Electronic Supplementary Material from Ecological drift and the distribution of species diversity

Supplemental methods, tables and figure

compiled abundance data drift experiment

Species abundances by treatment (community size), block and yea

Appendix B. Mean and standard error values for the competitive coefficients and vital rates calculated to parameterize our annual plant population model.

Mean and standard error values for the competitive coefficients and vital rates calculated to parameterize our annual plant population model

Chloroplast haplotypes.

<p>(A) Haplotype network based on statistical parsimony. Circle size corresponds to the number of genotyped individuals with that particular haplotype, while nodes between circles represent the number of changes separating two haplotypes. (B) Distribution of haplotypes across sampled populations in Switzerland. Each pie chart corresponds to one of the sampled populations.</p

Mean log tiller growth rates of the transplants by species and precipitation treatment.

<p>Bars show empirical standard errors. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006887#pone-0006887-t001" target="_blank">Table 1</a> contains full statistical results.</p

Analysis of covariance results for biomass, with tiller numbers as the covariate.

<p>Analysis of covariance results for biomass, with tiller numbers as the covariate.</p

Mean aboveground biomass of the transplants by species and treatment.

<p>Bars show empirical standard errors. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006887#pone-0006887-t002" target="_blank">Table 2</a> contains full statistical results.</p

Population genetics and adaptation to climate along elevation gradients in invasive <i>Solidago canadensis</i>

<div><p>Gene flow between populations may either support local adaptation by supplying genetic variation on which selection may act, or counteract it if maladapted alleles arrive faster than can be purged by selection. Although both such effects have been documented within plant species’ native ranges, how the balance of these forces influences local adaptation in invasive plant populations is less clear, in part because introduced species often have lower genetic variation initially but also tend to have good dispersal abilities. To evaluate the extent of gene flow and adaptation to local climate in invasive populations of <i>Solidago canadensis</i>, and the implications of this for range expansion, we compared population differentiation at microsatellite and chloroplast loci for populations across Switzerland and assessed the effect of environmental transfer distance using common gardens. We found that while patterns of differentiation at neutral genetic markers suggested that populations are connected through extensive pollen and seed movement, common-garden plants nonetheless exhibited modest adaptation to local climate conditions. Growth rate and flower production declined with climatic distance from a plant's home site, with clones from colder home sites performing better at or above the range limit. Such adaptation in invasive species is likely to promote further spread, particularly under climate change, as the genotypes positioned near the range edge may be best able to take advantage of lengthening growing seasons to expand the range.</p></div

Photos of common gardens.

<p>(A) Lowest garden, June 25, 2013. Plants just starting to send up shoots. (B) Lowest garden, September 9, 2013. Inflorescences covered with mesh bags to reduce pollination and prevent seed dispersal. (C) Highest garden, August 26, 2013. Notice that none of the plants have inflorescence buds. (D) Middle elevation garden, October 14, 2013. Stems knocked over by first snowfall.</p

Location and seedling density for one replicate (Fig. 1B)

Number of seedlings in each pot in each generation for one replicate array in the experiment (continuous landscape, evolving treatment), as in Figure 1B. Seedlings were counted in 1 cm wide bins at the leading edge, and counted for the entire pot behind the leading edge. See ReadMe associated with 'Furthest seed' datafile for metadata