Genetic diversity by tallgrass prairie community structure associations.

<p>Scatter plots representing genetic diversity (<i>H′_ISSR</i>) by tallgrass prairie community structure (<i>H′, S, D</i>) growing in plots sown with cultivar (filled) and local ecotypes (open) of the dominant grasses.</p

Principal coordinate analysis of <i>Chamaecrista fasciculata</i> and <i>Silphium integrifolium</i> based on ISSR band frequency data.

<p>Genetic relationships of <i>Chamaecrista fasciculata</i> (A) and <i>Silphium integrifolium</i> (B) growing in plots sown with cultivar (filled) and local ecotype (open) dominant grasses.</p

Genetic Sorting of Subordinate Species in Grassland Modulated by Intraspecific Variation in Dominant Species

<div><p>Genetic variation in a single species can have predictable and heritable effects on associated communities and ecosystem processes, however little is known about how genetic variation of a dominant species affects plant community assembly. We characterized the genetic structure of a dominant grass (<i>Sorghastrum nutans</i>) and two subordinate species (<i>Chamaecrista fasciculata</i>, <i>Silphium integrifolium</i>), during the third growing season in grassland communities established with genetically distinct (cultivated varieties or local ecotypes) seed sources of the dominant grasses. There were genetic differences between subordinate species growing in the cultivar versus local ecotype communities, indicating that intraspecific genetic variation in the dominant grasses affected the genetic composition of subordinate species during community assembly. A positive association between genetic diversity of <i>S. nutans</i>, <i>C. fasciculata</i>, and <i>S. integrifolium</i> and species diversity established the role of an intraspecific biotic filter during community assembly. Our results show that intraspecific variation in dominant species can significantly modulate the genetic composition of subordinate species.</p></div

Field experimental design with three species pools (A,B,C) planted with local ecotype or cultivar grasses.

<p>The two subordinate species were sampled from their respective species pools (<i>Chamaecrista fasciculata</i>-A, <i>Silphium integrifolium</i>-B); the ‘Rumsey’ <i>Sorghastrum nutans</i> cultivar and local ecotype individuals were sampled across all three replicated species pools.</p