Characteristics of sampling locations for <i>Schoenoplectus californicus</i>; <i>tere</i> = variety <i>tereticulmis</i>; <i>cali</i> = variety <i>californicus</i>.

<p>Characteristics of sampling locations for <i>Schoenoplectus californicus</i>; <i>tere</i> = variety <i>tereticulmis</i>; <i>cali</i> = variety <i>californicus</i>.</p

Means ± standard deviations of nitrogenase activity of epiphytic (roots) and endophytic (rhizomes) diazotrophs measured as ethylene production (nmol C₂H₄ gDW^-1 d^-1), shoot and rhizomes δ¹⁵N, and tissue N and P of <i>Schoenoplectus californicus</i> from unpolluted and polluted locations in the littoral of Lake Atitlán, Guatemala.

<p>Means ± standard deviations of nitrogenase activity of epiphytic (roots) and endophytic (rhizomes) diazotrophs measured as ethylene production (nmol C₂H₄ gDW^-1 d^-1), shoot and rhizomes δ¹⁵N, and tissue N and P of <i>Schoenoplectus californicus</i> from unpolluted and polluted locations in the littoral of Lake Atitlán, Guatemala.</p

Geographic origins of the clones used in the cultivation experiment.

<p>The distribution of <i>Schoenoplectus californicus</i> in the Americas is shown in grey, the dots indicate the sampling locations [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195570#pone.0195570.ref023" target="_blank">23</a>]. The clones included in this study are indicated by letters: Variety <i>tereticulmis</i> EN: Ensenada, Chile; GU: Guillermo, Argentina; PT: Puente, Chile. Variety <i>californicus</i> CC: Copacabana, Bolivia; PU: Puno, Perú; HU: Huanchaco, Perú; SJ: San Juan, Guatemala; RW: Rockefeller, Louisiana.</p

Nitrogenase activity of epiphytic (roots) and endophytic (rhizomes) diazotrophs measured as ethylene production (nmol C₂H₄ gDW^-1 d^-1) associated with <i>Schoenoplectus californicus</i> from unpolluted and polluted locations in the littoral of Lake Atitlán, Guatemala and with its selected varieties in different nutrient treatments of the cultivation experiment.

<p>Nitrogenase activity of epiphytic (roots) and endophytic (rhizomes) diazotrophs measured as ethylene production (nmol C₂H₄ gDW^-1 d^-1) associated with <i>Schoenoplectus californicus</i> from unpolluted and polluted locations in the littoral of Lake Atitlán, Guatemala and with its selected varieties in different nutrient treatments of the cultivation experiment.</p

Soil and plant total nitrogen, TN, and phosphorus, TP, mg g^-1, and aboveground biomass, W, from 52 populations of <i>Schoenoplectus californicus</i> [23].

<p>Soil and plant total nitrogen, TN, and phosphorus, TP, mg g^-1, and aboveground biomass, W, from 52 populations of <i>Schoenoplectus californicus</i> [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195570#pone.0195570.ref023" target="_blank">23</a>].</p

Relationship between nitrogenase activity expressed as ethylene production (nmol C₂H₄ gDW^-1 d^-1) and proportion of <i>nifH</i> genes in total bacterial DNA.

<p>Combined data from Atitlán case study and the cultivation experiment.</p

Means ± standard deviation of nitrogenase activity measured as ethylene production of of epiphytic (roots) and endophytic (rhizomes) diazotrophs from <i>Schoenoplectus californicus</i>, <i>S</i>. <i>acutus</i> and <i>Typha domingensis</i>.

<p>Means ± standard deviation of nitrogenase activity measured as ethylene production of of epiphytic (roots) and endophytic (rhizomes) diazotrophs from <i>Schoenoplectus californicus</i>, <i>S</i>. <i>acutus</i> and <i>Typha domingensis</i>.</p

The proportion of N derived from N₂ fixation (N_dfa). X-axis: Clones Guillermo, GU, Puente, PT and Ensenada, EN are of variety <i>tereticulmis</i>; Copacabana, CC, Rockefeller, RW, San Juan, SJ, Huanchaco, HU, and Puno, PU are clones of variety <i>californicus</i>.

<p>Note the differences in the y-axes. The error bars indicate the standard error of the mean (n = 3).</p

Heterotrophic N₂-fixation contributes to nitrogen economy of a common wetland sedge, <i>Schoenoplectus californicus</i> - Fig 5

<p>Relationship between rhizome nitrogenase activity expressed as ethylene production (nmol C₂H₄ gDW^-1 d^-1).and rhizome δ¹⁵N in <i>Schoenoplectus californicus</i> from the cultivation experiment zero N treatment (A) and high treatment (B). Each nitrogenase activity value is a mean of 3 replicates, isotope data are measured on pooled samples.</p

Differences in microbial community composition in different horizons in arctic soils.

<p>Principal component analysis (PCA) with relative abundances of all PFLA biomarkers. Colors indicate different horizon categories: organic topsoil (O) is dark grey, mineral topsoil (A) is light grey, mineral subsoil (B) is white, and cryoturbated material (J) is black. Symbols indicate sites: circles Cherskiy, diamonds Logata, and triangles Tazovsky. Symbols are the mean values of the coordinates for the individual categories, derived from the PCA with individual samples (n = 101). Error bars are SE. Colors of PLFA markers indicate general markers (grey), gram-positive markers (red), gram-negative markers (orange), bacterial markers (blue) and fungal markers (green).</p