a novel habitat. A number of previous studies have attempted to correlate specific plant traits with invasiveness. However, many such studies may be flawed because they fail to account for shared evolutionary history or fail to measure performance directly. It is also clear that performance is context dependent. Thus, an approach that corrects for relatedness and incorporates multiple experimental conditions will provide additional information on performance traits of invasive species. I use this approach with two or three pairs of invasive and closely related non‐invasive species of Commelinaceae grown over experimental gradients of nutrient and water availability. Invasive species have been introduced, established, and spread outside their native range; non‐invasive species have been introduced, possibly (but not necessarily) established, but are not known to have spread outside their native range. The invasive species had higher relative growth rates (RGR) than non‐invasive congeners at high nutrient availabilities, but did not differ from non‐invasive species at low nutrient availabilities. This is consistent with a strategy where these particular invasive species are able to rapidly use available resources. Relative growth rates were also higher for two out of three invasive species across a water availability gradient, but RGR did not differ in plasticity between the invasive and non‐invasive species. This suggests that nutrient addition, but not changes in water availability, might favour invasion of dayflowers. This approach is novel in comparing multiple pairs of invasive and non‐invasive congeners across multiple experimental conditions and allows evaluation of the robustness of performance differences. It also controls for some of the effects of relatedness that might confound multispecies comparisons.

Explaining variation in population growth rates is fundamental to predicting population dynamics and population responses to environmental change. In this study, we used matrix population models, which link birth, growth and survival to population growth rate, to examine how and why population growth rates vary within and among 50 terrestrial plant species. Population growth rates were more similar within species than among species; with phylogeny having a minimal influence on among-species variation. Most population growth rates decreased over the observation period and were negatively autocorrelated between years; that is, higher than average population growth rates tended to be followed by lower than average population growth rates. Population growth rates varied more through time than space; this temporal variation was due mostly to variation in post-seedling survival and for a subset of species was partly explained by response to environmental factors, such as fire and herbivory. Stochastic population growth rates departed from mean matrix population growth rate for temporally autocorrelated environments. Our findings indicate that demographic data and models of closely related plant species cannot necessarily be used to make recommendations for conservation or control, and that post-seedling survival and the sequence of environmental conditions are critical for determining plant population growth rate.

Abstract. Recent studies of communities have examined phylogenetic signal in species' functional traits to infer drivers of community assembly. Phenotypic variation in traits, arising from ''constitutive'' genetically based variation and from environmental influences on gene expression, or phenotypic plasticity, could affect inferences about community assembly. We found significant trait plasticity in 12 focal species across four species-interaction treatments grown in four soil environments. Phylogenetic signal in traits was present, but was also dependent on species-interactor treatment, suggesting that phenotypic plasticity and plant neighborhood could affect the ability to detect and interpret community phylogenetic patterns of trait variation. Individuals competing with conspecifics expressed significant divergence in specific leaf area (SLA) relative to when they were grown alone. Combined with the observation that competition is stronger between close relatives than between distant relatives in some soils, these results suggest that trait plasticity may be an adaptive response to competition. To test this hypothesis, we examined total biomass in a pot, relative to the predicted biomass of two individuals grown alone, and related pot biomass to phylogenetic distance of the interactor treatment, as well as to divergence in SLA and root : shoot ratio. Within competition treatments, only plastic divergence in root : shoot ratio in one interactor treatment was correlated with increased productivity, and only in one soil type. We also tested whether, across all treatments, divergence in SLA or root : shoot ratio increased pot productivity. We found that ''community'' productivity was positively influenced both by phylogenetic distance to competitor, as well as by divergence in root : shoot ratio due to both plasticity and constitutive differences. Phenotypic plasticity resulting in trait divergence may increase the ability of plants to coexist and may also decrease phylogenetic signal in community assembly at small spatial scales.