title: Clonal growth: invasion or stability? A comparative study of clonal architecture and diversity in native and introduced lineages of Phragmites australis (Poaceae).
abstract: •
  
  
  OBJECTIVE
  The characteristics of clonal growth that are advantageous in invasive plants can also result in native plants' ability to resist invasion. In Maine, we compared the clonal architecture and diversity of an invasive lineage (introduced Phragmites) and a noninvasive lineage (native Phragmites) present in much of North America. This study is the first on stand-scale diversity using a sample size and systematic spatial-sampling scheme adequate for characterizing clonal structure in Phragmites. Our questions included: (1) Does the structure and extent of clonal growth suggest that the potential for clonal growth contributes to the invasiveness of the introduced lineage? (2) Is clonal growth common in the native lineage, acting as a possible source of ecological resistance and resilience?•
  
  
  METHODS
  Microsatellite markers were used to measure clonal sizes, architecture, and diversity within each lineage in stands within four marshes in Maine.•
  
  
  RESULTS
  Clonal diversity measures indicated that clonal growth was significantly greater in stands of the native lineage than in the introduced. While lineage was a consistent predictor of clonal diversity relative ranking, the marsh location was a much stronger predictor of the absolute range of these values.•
  
  
  CONCLUSIONS
  Our results indicate an important role for clonal growth in the space consolidation of native Phragmites and could explain why the introduced lineage, with stronger competitive traits, has not replaced the native where they co-occur. These results with regard to clone size, size distributions, singleton occurrence, and clonal architecture provide some evidence for stand development that follows a genotypic initial floristics model.
authors.affiliation: Biology Department, Bowdoin College, 6500 College Station, Brunswick, Maine 04011 USA.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Douhovnikoff
authors.affiliation: Department of Watershed Sciences, Ecology Center, Utah State University, Logan, Utah 84322 USA.
authors.forename: Eric L G
authors.initials: EL
authors.lastname: Hazelton
mesh_terms: D000222:Adaptation, Physiological; D014644:Genetic Variation; D005838:Genotype; D058865:Introduced Species; D008281:Maine; D018895:Microsatellite Repeats; D008954:Models, Biological; D010641:Phenotype; D006109:Poaceae / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D053833:Wetlands
keywords: Phragmites; Poaceae; clonal growth; clonal structure; introduced; invasive; native; resilience; resistance; stand development